2019 CAP Congress / Congrès de l’ACP 2019
Sunday, 2 June 2019 - Friday, 7 June 2019 Simon Fraser University
Book of Abstracts ii Contents
Frugal Science in the Age of Curiosity / La science frugale à l’ère de la curiosité . . . . . 1
R(D(∗)) measurement at the Belle II Detector ...... 1
WITHDRAWN - Symmetry restoration in mixed-spin paired heavy nuclei ...... 2
Quantum cryptography in realistic conditions with structured photons ...... 2
To Flip or not to Flip: Video Experiments in Physics Teacher Education ...... 3
WITHDRAWN - Estimation of interdiffusion variables for tungsten - glassy carbon couples ...... 3
35 - Plasmon-Enhanced Stimulated Raman Spectroscopy with Low-Power CW Lasers . . 4
Modeling the slow cytotoxic swelling of dystrophic muscle fibers ...... 4
Probing the Strangeonium Hybrid Content of the Y(2175) Using Gaussian Sum-Rules . . 5
Reducing dissipation in far-from-equilibrium biomolecular processes ...... 5
9 - Game of Hadrons ...... 6
About the definition of a ”local” temperature around a spacecraft in the ionosphere . . . 6
Studying the brain across scales using imaging and physics ...... 7
An Analytic Study of the Fourier Transform of the Gravitational Wave Pulsar Signal with Spin-down Effects ...... 7
32 - Localizing and excluding quantum information; or, how to share a quantum secret in spacetime ...... 8
6 - Experimental Detection of Qubit-Ququart Pseudo-Bound Entanglement using Three Nuclear Spins ...... 8
A Visualization of the Belle II Detector Through Photon Conversions ...... 9
Engaging undergraduates in science using advanced in-class demonstration technology 9
27 - Exact Diagonalization on Pyrochlore System ...... 10
Double Spectrum Digraph of Quantum Group Gravity ...... 10
iii Wake Field and Trapped Resonant Mode Calculations for the BioXAS in-Vacuum Undulator ...... 11
Reforming Intro Physics Labs to Focus on Innovation, Creativity, and Scientific Skills . . 11
Physics Students as Museum Curators ...... 11
Dark matter in a dark sector ...... 12
Dark Sector Searches on ATLAS ...... 12
Conduction electrons are entirely responsible for the heat generated by a constant electric current flowing in a wire ...... 12
Cyclotrons for Medicine ...... 13
Four-way high-fives during exams: Adding a group phase to provide immediate feedback and increase enjoyment ...... 13
Dark sector, dark matter, and related searches at Belle II ...... 14
Electronic , Optical and Magnetic Properties of low concentration Ni doped CdSe by First Principle Method ...... 14
Searches for Dark Sectors in Fixed-Target Experiments ...... 15
Possible Flexoelectric Origin of the Lifshitz Transition in Strontium Titanate Interfaces . 15
Anti-neutrino Energy Spectrum and Ground State Branching Ratio of Laser Trapped 92Rb → 92 − Srβ ν¯e ...... 16
Operational, gauge-free quantum tomography ...... 16
Run-2 physics results from the ATLAS experiment at the Large Hadron Collider . . . . . 17
Interacting Gravitational Waves ...... 17
Physics outreach and Gender: Tribute to Dr. Li-Hong Xu ...... 17
Axon Diameter Inferences in the Corpus Callosum and Fornix of the Mouse Brain from Images with Low SNR ...... 18
21 - Mass, Light and Gravity in Unitary Space-Time ...... 18
The Packing of Soft Spheres ...... 19
Indirect searches for dark matter: annihilation, decay and collider production ...... 19
Nuclear structure and dynamics from ab initio theory ...... 20
John D’Auria, the relativistic chemistry of francium, and MeV-mass neutrinos ...... 20
Upgrades to the ATLAS Detector at the Large Hadron Collider ...... 21
Electrokinetic transport in porous media ...... 21
Limits on exotic contributions to electroweak symmetry breaking ...... 22
iv Astronomical observations: an introduction for physicists ...... 22
Overview of Dark Matter Direct Detection ...... 23
Dynamical spin effects in the pion light-front wavefunction ...... 23
Pierluigi Falco (1977-2014) and his Contributions to Mathematical Physics ...... 23
β-NMR Studies of the Temperature and Depth Dependence of Dynamics in Polystyrene Thin Films ...... 24
70 - WITHDRAWN - Search for dark matter in events with missing transverse momentum and a Z boson produced in 13 TeV proton-proton collisions with the ATLAS detector at the LHC ...... 24
Neutrino Oscillations at T2K and Hyper-K ...... 25
Simultaneous Positron Emission Tomography (PET)/Magnetic Resonance (MR) Imaging 25
1 - Magnetic shield changes with time and temperature ...... 26
Status of the Belle II experiment and overview of early semi-leptonic and leptonic results 26
The role of physics in Nuclear Medicine ...... 27
Molecular machinery: quantifying the energetic cost of controlling nanoscale biological systems ...... 27
Maxwell’s demon in the real world: Experiments on control, information, and thermody- namics...... 27
Influence of the neutron pf shell on the structure of28Mg ...... 28
WITHDRAWN - Performance of Canadian-made muon detectors for the Phase-1 upgrade of the ATLAS detector ...... 28
Ultra-broad bandwidth lasers opening up an easier path to laser fusion ...... 29
Citizen Science with the Canadian Collaborative Occultation Network ...... 29
Dark matter search results from DEAP-3600 at SNOLAB ...... 30
UV spectroscopy of cold aromatic molecular systems as a diagnostic of size, functional group, and charge effects...... 30
Optical Interactions in Graphene ...... 31
John D’Auria and his legacy ...... 31
22 - Mass, light and Gravity in Unitary space-time– (Part II) ...... 32
36 - Improving Optical Pumping Methods for Nuclear Beta Decay ...... 32
New Physics In Higgs Decays to Leptons ...... 33
Determination of the Physics Reach of the PICO-40L and PICO-500 Bubble Chamber Dark Matter Detectors ...... 33
v History of µSR: Applied Particle Physics ...... 33
Multi-PMTs for NuPRISM/E61 ...... 34
FTIR Synchrotron Spectroscopy of the Lower Modes of Methyl-D3 Mercaptan (CD3SH) – Where is the C-S Stretch? ...... 34
WITHDRAWN - Bose-Einstein Condensates as Gravitational Wave Detectors ...... 35
Potential Model Tetraquark Mass Predictions Using Doubly Heavy Diquark Masses from QCD Sum Rules ...... 35
WITHDRAWN - Search for dark sector particles in Higgs boson decays with the ATLAS detector at the LHC ...... 36
Design and synthesis of an artificial molecular motor: The Lawnmower ...... 36
83 - AmBe Source Calibrations in Measuring Reactor Antineutrinos in SNO+ Water Phase 37
Electron EDM Experiment using Francium at TRIUMF ...... 37
Incompressible Even Denominator Fractional Quantum Hall States in the Zeroth Landau Level of Monolayer Graphene ...... 38
Black Holes and the Entangling Structure of Spacetime ...... 38
74 - IN SITU MEASUREMENTS OF THE ATLAS JET ENERGY RESOLUTION USING 13 TeV PP DATA ...... 38
A connection between linearized Gauss–Bonnet gravity and classical electrodynamics . 39
Mass measurements with the Canadian Penning Trap mass spectrometer to study the as- trophysical r process ...... 39
Free energy cost of localizing a single monomer of a confined polymer ...... 40
Thinking of Li-Hong in Outreach Activities from the 5th Grade in Nova Scotia toKath- mandu and the work of IUPAP on Physics for Development ...... 41
Early Days of the TRIUMF Cyclotron ...... 41
Using an embedded expert to redesign physics undergraduate lab curriculum and build an intellectual community ...... 41
75 - A Neutron calibration system for the Cryogenic Underground TEst facility (CUTE) . 42
Orientationally ordered states of a wormlike chain inside spherical confinement . . . . . 42
+ + Prospects of search for B → µ νµ decay with the Belle II experiment ...... 43
Stress Evaluation of ITK Strip Endcap R0 modules in Coldbox Setup Using FEA Simulations for the ATLAS Detector Phase-II Upgrade ...... 43
Unravelling the mechanical properties of collagen with centrifuge force microscopy . . . 44
Rare Isotope Production at ISAC/TRIUMF ...... 44
Investigating the Nuclear Shell Closure at N=32 in Neutron-Rich 52Ca ...... 45
vi WITHDRAWN - Results of the 2018 ATLAS sTGC Beam Tests ...... 46
Applications of Modern Optical Microscopy in Biology ...... 46
Commissioning and initial operation of the EMMA recoil mass spectrometer ...... 47
A study of spin-pumping in Py/Pt and Py/Pt/Py structures ...... 47
Black holes in a rotating and expanding spacetime ...... 48
Li-Hong Xu - A Light in the East ...... 48
What Is the Condition for Conservation of Momentum? ...... 49
Measuring the anti-muon-neutrino induced charged-current coherent pion production us- ing the T2K near detector ...... 49
Towards an Asymptotically Safe Standard Model ...... 49
Physicists and the first Pugwash Conference in 1957 ...... 50
Strongly-coupled superconductivity from quantum cluster approaches ...... 50
Introduction to 3D Digital SiPM and Latest Results for Particle Physics ...... 51
Elastic Properties of Natural Biotite Crystals by Brillouin Spectroscopy ...... 51
Integration and Evaluation of Coding in First Year Integrated Physics and Calculus Courses...... 52
10 - Engaging reflective thinking during exam-like situations: Slowing students downon short-answer questions increases performance ...... 52
Engaging reflective thinking during exam-like situations: Slowing students down onshort- answer questions increases performance ...... 53
28 - Axial EBIC oscillations at core/shell GaAs/Fe nanowire contacts ...... 53
Improvement of missing transverse momentum reconstruction for ATLAS experiment at LHC ...... 54
The search for exotic dilepton signatures in the full LHC Run-2 dataset collected withthe ATLAS detector ...... 54
Quantum Diffractive Collision Universality and the Quantum Pascal ...... 54
Goals and Scope of the Light-Only Liquid Xenon Project ...... 55
A Supernova Calibration Source for SNO+ ...... 56
Dark matter from Kalb-Ramond gauge symmetry ...... 56
The GlueX Experiment: A Search for Exotic Matter ...... 56
Assessing affective contributions to gender inequalities in introductory physics courses . 57
Experimental demonstration of a quantum optics solution to the partition problem . . . 57
vii E61 Status and Sensitivity Studies ...... 58
Tests of fundamental physics with trapped antihydrogen ...... 58
Investigation of High-Lying ( , ) Resonances in 22Ne via High-Resolution Gamma Ray Spectroscopy in Inverse Kinematics ...... 59
Time-Dependent Artificial Gauge Fields in Ultracold Quantum Gases ...... 59
Strong fields for spectroscopy ...... 60
Stable negative mass solutions in de Sitter spacetime ...... 60
New Gravitational Probes of Dark Matter ...... 61
Conceptual Understanding Through Visual Reasoning: An Example from Quantum Me- chanics ...... 61
71 - Multi-Bubble Reconstruction in PICO Bubble Chambers ...... 61
Production and purification of radium-225 and actinium-225 at TRIUMF’s Isotope Sepa- ration On-line (ISOL) facility and subsequent radiolabeling studies with alpha-emitter actinium-225 ...... 62
WITHDRAWN - Low Threshold Analysis with DEAP-3600 ...... 62
Vector Boson Scale Factor Measurement with the ATLAS Detector ...... 63
Alpha backgrounds in DEAP-3600 ...... 63
50 - A First Realization of a Quantum Pressure Standard ...... 64 nEXO’s Outer Detector: Status and Prospects ...... 64
Measurement of the single electron response of Spherical Proportional Counters for the NEWS-G light dark matter search experiment ...... 65
Quantitative Magnetic Resonance Imaging ...... 65
Topological Structures and Dynamics of Spatially Structured Optical Beams ...... 65
Cosmological Bounds on Non-Abelian Dark Forces ...... 66
84 - On the Neutrino Floor for the Next Generation of Liquid Noble Dark Matter Experi- ments ...... 67
Frustrated magnetism on 2D triangular, metallic antiferromagnets ...... 67
Anomalous transport property in Re3Ge7 ...... 67
Life with a Scientific Cyclone: Personal reflections on my collaborations with John D’Auria ...... 68
Single-particle structure of 93,94,95Sr nuclei ...... 68
Physical properties of Yb3Ru4Ge13 and Lu3Ru4Ge13 ...... 69
24 - Einstein-Maxwell-dilaton solution in Bianchi type IX ...... 70
viii Cardiorespiratory Fitness Evaluation using Submaximal protocol with Muscle Oxygenation ...... 70
Analog Electronics and SiPM Characterization for LOLX ...... 71
Decay Spectroscopy of Neutron-Rich Cd Around the N = 82 Shell Closure with GRIFFIN 71
Mass Measurements of Neutron-Rich Indium Isotopes for Enhanced r-Process Studies . . 72
Atomic force microscopy reveals how structural variations impact the flexibility of collagen ...... 73
76 - Measurement of SuperKEKB Electron Beam Polarization through Tau Forward-Backward Polarization Asymmetry ...... 74
Li-Hong as a supporter of Asian Arts: A dance dedication ...... 74
Do the temperature dependencies of spectral line parameters change when we approach cryogenic temperatures? ...... 75
Li-Hong Xu as a mentor and scholar ...... 75
Searching for new physics with next generation CMB experiments ...... 76
UBC High School Physics Olympics: Past, Present, and Future ...... 76
First Order Relativistic Correction to Landau Levels in the Presence of a Parallel Linear Electric Field ...... 77
WITHDRAWN - 2H NMR investigation of the phase behaviour of phospholipid membranes containing cholesterol and ceramide ...... 77
High-precision mass measurement of n-rich Rb & Sr isotopes at TITAN ...... 78
Interplay between native state topology and sequence in two-state protein folding . . . . 79
Development of 7 Tesla Magnetic Resonance Imaging Guided Robotic System ...... 79
Conductivity of a perfect crystal ...... 80
2 - Determination of Activity Concentrations in Selected Rock Samples from Quarry Sites in Ibadan, Nigeria ...... 80
Updates from SNOLAB ...... 81
Direct plasmon production from Thomson scattering in SuperCDMS silicon detectors . . 81
WITHDRAWN - Water Cherenkov Detector Calibration for Super-Kamiokande and Hyper- Kamiokande ...... 81
SuperCDMS SNOLAB: the search for low-mass dark matter particles ...... 82
Valley filters, accumulators, and switches induced in graphene quantum dots by linesof adsorbed hydrogen atoms ...... 82
37 - Ion beam injection and extraction simulations in TITAN’s cooler Penning trap . . . 83
Search for Magnetic Monopoles and High Electric Charge Objects in the ATLAS Detector 83
ix Progress on ultracold neutrons at TRIUMF ...... 84
Development of multi-detector systems for radiation measurements at Simon Fraser Uni- versity ...... 84
62 - EMPHATIC detector development ...... 85
An Improved Extraction of the Vud CKM Matrix Element ...... 85
Laws of Black Hole Thermodynamics in Semiclassical Gravity ...... 85
Effect of temperature on plasmonic resonances in semiconductors and metals ...... 86
87 - Concentration of Cells and Elimination of Extraneous Background Signals in Laser- Induced Breakdown Spectroscopy to Identify, Differentiate and Detect Bacteria . . . 87
Cavity Spintronics: Foundations and Applications of Spin-Photon Hybridization . . . . . 87
Computing Conformal Blocks through Geodesic Witten Diagrams ...... 88
The Canadian Neutron Beam Centre at Chalk River ...... 89
Characterizing the SNOLAB radiation environment ...... 89
51 - Precision characterization of the linear-zigzag transition in ultracold trapped ion crys- tals ...... 89
Terahertz conductivity measurements of MnSi ...... 90
Asymptotic Safety in the Conformal Hidden Sector ...... 90
52 - Electron plasma studies for a cooler Penning trap at TITAN ...... 91
Analysis of Plasmonic and Plasma Assisted Photoacoustic Response from Metallic Nanos- tructures Irradiated by Fast and Ultrafast Laser ...... 91
Nanoscale Surface Morphology Induced by Poor Solvents on Glassy Polymer Films . . . 92
Crystallization Studies of Highly Monodisperse Oligomeric Poly(Ethylene Oxide) . . . . 92
Light-cone like spreading of correlations in the Bose-Hubbard model at strong coupling 93
77 - Position resolution in the DEAP-3600 dark matter experiment ...... 93
Laser cooling of antihydrogen using pulsed VUV radiations ...... 94
A new electron gun for the TITAN-EBIT ...... 94
Resonance Ionization Laser Ion Source – pure radioactive ion beams & in-source laser spec- troscopy ...... 95
Gas Cell Based on Hollow-Core Fiber for Trace Gas Detection ...... 95
Photonic Device for Gas Detection ...... 96
Statistical physics of a driven nanocolloid coupled to a fluid heat bath ...... 96
Methods to constrain thermonuclear rates (by and for John D’Auria) ...... 97
x 25 - Level Attraction and Synchronization in Hybridized Magnon-Photon Systems . . . . 98
Finite Size Kosterlitz-Thouless Transition in Fe/W(001) Ultrathin Films ...... 98
Measurements of the first polarized ultracold neutrons at TRIUMF ...... 99
Novel AFM-Intermodulation Technique for Nanoscale Characterization of Surface Proper- ties ...... 99
Bert Brockhouse and the Early History of Canadian Neutron Scattering - a personal view 100
A combined local-macroscopic approach to investigate plasticity of athermal amorphous solids ...... 100
17 - Effect of CT Injection on Dusty Plasma in the STOR-M Tokamak ...... 101
63 - Photoneutron calibration of SuperCDMS detectors ...... 102
The Barrel Scintillator Veto for the ALPHA-g experiment ...... 102
Entanglement entropy on the noncommutative sphere ...... 103
14 - DC magnetron discharge used for nanoparticle growth: comparison of particle- in-cell simulations with experimental measurements ...... 103
Investigating Novel Anion-Exchange Membranes via Scattering and Simulation . . . . . 104
CUTE Status and Plans ...... 105
WITHDRAWN- Shape coexistence in the Pb region: A systematic study of the even 188−200Hg with GRIFFIN ...... 105
Modelling Cherenkov in DEAP-3600 ...... 106
Improving the sensitivity of the neutron electric dipole moment experiment at TRIUMF 107
Violation of Ohm’s law in a Weyl metal ...... 107
”Black holes, wormholes and solid state realizations of Sachdev-Ye-Kitaev models” . . . . 108
Machine Learning as a Tool to Study Soft Matter in Confinement ...... 108
29 - Shallow donor complexes in ZnO containing Sn and Li studied by photoluminescence and density functional theory ...... 108
30 - Violation of Ohm‘s law in a Weyl metal ...... 109
Emergent electronic states in chalcogenide/oxide heterostructures ...... 110
3 - Upgrade of the electrostatic spectrometer and ion/shakeoff detectors in TRIUMF’s neu- tral atom trap apparatus...... 110
SPECTROSCOPY OF 98Ru ...... 111
Spectroscopic studies of the structure of neutron-rich isotopes 129Sn and 133Sn . . . . . 111
Spectroscopic studies of 116,118,120Sn through thermal neutron induced reactions using FIPPS ...... 112
xi Negative-ion surface production in hydrogen low-pressure plasmas ...... 113
On developing an open access first year physics textbook and other free things . . . . . 114
92 - PICO-40l Installation and Commissioning ...... 114
Laser Wakefield Driven X‐ray Sources in Canada: Future perspectives for non-destructive imaging and Global Food Security ...... 115
Tilting Transition in a Liquid Crystalline Polymer Brush ...... 115
Using the profile-likelihood method to search for dark matter in DEAP-3600 ...... 116
18 - Improvement of the Efficiency and Beam Quality of the TRIUMF Charge State Booster ...... 116
72 - Scintillating Bubble Chamber for Detecting Dark Matter ...... 117
Lost horizons: modelling the formation and evaporation of non-singular black holes. . . 117
Symmetry protected Luttinger liquids on the surface of Quantum Hall Nematics. . . . . 117
Precise Measurement of Rare Pion Decay ...... 118
The nuclear structure of 118Sn studied through the β-decay of 118In at TRIUMF . . . . . 118
Search for Dark Matter with NEWS-G experiment ...... 119
Investigation of radiation damage centers in highly isotopically enriched silicon-28 as po- tential single spin qubits accessible via spin/photon coupling ...... 119
Evolution of the N=82 Neutron-Deficient Shell Closure and Pushing Toward the Proton Drip-Line at TITAN ...... 120
How is silicon-28 a ”semiconductor vacuum”? / « Comment le silicium 28 est-il un « vide semi-conducteur ? » ...... 121
Masses of neutron-rich Ga isotopes for the formation of the 1st r-process abundance peak in neutron star merger ...... 122
Charge and spin-specific local integrals of motion in a disordered Hubbard model . . . . 123
Impact of the Canadian Neutron Beam Centre ...... 124
ComPAIR: A Flexible Teaching Technology for Facilitating Peer Evaluation ...... 124
Epitaxial Growth of Single Crystal Noble Metals for Plasmonic and Nanophotonic Applica- tions ...... 124
Current dissipation of ultracold atoms in an optical lattice ...... 125
44 - Sum rule for transport dynamics of ultracold atoms in an optical lattice ...... 125
Optical control of valley pseudospin in 2D semiconductors ...... 126
38 - Radio-frequency spectroscopy of one-dimensional Fermi gases near a p-wave Feshbach resonance ...... 127
xii Geometric Magnetic Frustration in Correlated Metallic Systems ...... 127
Photoinduced gap renormalization and many-body recombination in insulating cuprates 128
11 - Open Textbooks - we have led the horses to water – now what? ...... 129
Optical second harmonic susceptibility in the Weyl semimetal tungsten telluride . . . . . 130
31 - Thermal Conductances of Silicon Phononic Crystals by Molecular Dynamics . . . . 130
Magnetotransport in topological metals ...... 131
Probing Dark Energy with CHIME ...... 131
Understanding identity and social networks among women in graduate physics education 132
Production of Ultracold Lithium Triplet Dimers by STIRAP ...... 132
Vector beams, high harmonic generation and sub-focal spot coherent control ...... 133
53 - Production of Ultracold Lithium Triplet Dimers by STIRAP ...... 133
Ultrafast terahertz microscopy: from near fields to single atoms ...... 134
Random phase approximation and renormalized Gaussian chain for charged hetero-biopolymers and their sequence-specific phase behavior ...... 135
Near-Unitary Spin Squeezing with Ytterbium ...... 135
78 - LED-Based Detector Calibration Studies for the SuperCDMS SNOLAB Experiment . 136
Dark Absorption in SuperCDMS Soudan ...... 136
Measurements of proton-carbon differential cross-sections at 20, 30, and 120 GeV/c in EM- PHATIC experiment ...... 137
A new measurement of the permanent electric dipole moment of 129-Xe using 3-He comag- netometry and SQUID detection ...... 137
61 - First high voltage breakdown measurements in a test setup for the TUCAN neutron EDM experiment ...... 138
Stable longitudinal spin domains in a nondegenerate ultracold gas ...... 138
45 - Modifying spin transport in a one-dimensional nondegenerate ultracold gas . . . . . 138
7 - Beam physics models of the TRIUMF linear accelerators for advanced beam tuning methods ...... 139
Coulombic contribution to angular momentum flux in general relativity ...... 139
Compton Scattering and the Nucleon Polarizabilities ...... 140
64 - The Mont Blanc neutrino burst from Supernova 1987A ...... 140
Diffusion-controlled drug delivery: Avoiding pitfalls when using Lattice Monte Carlo(LMC) simulations ...... 141
xiii Quantum magnetism in honeycomb lattice materials ...... 141
Characterization and development of a new SiPM with high VUV sensitivity for the nEXO Experiment ...... 141
Ionization yield measurements for NEWS-G ...... 142
91 - Expected Neutron Background for the PICO-500 Detector with Geant4 Simulations . 142
New discoveries and observations of universal physics in collisions ...... 143
Status of the SNO+ experiment ...... 144
Geometric Inflation ...... 144
Could GaAs (001) Know What Bacterium Has Bitten It? ...... 144
Configuration mixing investigation in germanium isotopes through measurement ofE0 transition strengths ...... 145
Quantum state dependent chemistry of ultra-cold 6Li2 dimers ...... 146
54 - Quantum state dependent chemistry of ultra-cold 6Li2 dimers ...... 146
39 - Sorting of Free-Space Spatial Modes of Light with Integrated Optics ...... 147
WITHDRAWN - Magnetometry for Gravitational Measurements of Antihydrogen with ALPHA-g ...... 147
Ignite wonder, empower dreams, explode soda ...... 148
Teaching with Neutrons: Labs, Courses, and Student Research Projects at the McMaster Nuclear Reactor ...... 148
Dynamical tunnelling in the quantum kicked top ...... 148
Beta decay spectroscopy of Europium-160 ...... 149
Neutron Scattering at the McMaster Nuclear Reactor: Past, Present and Future ...... 149
Potential mapping in GaN nanowire p-n junctions via off-axis electron holography . . . 150
Neutrons and X-Rays for Health and Disease ...... 150
Imaging the In-Plane Anisotropy and Lattice Defects of ReS2 Using Scanning Tunneling Microscopy ...... 151
Self-regulating mechanisms of bi-directional transport through the Nuclear Pore Complex ...... 151
Calibration and Physics Outlook of PICO-40L ...... 152
Evaluation of a Science & Math Peer Tutoring Program ...... 152
Fabricating van der Waals heterostructures ...... 153
High Precision Mass Spectrometry for Fundamental Tests of the Weak Interaction . . . . 153
xiv Proteins drilling holes in lipid membranes: The influence of the membrane physical param- eters ...... 154
Implementing an ancillary detector for DESCANT to determine neutron energies . . . . 154
WITHDRAWN - Laser spectroscopy of the g6Φ − X4∆ electronic transition of iron mon- odeuteride, FeD ...... 155
WITHDRAWN - Identification of the A1Π and a3Π electronic states of magnesium monosulphide, MgS ...... 155
79 - WITHDRAWN - First Implementation of CsI(Tl) Pulse Shape Discrimination at a B- Factory Experiment for Improving Hadronic vs Electromagnetic Shower Identification ...... 156
Modern-day precision mass measurements and the astrophysical r process ...... 156
Anomalous, caged and obstructed diffusion as seen through the lens of inverted variable- lengthscale fluorescence correlation spectroscopy ...... 157
Advances in Microwave Spectroscopy of Antihydrogen ...... 157
55 - Development of a Novel 650 MHz Resonator for Microwave Spectroscopy of Antihy- drogen ...... 158
EXO-200 Results ...... 159
Assembly and Characterization of MoS2/HBN heterostructures for Opto-electronic devices ...... 159
Active dopant and associated diffusion potential mapping in Silicon nanowires . . . . . 160
Tracking the Phase Transition in VO2 using High Harmonic Spectroscopy ...... 160
A measurement of the Lamb shift in atomic hydrogen and its implication for the proton size puzzle ...... 161
56 - Ultrahigh-Precision Measurement of the n = 2 Triplet P Fine Structure of Atomic He- lium Using Frequency-Offset Separated Oscillatory Fields ...... 161
65 - Low Background Measurement Capabilities At SNOLAB ...... 162
Towards measuring atomic parity violation effects in francium ...... 162
46 - EDM3: Measuring the electron electric dipole moment using polar molecules embedded in solid argon ...... 163
Commissioning of a Plasma Ion Source Using Monte Carlo Optimisation Methods . . . . 163
Continuing Prospects of the SNO+ Calibration Program ...... 164
Rayleigh Scattering Formulation of the Tune-out Wavelength: Theory and Application to Metastable Helium ...... 164
Machine learning techniques for event reconstruction in water Cherenkov detectors . . 165
Developments in Compression of Magnetized Plasmas ...... 165
xv Study of the 28Mg(t,30Mg)p reaction to investigate nuclear shell evolution at the boundary of the N=20 Island of Inversion ...... 165
General Fusion’s Approach to Magnetized Target Fusion ...... 166
The HALO-1kT Supernova Neutrino Detector ...... 167
15 - General Fusion Overview ...... 167
16 - Fast Neutron Diagnostics on MTF Compression Experiments ...... 168
The nucleation of ZnO nanowires on sputter deposited metal substrates ...... 168
Surface-Plasmon Polaritons at Lossy Curved Interfaces ...... 169
Detailed Spectroscopy of Doubly-magic 132Sn with GRIFFIN ...... 169
Should Gauss’s Law Be Taught in First Year? ...... 170
New Strategies for Single Crystal Plasmonic Nanostructures and Plasmon-based Solar En- ergy Harvesting ...... 170
Measurement of the Stark Shift of the 7s-8s Transition in Francium ...... 170
Latest results from EXO-200 and status of nEXO ...... 171
19 -Pulsed-Target Magnetron-Enhanced ICP Plasma System ...... 171
Modern Applications of Monte Carlo Simulations in External Beam Radiation Therapy . 172
Commissioning the Radial Time Projection Chamber for the ALPHA-g antimatter gravity experiment ...... 172
The effect of hyper-resistivity on nonlinear resistive tearing modes ...... 173
Producing ultracold neutrons with a spallation source and superfluid helium ...... 173
Using PENTrack to study systematics in the neutron electric dipole moment measurement at TRIUMF ...... 174
Boundary conditions, zero modes, and spacetime entropy ...... 174
Gamma Ray Spectroscopy of 34Ar Using Fusion Evaporation ...... 174
Harnessing amplified ultrafast laser pulses for studying and controlling quantum materials ...... 175
A linear quadrupole ion trap for barium tagging in nEXO ...... 176
Muon as a unique probe in condensed matter physics ...... 176
57 - The 5s→6s Stark shift measured via two-photon spectroscopy in laser-trapped rubid- ium ...... 177
Characterization of Angular Dependency of Photon Detection Efficiency of VUV Silicon Photo-Multipliers ...... 177
8 - Thin Film Characterization ...... 178
xvi 13 - How the UBC Young Women for Science inspires students to study STEM ...... 178
Direct Measurement of the Dynamic Modulus of Gellan Gum Micro-Capsules ...... 179
Optical microscopy with kinky photons ...... 179
WITHDRAWN - 2-Dimensional Vibrational Sum Frequency Generation Spectroscopy of Organic Monolayers ...... 180
Beta Decay of 80,82-Ga with GRIFFIN and Shape Coexistence in 80,82-Ge ...... 180
Imaging the brain at high spatiotemporal resolution / Imagerie cérébrale à haute résolution spatiotemporelle ...... 181
Global warming: A question of priorities / Réchauffement climatique : une question de priorités ...... 182
Computer simulations of biological membrane models: lateral structure and lipid-protein interactions ...... 183
In-Vivo Solid-State NMR for the Study of Biological Membranes ...... 183
Changes in lipid membrane may trigger amyloid toxicity in Alzheimer’s disease. . . . . 183
Molecular composition of the mitochondrial permeability transition pore...... 184
From Nonlinear Optics to High-Intensity Laser Physics / De l’optique non linéaire à la physique des lasers à haute intensité ...... 185
Dying Escherichia coli cells absorb antimicrobial peptides, enhancing the survivability of the cell culture ...... 185
Droplets as model systems for investigating 2D crystals, glasses, and the growth dynamics of granular aggregates ...... 186
Finding Myelin: Quantum mechanics in cow brains? ...... 186
New Frontiers in Cosmology / Nouvelles frontières en cosmologie ...... 187
Atomic-scale dynamics of collective charge and spin excitations ...... 187
Anti-chiral order and damped spin waves in the topological semi-metal Mn3Ge . . . . . 188
Hydride Superconductors, a path to room temperature superconductivity ...... 188
From Quantum Spin Ice to Ordered Spin Ice in the Pyrochlore Tb2Ge2O7 ...... 189
Magnetic Excitation Spectrum of a Coulomb Spin Liquid ...... 189
Quantum magnetism on a chip ...... 190
Influence of Rashba effect on carrier kinetics in hybrid perovskites ...... 190
From Mott to not: phenomenology of overdoped cuprates ...... 191
Strange metallic transport in the doped Hubbard model ...... 191
Exploring the pseudogap critical point of cuprate superconductors ...... 191
xvii When Molecules Met 2D Materials: Hybrid van der Waals Heterostructures ...... 192
The magnon-mediated attraction between two holes doped in a CuO2 layer ...... 192
Ab initio exploration of 12C ...... 193
Stress in a Polymer Brush ...... 193
Non-equilibrium response of a strongly coupled rotary motor ...... 193
Spacetime thermodynamics and Weyl rescaling ...... 194
Investigation of the A=7 systems within the No-Core Shell Model with Continuum . . . 194
26 - Etude des propriétés thermochromes des couches minces de VO2 ...... 195
48 - Building a Portable, Cold-Atom Pressure Standard ...... 195
40 - Propriétés optiques et électriques des couches minces du VO2 ...... 196
The Field-Reversed Configuration as a Practical Fusion Reactor Core ...... 196
20 - Mitigation of the Rotational Instability of the Field-Reversed Configuration via Edge- Biasing ...... 197
Nuclear kinetic density from ab initio theory ...... 197
EDMs and Dark Sectors ...... 198
Structure of 188Hg From Gamma-ray Spectroscopy With GRIFFIN ...... 198
The PICO Experiment ...... 199
Creative Chemistry and Cyclotrons: Training students and expanding the toolbox of PET radionuclides ...... 199
Dark Matter Searches with VERITAS ...... 200
Decay studies using the GRIFFIN Spectrometer at TRIUMF-ISAC ...... 200
Cuscuton Bounce ...... 200
CNT-based composite to eliminate Chemical shift error in simultaneous PET/MRI . . . . 201
Canada’s DRAGON ...... 201
Better motors, generators and transformers for electrical power ...... 202
Gamma-Ray Spectroscopy at the Limits ...... 202
The CANREB Project for Charge State Breeding at TRIUMF ...... 203
Spin-dependent superfluidity in ultracold BECs ...... 203
Recent progress on Strangeness Nuclear Physics at J-PARC ...... 203
86 - Numerical Simulation of Biomagnetic Field from Somatosensory Evoked Response . 204
xviii Accelerated Diffusion-Weighted Hyperpolarized 129Xe Gas Lung MRI ...... 204
Two-major shell-model effective Hamiltonian from in-medium similarity renormalization group approach ...... 205
Positron emission tomography (PET) contributions to a better understanding of brain func- tion ...... 206
41 - Controlled enantioselective orientation of chiral molecules with an optical centrifuge 206
Optimization of nanoparticle transport using monolayer and multilayer cell models . . . 207 questions ...... 207
Operational Principles for the Dynamics of a Rolling Motor ...... 207
58 - Dueling Dynamical Backaction in a Cryogenic Optomechanical Cavity ...... 208
66 - Calibrating an ultra-low bacground detector: DEAP rising to the challenges. . . . . 208
Investigating shell evolution in neutron-rich Kr isotopes with transfer reactions . . . . . 209
Monitoring and Optimizing Beer Flavour and Quality Using Raman Spectroscopy . . . . 209
Photoconductivity of SnIP Semiconducting Inorganic Double Helices ...... 210
47 - A Slow Optical Centrifuge ...... 210
4 - Plasmonic All-Optical Switching by Metamaterial-Dielectric Mach-Zehnder Interferom- eter ...... 211
The optical properties of aging and diseased tissue interfaces: what are your gumsand bones telling you? ...... 211
Discovery and Characterization of New Frustrated Magnetic Systems ...... 212
73 - Search for SUSY with missing transverse momentum and multiple b-jets ...... 213
59 - Carbon disulfide superrotors in helium nanodroplets ...... 213
Quantum simulation of 2D and 3D spin systems in a linear chain of trapped ions . . . . 214
Overview of Dark Matter Searches by the ATLAS Experiment ...... 214
Characterization of the Si:Se+ spin-photon interface ...... 215
Remarkable linewidth improvements for well-known radiation damage centres in highly enriched 28Si ...... 215
Universality of Spreading Processes with Spontaneous Activity ...... 216
Size bistability in multiferroic nanoparticles ...... 217
Spacetime from bits and cosmology from black holes ...... 217
New thermodynamic identities for five-dimensional black holes ...... 217
Intracellular Retention and Redistribution of Gold Nanoparticles with Docetaxel . . . . . 218
xix TO BE REPLACED - A new semiclassical picture of vacuum decay ...... 218
Entanglement and the Infrared ...... 219
WITHDRAWN - Fiducial Differential Cross Section Measurements in the HZZ4l Channel with the ATLAS Detector ...... 219
5 - Can Operating Conditions affect CANDU® Pressure Tube Resistivity? ...... 219
Quantum optics approaches for quantum networks and other applications ...... 220
Optimization of Dental Cone Beam Computed Tomography for Planning Dental Implant Treatments ...... 221
Polymer dynamics in confined flows ...... 221
60 - Fiber-based nanoprobe for the detection of chemicals ...... 222
Optical control of fast and processive engineered myosins in vitro and in living cells . . 222
Road-map to use of gold nanoparticles in cancer radiotherapy ...... 223
Investigation of Multi-frequency Raman Generated Spectra ...... 223
Low-frequency quantum beats in three-level systems ...... 224
Plasma Treatment of Wood Surfaces ...... 224
Light-cones and quantum caustics in quenched spin chains ...... 225
42 - Adsorption of organic molecules on solid surfaces using surfactants: A Molecular dy- namics study ...... 225
85 - Modelling emission of acoustic energy during bubble expansion in PICO bubble cham- bers ...... 225
Enhanced gel formation in binary mixtures of nanocolloids with tunable short-range at- traction ...... 226
Qubits as edge state detectors: illustration using the SSH model ...... 226
49 - Development of a gold nanoparticle sensor to detect environmental DNA of invasive fish species in the Great Lakes ...... 227
Completion of a Prototype Cryogenic Energy Storage and Deep Mine Chilling Co-generation System, Construction of Prototype and Results from Testing...... 227
12 - Selective Assessment in Introductory Physics Labatorials ...... 228
Detecting Lorentz invariance violations with a quantum cavity ...... 228
33 - Optical feedback tweezers ...... 228
Connecting Superconductivity and Quantum Criticality with the High-Field Hall Effect in a Strange Metal ...... 229
Breast radiotherapy in a single day: innovation advancing clinical care ...... 229
xx Poster Slam Talks, click to see list; abstracts can be seen in Tues. PPD Poster Session . . 230
“Why we can’t wait: The urgency of diversity and decoloniality in our times” / « Pourquoi ne peut-on attendre? : L’urgence de la diversité et de la décolonisation à notre époque » ...... 230
NSERC’s Dimensions: Equity, Diversity, and Inclusion Canada and Other EDI Initiatives 231
67 - Meson-Hybrid Mixing in Vector and Axial Vector Charmonium ...... 231
43 - A Stern-Gerlach separator of chiral enantiomers based on the Casimir-Polder potential ...... 232
23 - Discrete Self-Similar Solutions in Bianchi-IX Spacetimes ...... 232
68 - K+ to pi+ nu nubar - First result from the NA62 experiment ...... 232
80 - The Axion Quark Nugget Dark Matter Model: Size Distribution and Survival Pattern 233
90 - Atmospheric plume dynamics of a picosecond infrared laser with applications in surgery and biodiagnostics with mass spectrometry ...... 233
69 - Quasi-Monoenergetic Neutron Beams for Characterizing Dark Matter Detectors . . 234
Deep Generative Models and Applications to Physics ...... 234
Quantum computing with the D-Wave processor ...... 235
Commercial Career Physicists ...... 235
Honeywell ...... 235
MDA / MAXAR ...... 235
MDA / MAXAR ...... 236
D-Wave ...... 236
Broadcom ...... 236
Insight Data Science (Intro) ...... 236
Honeywell ...... 237
D-Wave ...... 237
Broadcom ...... 237
Honeywell ...... 237
D-Wave ...... 237
MDA / MAXAR ...... 237
Honeywell ...... 238
CanMind ...... 238
xxi 81 - Measurement of IceCube Dom Performance Using Atmospheric Muons ...... 238
82 - Search for Neutrino Trident Events in IceCube ...... 238
34 - Dynamics verses thermodynamics in two-step nucleation ...... 239
Physics for Novice and Expert / La physique pour novices et experts ...... 239
Probing Superconductivity and Magnetism in Quantum Materials with Muons / L’exploration de la supraconductivité et du magnétisme des matériaux quantiques contenant des muons ...... 240
Nonperturbative dynamics of 2+1d Gauge Theories / Dynamique non perturbatrice des théories de jauge 2+1d ...... 241
Diamond nanophotonics: using light to talk to phonons and spins / Dispositifs nanopho- toniques à diamants faisant interagir la lumière sur les phonons et les spins . . . . . 241
A Journey from Superconductivity to Teaching Reasoning in First-Year Labs / De la quête de la supraconductivité à l’enseignement du raisonnement en première année de labo- ratoire ...... 242
Weakly probing the universe across nine decades in energy / Exploration sommaire de l’Univers sur neuf ordres de grandeur en énergie ...... 242
88 - Multi-seeded MD simulation to effectively sample the conformation space of short peptide ...... 243
An Integrative, Student-Centered Approach to Teaching Today’s Physics and Astronomy Students ...... 243
So They Think They Hate Physics … Building Confidence in 1st Year Science Students . . 244
Implementing Innovation in Physics Teaching and Learning ...... 244
Extended Lunch Panel | panneau déjeuner prolongé ...... 244
Insight Data Science ...... 245
Director of Professional Affairs, CAP ...... 245
A critical analysis of the CMB: constraining CMB physics with peaks, valleys, and saddles 245
89 - Mechanical, chemical, structural, and radiological changes in pigeon bone, associated with the dietary intake of nickel recovery slag as a grit source...... 245
PLACEHOLDER - Insight Data Talk ...... 246
PLACEHOLDER - Industrial Problem Solving Workshop Talk ...... 246
IPP Director’s Report & Council Election Results ...... 246
European PP Strategy Update ...... 246
Canadian Particle Physics Computing Issues ...... 247
McDonald Institute Report ...... 247
xxii EXO-200 and nEXO ...... 247
Applications - Single photo-detector landscape in Canada ...... 247
Development - 3DdSiPM ...... 247
Applications - nEXO, LoLX and liquid Xenon ...... 247
Development - development of VUV light detection solutions ...... 248
Applications - liquid Argon ...... 248
Applications - Bubble chamber ...... 248
Development - Hybrid photo-detectors ...... 248
Ocean network ...... 248
Water Cerenkov for long baseline neutrino oscillation ...... 249
Development - mPMT ...... 249
Commercial opportunities ...... 249
T2K and HyperK ...... 249
NA62 ...... 249
Belle II ...... 249
PICO ...... 249
ATLAS ...... 250
SuperCDMS ...... 250
IceCube ...... 250
SNO+ ...... 250
DEAP ...... 250 test ...... 250
93 - Properties of Retinal Amyloid Deposits in Association with Alzheimer’s Disease . . 250
Industrial Problem Solving Workshops ...... 251
Measuring antimatter gravity in the ALPHA-g magnetic trap ...... 252
President & CEO, TRIUMF Innovations ...... 252
NSERC SAPES Chair Report ...... 252
News from CFI ...... 252
TRIUMF Director Report ...... 253
SNOLab Director Report ...... 253
xxiii Close ...... 253
xxiv 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
M-HERZ Herzberg Memorial Public Lecture | Conférence publique commémorative Herzberg - M. Prakash, Stanford / 2380
Frugal Science in the Age of Curiosity / La science frugale à l’ère de la curiosité
Author: Manu Prakash1
1 Stanford University
Corresponding Author: [email protected]
Science faces an accessibility challenge. Although information/knowledge is fast becoming available to everyone around the world, the experience of science is significantly limited. One approach to solving this challenge is to democratize access to scientific tools. Manu Prakash believes this can be achieved via “Frugal science”; a philosophy that inspires design, development, and deployment of ultra-affordable yet powerful scientific tools for the masses. Using examples from his ownwork (Foldscope: one-dollar origami microscope, Paperfuge: a twenty-cent high-speed centrifuge), Dr. Prakash will describe the process of identifying challenges, designing solutions, and deploying these tools globally to enable open ended scientific curiosity/inquiries in communities around the world. By connecting the dots between science education, global health and environmental monitoring, he will explore the role of “simple” tools in advancing access to better human and planetary health ina resource limited world.
La science est confrontée au défi de l’accessibilité. Bien que l’information et la connaissance devien- nent rapidement disponibles à tout dans le monde, l’expérience de la science est considérablement limitée. Une approche visant à résoudre ce défi est la démocratisation de l’accès à des outils sci- entifiques. Manu Prakash croit que cela peut être atteint par le biais de la « science frugale»;une philosophie qui sous-tend à la conception, au développement et au déploiement d’outils scientifiques à la fois extrêmement abordables et puissants pour les masses. En utilisant des exemples provenant de son propre travail (le Foldscope : un microscope en origami à un dollar et le Paperfuge : une centrifugeuse à haute vitesse à vingt-cinq cents), le Dr Prakash décrira le processus d’identification des défis, la conception de solutions et le déploiement de ces outils à l’échelle mondiale afindefaire naître la curiosité et des recherches scientifiques ouvertes dans les communautés du monde entier. En faisant le lien entre l’éducation scientifique, la santé mondiale et la surveillance environnemen- tale, il explorera le rôle des outils « simples » pour faciliter l’accès à une meilleure santé humaine et planétaire dans un monde aux ressources limitées.
W1-6 Tests of quark and lepton flavour (PPD) | Tests de saveurs de quarks et leptons (PPD) / 2381
R(D(∗)) measurement at the Belle II Detector
Author: Hannah Wakeling1
1 Belle II Group at McGill University
Corresponding Author: [email protected]
The Belle II detector is a significant upgrade of the Belle detector and will be a competitive, per- haps unique, environment in which to study rare B decays with missing energy to a sensitivity that would exhibit indirect New Physics effects. From a B-B¯ meson pair that has been produced in the SuperKEKB energy-asysmmetric e+e− collider and B-factory, one B meson can be fully recon- structed through powerful B-tagging, which in turn provides strong constraints for the other B meson. The design luminosity of SuperKEKB is 8 × 1035 cm−2 s−1, where the Belle II experiment − aims to record 50 ab 1 of data, a factor of 50 more than the original Belle experiment. This is an ideal environment in which rare decays with missing energy can be measured. The decay B → D(∗)τν
Page 1 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
will be examined with the prospects of the R(D(∗)) measurements, in which we anticipate a result − of unprecedented precision with as little as 5 ab 1 of data.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2382
WITHDRAWN- Symmetry restoration in mixed-spin paired heavy nuclei
Authors: Ermal Rrapaj1; Augusto O. Macchiavelli2; Alexandros Gezerlis3
1 University of California, Berkeley - University of Minnesota 2 Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley 3 Physics Department, University of Guelph
Corresponding Authors: [email protected], [email protected], [email protected]
The nature of the nuclear pairing condensates in heavy nuclei, specifically neutron-proton (spin- triplet), versus identical-particle (spin-singlet) pairing has been an active area of research for quite some time. In this work, we probe three candidates that should display spin-triplet, spin-singlet, and mixed- spin pairing. Using theoretical approaches such as the gradient method and symmetry restoration techniques, we find the ground state of these nuclei in Hartree-Fock-Bogoliubov theory and compute ground state to ground state pair-transfer amplitudes to neighboring isotopes while simultaneously projecting to specific particle number and nuclear spin values. We identify specific reactions for future experimental research that could shed light on spin-triplet and mixed-spin pairing.
W2-2 Quantum Information (DAMOPC/DTP) | Information quantique (DPAMPC/DPT) / 2383
Quantum cryptography in realistic conditions with structured pho- tons
Author: Alicia Sit1 Co-author: Ebrahim Karimi 2
1 Department of Physics, University of Ottawa, Advanced Research Complex 2 University of Ottawa
Corresponding Authors: [email protected], [email protected]
Quantum Key Distribution (QKD) is a promising quantum cryptographic solution to maintain infor- mation security after the advent of quantum computers. QKD makes use of quantum mechanical properties to construct information-theoretically secure protocols for the transmission of an encryp- tion key between two separated parties, colloquially named Alice and Bob. In the last decade, there have been many efforts across the world to bring QKD schemes and protocols to a technologically feasible level for use beyond the research laboratory, with major advances in free-space and optical fiber channels. A major challenge for these systems when implemented in realistic conditions, e.g. outside laboratories, is the disruptive/degrading effect of environmental factors, such as turbulence or background noise, on the transmitted information. Here, we outline the recent research conducted in Ottawa, Canada, which studies the feasibility of performing QKD in free-space and underwater quantum channels subject to uncontrolled environmental factors. In particular, we study the effect of turbulence on transmitted quantum bit error rates (QBER) in these channels when encoding with the spin and orbital angular momentum degrees of freedom – so-called structured photons – demon- strating the feasibility of high-dimensional QKD schemes. These high-dimensional protocols will enable the transmission of more information, more securely, than conventionally possible.
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R1-4 Molecular sciences: outreach, teaching and research (DPE/DAMOPC) | Sciences molécu- laires: rayonnement, enseignement et recherche (DEP/DPAMPC) / 2384
To Flip or not to Flip: Video Experiments in Physics Teacher Ed- ucation
Author: Marina Milner-Bolotin1
1 The University of British Columbia
Corresponding Author: [email protected]
Secondary physics teachers in British Columbia are faced with increasing demands of the new sci- ence curriculum, which in addition to the traditional content knowledge and skills emphasizes big science ideas, core skills and competencies, and science communication. At the same time, modern schools want teachers to be skilled in creative use of technology in order to engage 21st century students. Using technology to encourage students to become active physics learners is one of the biggest challenges of modern secondary science teachers. Science experiments are essential for help- ing physics teachers achieve this goal in their face-to-face or virtual classrooms. Thus, future physics teachers have to be prepared to use technology to teach physics in a captivating and interactive way. This is what my research team at the University of British Columbia is trying to achieve inour physics methods courses. In this presentation, I will demonstrate how my research team has incor- porated modern video technologies in science methods courses in order to support future physics teachers in conducting effective and simple science demonstrations and experiments in their classes. In addition, we use this technology to prepare future teachers to teaching in a flipped classroom or even virtual learning environments. By learning how to design educational physics videos depict- ing these demonstrations future teachers improve their knowledge of physics and physics pedagogy, while learning about new technology. So while the answer to the “To flip or not to flip?” question depends on many factors, future teachers should be prepared to engage modern students using all available everyday life tools, including video technology.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2385
WITHDRAWN - Estimation of interdiffusion variables for tung- sten - glassy carbon couples
Authors: Audu Innocent1; Eric Njoroge 1; Johan Malherbe2; Thulani Hlatshwayo1
1 Department of Physics, University of Pretoria, Hatfield 2 Department of Physics, University of Pretoria
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Estimation of interdiffusion variables for tungsten - glassy carbon couples A.J. Innocent*, T.T. Hlatshwayo, E.G. Njoroge and J.B. Malherbe Department of Physics, University of Pretoria, Pretoria, 0002, South Africa Corresponding author E-mail address: [email protected] ABSTRACT Thin films have a wide applications in both electronic and nuclear industries. Many industrial pro- cesses, especially in the nuclear industry where the tasks of prolonging the lifespan of machine parts are of crucial interest, the roles of thin film in tribology are being exploited as superior alternative to conventional lubrication in liquid-base systems. In this study, thin films of tungsten (W) were deposited by DC magnetron sputtering on glassy carbon (GC) substrates. The as-deposited samples were annealed under vacuum at temperatures ranging from 200 to 1000 oC at various annealing durations. The mixing between W and GC atoms was investigated by Rutherford backscattering
Page 3 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
spectroscopy (RBS). RUMP and Data furnace programs were used to analyze the RBS spectra which revealed the thickness of W thin film deposited, atomic composition of deposited layer and aswell as the reaction zones. Depth profiles obtained from the simulated results were used to estimate the interdiffusion coefficients of W–GC couples. From the interdiffusion coefficients obtained atthean- nealing temperatures between 700 and 1000 oC, where the interaction zones were well pronounced, the activation energy Ea and the pre-exponential factor Do were evaluated for the tungsten-glassy carbon diffusion couples; Ea is estimated to be 115 kJ/mol. while Do has a value of 1.1 x 10 ^(-11) m2/s. Results of XRD, AFM, SEM and Raman complement each other well. Keywords: tungsten, glassy carbon, interdiffusion, data furnace, RBS, RUMP
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2386
35 - Plasmon-Enhanced Stimulated Raman Spectroscopy with Low- Power CW Lasers
Authors: Yashar Esfahani Monfared1; Kevin Hewitt1; Travis Shaffer2; Sanjiv Sam Gambhir2
1 Dalhousie University 2 Stanford University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
We present a successful combination of stimulated Raman spectroscopy (SRS) and surface-enhanced Raman scattering (SERS) using low-power cw laser sources and gold/silica nano-particles withem- bedded reporter molecules. We demonstrate that cw surface-enhanced stimulated Raman spec- troscopy (cwSESRS) can be used to detect a Raman signal in samples with pico-molar or low nano- molar concentrations via a nano-particle enhancement. We report the preparation method for sam- ples and illustrate how Raman spectra generated from our experiment matches the conventional Raman spectra of these samples. We also investigate the effect of source power, polarization and sample concentration on the cwSESRS signal. The realization of cwSESRS with low-cost cw sources, and pump and Stokes powers as low as 34 mW and 440 mW, leads to opportunities for a wider range of Raman spectroscopy applications especially in clinical research.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2387
Modeling the slow cytotoxic swelling of dystrophic muscle fibers
Authors: Bela Joos1; Joshua Wheeler1; Catherine E Morris2
1 University of Ottawa 2 Ottawa Hospital Research Institute
Corresponding Authors: [email protected], [email protected]
In Duchenne muscular dystrophy (MD) patients, muscle fiber Na+-loading is linked to cytotoxic swelling. Quiescent fibers move away from their resting membrane potential Vrest (and towards Donnan equilibrium) due to concurrently open Na+ and Cl- conductances that together underlie the swelling and depolarization. Since a chloride conductance (ClC-1) underlies healthy Vrest in fibers, whatever underlies the Na+-loading is the pathologic conductance. Indeed, increased Na/K pump activity counteracts swelling and promotes repolarization (see review by Morris (Curr Topics Memb 81, 2018)). The classic animal model for Duchenne MD is the dystrophin-less mouse, mdx.
Page 4 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Wild-type muscle fibers are better able to resist mechanically-induced (pipette aspiration) sarcolem- mal blebbing than mdx fibers and they more effectively use caveolar tension buffering to maintain sarcolemmal integrity. In 3-day survival experiments, isolated fiber survival is markedly worse in mdx than in wild-type. The Na+ channel blocker Tetrodotoxin provides full protection formdx fibers, indicating that the mdx fibers have “leaky” Nav1.4 channels. We postulate that itisspecif- ically the Nav1.4 channels resident in bleb-damaged areas of dystrophic sarcolemma that would exhibit left-shifted operation. The result – an increased gNa(V) window conductance at abnormally hyperpolarized voltages – would continually stress ion homeostatic processes, making it likely that cytotoxic swelling would eventually become evident. We built an MD muscle cell model including ion concentrations, conductances, pumps, volume, membrane potential and tensions. Damage is represented by a coupled left shift (CLS) of the activation and inactivation kinetics of afractionof the Nav channels. The model predicts cytotoxic swelling with anoxia (no pump activity). Itshows the tolerance of the muscle cell to damage, with no swelling until a critical state. It explains also how increased pump activity can keep the swelling under control.
W1-4 Advances in Nuclear and Particle Theory (DTP/PPD/DNP) | Progrès en théorie nucléaire et théorie des particules (DPT/PPD/DPN) / 2388
Probing the Strangeonium Hybrid Content of the Y(2175) Using Gaussian Sum-Rules
Authors: Derek Harnett1; Jason Ho2; Ryan BergNone; Tom Steele3; Wei Chen4
1 University of the Fraser Valley 2 University of Saskatchewan 3 U of Saskatchewan 4 Sun Yat-sen University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
The Y(2175) resonance was first observed in an initial state radiation process by the BaBar Collabo- ration. It was later confirmed by the BES, Belle, and BESIII collaborations. A conventional strangeo- nium meson interpretation of the Y(2175) is disfavoured due to the resonance’s relatively narrow width and unexpected decay patterns. As such, it may be an outside-the-quark-model hadron, e.g., a hybrid, tetraquark, and/or meson molecule. We use Gaussian sum-rules—a variant of QCD sum- rules well-suited to studying multi-resonance models—to investigate possible strangeonium hybrid content of the Y(2175).
W2-3 Molecular Motors (DPMB) | Moteurs moléculaires (DPMB) / 2389
Reducing dissipation in far-from-equilibrium biomolecular pro- cesses
Authors: Sara Tafoya1; Steven J. Large2; Shixin Liu3; Carlos J. Bustamante4; David A. Sivak5
1 Biophysics Graduate Group, University of California, Berkeley 2 Dept. of Physics, Simon Fraser University 3 Rockefeller University 4 Dept. of Physics, University of California, Berkeley 5 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
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Biomolecular machines are central actors in a myriad of major cell biological process. It seems plau- sible that evolution has sculpted these machines to efficiently transduce free energy (thus reducing dissipation) in their natural contexts, where stochastic fluctuations are large, nonequilibrium driv- ing forces are strong, and biological imperatives require rapid turnover. But what are the physical limits on such nonequilibrium efficiency, and what machine designs actually achieve these limits? In this talk, I discuss a theoretical framework predicting how to rapidly and efficiently drive such noisy systems from one state to another, and describe experiments demonstrating the utility of this framework for reducing dissipation when rapidly unfolding and refolding the ‘hydrogen atom’ of biophysics, a single DNA hairpin.
DPE Poster Session & Student Poster Competition Finals (5) | Session d’affiches DEP et finales du concours d’affiches étudiantes (5) / 2390
9 - Game of Hadrons
Author: Kevin Douglas1
1 Okanagan College
Corresponding Author: [email protected]
In an effort to help students learn about the internal composition of various mesons andbaryons, a simple game has been developed, inspired by the Eightfold Way organizational ideas of Murray Gell-Mann. In the game, two diagrams of mesons and two diagrams of baryons are created, with charge and strangeness as the principle axes. Students draw from four colour-coded sets of cards - each colour corresponds to one of the diagrams. Based on the particle symbol and quark/antiquark arrangements on the card, the student must place the particle in the correct position on the appro- priate diagram.
T2-2 Plasmas at Surfaces (DPP) | Plasmas sur des surfaces (DPP) / 2391
About the definition of a ”local” temperature around a spacecraft in the ionosphere
Author: Roger Godard1
1 Royal Military College of Canada
Corresponding Author: [email protected]
During the 1970’s a hot controversy emerged between in-situ measurements of the electron temper- ature in the ionosphere and ground measurements by incoherent backscatter radars. We suggest a possible explanation to this controversy. We define the “local” temperature of ionized species bythe variance of the square root of the energy, and here by: ∞ 3 ∫ − 1 2 Heren is the ambient density +∞ 1 m 3/2 [qϕ(r)+ mv ]/kT (r) 2n∞kT (r)= (qϕ(r)+ mv2)( ) e 2 d3v. (−2qϕ(r)/m)1/2 2 2πkT of the ionized gas, k the Boltzmann constant, T the temperature, q the charge, ϕ the electric potential at a point r and m is the mass. For repelled species, this equation has an analytical solution, and we
obtain: 3 −qϕ(r)/kT (r) 3 withtheconditions :limr→+∞ ϕ(r) = 0; limr→+∞ T (r) = 2kT (r)=e [qϕ(r)+ 2 kT (r)], T∞; limr→+∞ n(r) = n∞.Iftheelectricpotentialvanishes, thelocaltemperaturesofionizedspeciesgotowardstheirambienttemperatures.T hetheoreticalimplicationisthatthedistributionfunctionf(E,T(r))isnotaconstantalongatrajectoryinthephasespace, andthattheV lasovequationisviolated. Like Laframboise and Parker (1973), we shall consider an ionized gas without collisions and the ideal case of a potential well with a spherical symmetry, but there is no physical body. We define the num- ∫ ( )3/2 ( )∫ 3 m −qϕ(r) +∞ −mv2/2kT (r) 2 ′ ber density as: n = f d v = n∞ exp × e 4πv dv.F orrepelledspecies; wegeneralizeBoltzmann sformula :n(r) = [ ] 2πkT (r) kT (r) (−2qϕ(r)/m)1/2 −qϕ(r) n∞ exp kT (ϕ(r),r) .
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We now calculate particles fluxes for attracted∫ and repelled species.( This) will be a generalisation 3 − qϕ(a) of Laframboise and Parker’s (1973) formulas: J = fvr d v = J0 1 kT (ϕ(a),a) ,whereJ0 is the thermal[ flux] and a the radius of a spherical probe. For the repelled species, we have: J = −qϕ(a) J0 exp kT (ϕ(a),a) . In other words, the current due to repelled species is no longer an exponential! Our results also imply a modification of the PIC simulation methods. Because the temperature is no longer considered as a parameter but as a variable. Reference: Laframboise, J.G. and Parker L.W. (1973), {\it The Physics of Fluids}, p. 629.
M2-4 Emerging investigators in bioimaging and medical applications of optics (DPMB/DAMOPC) | Chercheurs émergeants en bioimagerie et applications médicales de l’optique (DPMB/DPAMPC) / 2392
Studying the brain across scales using imaging and physics
Author: Michèle Desjardins1
1 Université Laval
Corresponding Author: [email protected]
Functional Magnetic Resonance Imaging (fMRI) is a powerful tool to map brain activity non-invasively. Over the past 25 years, fMRI has become widely used in neuroscience research and is the foundation of tens of thousands of published studies. However, fMRI does not measure neurons directly. In- stead, in the most common form of fMRI called Blood Oxygen Level Dependent (BOLD), changes in the concentration of paramagnetic deoxyhemoglobin in the blood are detected. Although changes in blood oxygenation are correlated with neural activity, a quantitative relation has not been es- tablished, limiting the interpretation of data and the power of fMRI to study the brain in health or disease. Animal models provide invaluable insight into brain physiology for studying questions such as the cellular origin of fMRI. In mice, state-of-the-art optical technologies have been developed to probe neuronal activity as well as blood flow and oxygenation across spatial scales while manipulating cell- type-specific neuronal activity. However, translating such detailed results from laboratory animals into predictions relevant for human imaging requires both technical and theoretical efforts. In the first part of this talk, I will demonstrate a framework for imaging the brain of awake behaving mice across scales, from two-photon microscopy in individual ~10 micron wide cerebral arterioles and cells, to macroscopic fMRI. I will then show how high-resolution 3D images of cerebral vascu- lature measured in mice can be graphed into a connected network to model blood circulation using simple laws of physics. In this model, deep learning as well as equations of fluid dynamics, gas dif- fusion and the physics of magnetic resonance are leveraged to predict human brain imaging signals and improve their interpretation. Potential applications in neuroscience and fundamental cancer research will be discussed.
M1-4 Mathematical Physics (DTP) | Physique mathématique (DPT) / 2393
An Analytic Study of the Fourier Transform of the Gravitational Wave Pulsar Signal with Spin-down Effects
Author: Sree Ram Valluri1
Page 7 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Co-authors: Farrukh Chishtie 2; Xiyang Zhang 3
1 Department of Physics and Astronomy, University of Western Ontario 2 Department of Applied Mathematics, University of Western Ontario 3 Department of Statistical and Actuarial Sciences, University of Western Ontario
Corresponding Authors: [email protected], [email protected], [email protected]
The direct detection of gravitational waves from pulsars is a much anticipated discovery intheemerg- ing field of multi-messenger gravitational wave (GW) astronomy. In this context we develop an analytic approach to study the Fourier Transform (FT) of the GW pulsar signal including spindown effects. To incorporate the spindown effects, we incorporate an extended model of Alvarez andCar- raminana (2004), which includes the quadrupole term that accounts for the emission of gravitational radiation and assumes an inverse linear law of magnetic field decay of the pulsar (Chishtie etal, 2018). With this approach we are able to extract an all-order formula for the spindown parameters using the Taylor series representation of Jaranowski et al.(1998). We then include these spindown corrections in the overall FT expression of the GW pulsar signal and then analyze these corrections for the cases of the Crab, PSR B1509-58, PSR B0540-69 and Vela pulsars.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2394
32 - Localizing and excluding quantum information; or, how to share a quantum secret in spacetime
Author: Alex May1
1 University of British Columbia
Corresponding Author: [email protected]
When can quantum information be localized to each of a collection of spacetime regions, while also excluded from another collection of regions? We answer this question by defining and analyzing the localize-exclude task, in which a state must be localized to a collection of autho- rized regions while also being excluded from a set of unauthorized regions. This task is a spacetime analogue of quantum secret sharing, with authorized and unauthorized regions replacing authorized and unauthorized sets of parties. Our analysis yields the first quantum secret sharing scheme for arbitrary access structures for which the number of qubits required scales polynomially with the number of parties. We also study a second related task called state-assembly, in which shares of a quantum state are requested at sets of spacetime points. We fully characterize the conditions under which both the localize-exclude and state-assembly tasks can be achieved, and give explicit proto- cols. Finally, we propose a cryptographic application of these tasks which we call party-independent transfer.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2395
6 - Experimental Detection of Qubit-Ququart Pseudo-Bound En- tanglement using Three Nuclear Spins
Author: Amandeep Singh1
Co-authors: Akanksha Gautam 1; Arvind Arvind 1; Kavita Dorai 1
1 Indian Institute of Science Education and Research Mohali
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Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
In this work, we experimentally created and characterized a class of qubit-ququart PPT (positive under partial transpose) entangled states using three nuclear spins on a nuclear magnetic resonance (NMR) quantum information processor. Entanglement detection and characterization for systems with a Hilbert space dimension ≥ 2⊗3 are nontrivial since there are states in such systems which are both PPT as well as entangled. The experimental detection scheme that we devised for the detection of qubit-ququart PPT entanglement was based on the measurement of three Pauli operators with high precision and is a key ingredient of the protocol in detecting entanglement. The family of PPT-entangled states considered in the current study are incoherent mixtures of five pure states. All the five states were prepared with high fidelities and the resulting PPT entangled states were prepared with mean fidelity ≥ 0.95. The entanglement thus detected was validated by carrying out full quantum state tomography (QST).
W1-6 Tests of quark and lepton flavour (PPD) | Tests de saveurs de quarks et leptons (PPD) / 2396
A Visualization of the Belle II Detector Through Photon Conver- sions
Author: Ryan MacGibbon1
1 McGill University
Corresponding Author: [email protected]
The Belle II experiment represents an exciting opportunity to study the properties of Bmesonde- cays and to explore the nature of CP-violation and rare decays through electron-positron collisions. Belle II is designed to operate at an instantaneous luminosity of 8x1035 cm- 2s-1, 40 times that of previous B factory experiments. Following a successful commissioning run in 2018, the high luminosity data taking program has begun in early 2019. Opti- mal performance of the Belle II detector requires precise knowledge of the position and distribution of material within the detector. Using the detector’s precise vertex reconstruction methods, analy- sis of the material makeup and geometry can be performed using photon conversions. Within the detector, gamma rays produced by bremsstrahlung undergo pair production as they interact with nuclei within detector material. These e+/e- pairs propagate through the detector and are detected by tracking sub-detectors such as the Silicon Vertex Detector (SVD) and Central Drift Chamber (CDC). The path of these lepton pairs can then be reconstructed tothepoint of conversion within the material, and due to the relationship between the type of material and rate of photon conversions, a detailed analysis of the detector’s material distribution can be performed. This presentation will discuss the analysis of photon conversions in early Belle II colliding-beam data and present quantitative and visual results of the distribution of material within the Belle II detector. This presentation will also discuss the future plans and goals of this materials studyfor Belle II!
R1-4 Molecular sciences: outreach, teaching and research (DPE/DAMOPC) | Sciences molécu- laires: rayonnement, enseignement et recherche (DEP/DPAMPC) / 2397
Engaging undergraduates in science using advanced in-class demon- stration technology
Authors: Valery Milner1; Marina Milner-Bolotin1; Oded Aminov1; Walter Wasserman1
1 UBC
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Engaging undergraduates in active learning is critical for advancing their scientific literacy, which plays increasingly bigger role in modern society. Introductory Physics-101 is one of our best plat- forms to achieve this goal. Yet because it examines fast-speed phenomena which cannot be seen by the naked eye (e.g. acoustic vibrations), keeping the students engaged is challenging. We have de- veloped an advanced in-class demonstration technology, based on a high-speed camera, for in-class demonstrations of fast phenomena that are impossible to visualize and analyse otherwise. In this talk, we will discuss the details of our approach and the results of its recent implementation.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2398
27 - Exact Diagonalization on Pyrochlore System
Author: chen wei1
1 Memorial University
Corresponding Author: [email protected]
In quantum physics, if we can find the eigenstates |ϕi⟩ of a Hamiltonian H, and the respective eigen- ergies Ei, we can calculate many aspects such as time evolution, or its thermal properties. Exact diagonalization is a method which can solve the Hamiltonian numerically. For a small Hamiltonian system, we can find the eigenvalues by solve the characteristic polynomial equation of the matrix. However, as the system goes larger, the calculation will go exponentially. Instead of calculating the eigenstates directly, We will use the unitary transformation matrix to block diagonalise the Hamil- tonian first. As a consequence, instead of solving the Hamiltonian directly, we will solve each block. In order to find the unitary transformation matrix U, we will use the symmetry of the Hamiltonian, and with the help of group theory, we can construct U matrix and do the block diagonalization. The space group for Pyrochlore is No.227, it contains the point group Oh with space translations. Here we consider the conventional cell contains 16 sites, and use three translations T1:(0, 1/2, 1/2), T2:(1/2, 0, 1/2) and T3:(1/2, 1/2, 0). Additionally, we also use the subgroup D2 and the time rever- sal symmetry. As a result, we will block diagonalise the Hamiltonian into 32 blocks, which can be analyze easily.
M1-4 Mathematical Physics (DTP) | Physique mathématique (DPT) / 2399
Double Spectrum Digraph of Quantum Group Gravity
Author: zhi-an luan1
1 china petroleum university, huadong
Corresponding Author: [email protected]
We establish the unitary representation theory of quantum group gravity. (i) A dual pair of nonlinear diffusion equations are presented, first describes the growth phase tran- sition process (as universe expansion); second describes the descent process (as Hall effect). These exactly analytical solutions explain the explicate and implicate physical causality, structure and law of dual quantum groups under nature gravity effects. We prove that nonlinear and linear operators are isomorphism under complex manifolds, then are connect, then some nonlinear diffusion equa- tions are exactly solvable. (ii) Using the Gelfand Mapping, we construct an exactly quantitative double spectrum digraph (DSD) of gravity phase evolution and coherent process, which reveal the essential detail of the phase tran- sition (coherent) as: spectrums of graviton operator, three levels of gravity energies, three phase transition orbits. This model discovers the relationships between the mass, spin and graviton, deter- mines the phase change limitations for particle and cosmology scales. (iii) This DSD model just is a modern mathematical physics version of an ancient mysterious FuXi
Page 10 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Hexagram, by which we exactly predict some fundamental physics constants, such as, Hubble param- eter, Planck constant, dark energy density, Newtonian gravitational constant. These results deepen the understand of gravity and Nature.
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2400
Wake Field and Trapped Resonant Mode Calculations for the BioXAS in-Vacuum Undulator
Author: Evan Ericson1
Co-author: Drew Bertwistle 2
1 Evan 2 Canadian Light SOurce
Corresponding Authors: [email protected], [email protected]
The Canadian Light Source 2.9 GeV electron synchrotron storage ring circulates 220 mAofbeam current distributed over 265 bunches. These bunches travel through several in-vacuum undulators, large magnet arrays housed in tapered vacuum chambers with a complex internal geometry. The electrons traveling through these vacuum chambers carry electromagnetic fields whose distribution is determined by the geometry and material properties of the boundary. Electromagnetic wake fields are induced when the electron travel through a boundary condition transition. The wake fields ofa lead particle can perturb the position and momentum of following particles or they may excite long lived but undesirable resonant modes in cavity-like vacuum chambers. Either case may drive beam instabilities. We have modeled these trapped modes with finite difference time domain codes. The results of these simulations, including the frequency and amplitude of these modes, are predicted in this report.
W1-2 Teaching for Physics Skills Development (DPE) | Développement d’aptitudes pour l’enseignement de la physique (DEP) / 2401
Reforming Intro Physics Labs to Focus on Innovation, Creativity, and Scientific Skills
Author: Mats Selen1
1 University of Illinois
Corresponding Author: [email protected]
Approaching a question without fear; coming up with an idea; designing an experiment; understand- ing assumptions; interpreting data; reasoning from evidence. Many physicists would claim they do this for a living, and most would be delighted to observe this behavior in their students, yet for a variety of reasons this is often not what we encourage in our introductory physics labs. We have developed a portable wireless lab system with the goal of putting simple yet powerful tools in the hands of every student, and we are currently implementing a new design-based approach to our introductory physics labs based on this tool. Our students invent experiments and acquire data both in and out of the classroom, and share their data with each other and with instructors using an integrated cloud based repository. This new approach is allowing us to shift the focus ofour introductory physics labs toward creativity, critical thinking, and communication.
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W2-1 Creative Education and Partnerships in Learning (DPE) | Éducation créative et partenar- iats d’apprentissage (DEP) / 2402
Physics Students as Museum Curators
Author: Joanne O’Meara1
1 University of Guelph
Corresponding Author: [email protected]
Third-year undergraduate physics students in our Science Communications course were assigned the task of designing, building, and testing hands-on activities tied to the grade 6 science curriculum. In partnership with the Guelph Museum, we then ran a week of activities for local-area schools to participate through field trips. This presentation will discuss the collaboration in more detail, highlighting feedback from elementary-school teachers and our student-designers. We had more than 700 students passing through the stations, and, building on the success of our first event, we are now planning for STEM Week 2019.
T3-4 Dark matter and dark sectors (PPD) | Matière sombre et secteurs sombres (PPD) / 2403
Dark matter in a dark sector
Author: David McKeen1
1 TRIUMF
Corresponding Author: [email protected]
Rather than being a single new species, the dark matter of the Universe could be a part ofamore complicated collection of new particles with its own nontrivial dynamics that interacts weakly with the standard model–part of a “dark sector.” I will discuss motivations for considering this possibility, recent developments, and the new avenues for discovery that have opened up.
T3-4 Dark matter and dark sectors (PPD) | Matière sombre et secteurs sombres (PPD) / 2404
Dark Sector Searches on ATLAS
Author: Alison Lister1
1 University of British Columbia (CA)
Corresponding Author: [email protected]
Despite the currently collected LHC datasets not seeming to show signs of easily observable physics beyond the Standard Model, there remains a number of areas still to be explored. One of these areas is the search for long-lived particles, typical signatures of Dark Sector models. These searches most often rely heavily on non-standard reconstruction within the ATLAS experiment. Standard reconstruction relies on the particles being promptly produced - or close to promptly produced for b-tagging - at the primary collision vertex. ATLAS is now carrying out a wide range of searches for long-lived particles whose decay lengths extend from slightly beyond typical B-hadron decays lengths (few mm) to several meters with decays within the muon spectrometers. A short overview of some recent such searches will be presented.
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M1-10 Materials synthesis and characterization I (DCMMP) | Synthèse et caractérisation de matériaux I (DPMCM) / 2405
Conduction electrons are entirely responsible for the heat gener- ated by a constant electric current flowing in a wire
Authors: Albert Curzon1; Frank Curzon2
1 SFU 2 University of British Columbia
Corresponding Authors: [email protected], [email protected]
It is shown that energy transported entirely by conduction electrons is totally responsible for the heat generated by a constant electric current in a wire and that possible energy flows associated solely with the electric and magnetic fields make no contribution whatsoever to the heat genera- tion.
M1-6 Physics in Medicine and Biology 101 (DPMB) | Physique en médecine et biologie 101 (DPMB) / 2407
Cyclotrons for Medicine
Author: Cornelia Hoehr1
1 TRIUMF
Corresponding Author: [email protected]
Since its invention, cyclotrons have a history for applications in medicine. This can be either in- directly via the production of medical isotopes in nuclear medicine as well as directly for external beam therapy for the treatment of cancer. At TRIUMF, we have been involved in both over the year, by treating cancer with beams of pions and then with protons, as well as a long history of medical isotopes – gamma and positron emitters for diagnostics, and beta and alpha emitters for therapy. In recent years Targeted Alpha Therapy (TAT) has shown impressive results in the treatment of incurable cancer. In TAT, alpha emitters like Ac-225 are attached to a targeting vector, a biomolecule, which accumulates in the cancer to be treated. As alpha emitters have high linear energy transfer (LET) and typically a short range in tissue, and together with its specific delivery system, they hold the promise to cure cancer that can not be treated with other therapies – surgery, chemotherapy or external beam therapy. Currently, there is a world-wide shortage of alpha emitters, which greatly hinders ongoing clinical trials. TRIUMF with its 520 MeV cyclotron, has the infrastructure in place to solve this shortage. In this presentation, the highlights over the years as well as the current research and developments are discussed.
R2-1 Workshop: Implementing Two-Phase Collaborative Physics Exams (DPE) | Atelier: exa- mens de physique collaboratifs en deux temps (DEP) / 2408
Four-way high-fives during exams: Adding a group phase to pro- vide immediate feedback and increase enjoyment
Authors: Jared Stang1; Joss Ives1
Page 13 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 University of British Columbia
Corresponding Authors: [email protected], [email protected]
Two-phase collaborative exams—or group exams, in which students first complete the exam individ- ually and then form groups to complete the same or similar questions—are a flexible and effective method for adding immediate formative feedback to what is traditionally a summative experience. This workshop will support participants to engage with the evidence for including a groupphase and to develop their own two-phase exam implementation plan. Specifically, by the end of this workshop, participants will be able to:
• Articulate the rationales for adding a group phase to a summative solo assessment. • Develop their own implementation plan for a group exam, in their context. • Provide specific recommendations to their students to maximize the student benefit from agroup exam.
The workshop will be collaborative and participatory, including a group-exam implementation work- sheet and an open discussion focussed on how to support students to maximize their productive en- gagement during a group exam. Preliminary results from our UBC Teaching and Learning Enhance- ment Fund-supported project “Evidence-based best practices for two-stage collaborative exams” will be shared.
T3-4 Dark matter and dark sectors (PPD) | Matière sombre et secteurs sombres (PPD) / 2409
Dark sector, dark matter, and related searches at Belle II
Author: Christopher Hearty1
1 University of British Columbia (CA)
Corresponding Author: [email protected]
The Belle II experiment has started operations at the SuperKEKB e+e- collider, located attheKEK laboratory in Tsukuba, Japan. Like its predecessors Belle and BaBar, Belle II will operate near the Y(4S) resonance. It has the goal of collecting a dataset 100x larger than that of BaBar. The experi- ment’s trigger has been designed to allow searches for a wide variety of dark sector particles and other low-mass particles predicted by theories beyond the Standard Model, including possible dark matter candidates. A small amount of data was recorded in the Spring of 2018. I will reviewthe status of searches using this initial data, and discuss future prospects, with particular emphasis on near-term discovery potential.
M1-10 Materials synthesis and characterization I (DCMMP) | Synthèse et caractérisation de matériaux I (DPMCM) / 2410
Electronic , Optical and Magnetic Properties of low concentration Ni doped CdSe by First Principle Method
Authors: Yaseen MuhammadNone; Dilawar MuhammadNone; Hina AmbreenNone; Shahid UmairNone; MisbahNone; Butt Mehwish KhalidNone; Ghaffar AbdulNone; Ren WeiNone
Electronic , Optical and Magnetic Properties of low concentration Ni doped CdSe by First Principle Method M. Yaseen,1, M. Dilawar1, H. Ambreen1, U. Shahid1, Misbah2, M. K. Butt1, A. Ghaffar1, and W. Ren3 1Department of Physics, University of Agriculture, Faisalabad 38040, Pakistan 2Department of Chemistry, University of Agriculture , Faisalabad 38040, Pakistan
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3Electronic Material Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China.Corresponding Author: [email protected] In this work, electronic, optical and magnetic properties of low concentration Ni doped CdSe was studied systematically by Wien 2K code. Calculations were performed for the band structure in the spin up and down channels, total density of states (TDOS) and partial density of states (PDOS). The Spin-polarized band structure showed that Cd0.9375 Ni0.0625 Se, Cd0.875 Ni0.125 Se and Cd0.75 Ni0.25Se are half metallic ferromagnetic in nature with direct band gap, when the concentration of the transition metal increases the band gap is also increased. In optical properties, we discuss about absorption coefficient, optical conductivity, reflectivity, refractive index, real and imaginary partof dielectric function. Analyzed magnetic properties of Ni doped CdSe compound offers the magnetic moment which indicates the magnetic properties due to d orbital of Ni atoms. Obtained results re- vealed that Cd1-xNix Se is a suitable and potential candidate for the spintronics and optoelectronics devices. Key word: Density functional theory; Optical properties, Dilute magnetic semiconductor
T3-4 Dark matter and dark sectors (PPD) | Matière sombre et secteurs sombres (PPD) / 2411
Searches for Dark Sectors in Fixed-Target Experiments
Author: Miriam Diamond1
1 SLAC National Laboratory
Corresponding Author: [email protected]
The leading dark matter (DM) paradigm over the past few decades has been that of a Weakly Interact- ing Massive Particle with a mass of tens of GeV to a few TeV. But in light of recent experimental con- straints, attention is increasingly turning to models with lower-mass DM, especially in the context of a “dark sector” featuring dark mediators and multiple DM particle species. Probing such models requires exploiting complementarity between different types of DM searches, where electron-beam fixed-target experiments play an important role in the DM mass range of a few to hundreds ofMeV. These experiments seek to generate dark sector particles, such as dark photons, via electron-nucleus scattering and emission processes analogous to standard bremsstrahlung. Identifying the visible decay products of the dark sector particles, such as electron-positron or muon-antimuon pairs, re- quires precise reconstruction of narrow mass resonances and/or displaced vertices; accounting for invisible decay products requires precise missing energy and/or momentum measurements. In this talk, I will give an overview of the landscape of current and planned fixed-target DM searches, with the Heavy Photon Search (HPS) and its planned successor LDMX (Light Dark Matter eXperiment) as specific examples.
W2-7 Condensed Matter Theory I (DCMMP) | Théorie de la matière condensée I(DPMCM) / 2412
Possible Flexoelectric Origin of the Lifshitz Transition in Stron- tium Titanate Interfaces
Authors: Bill Atkinson1; Amany Raslan1
1 Trent University
Corresponding Authors: [email protected], [email protected]
Multiple experiments have observed a sharp transition in the band structure of LaAlO3/SrTiO3 (001) interfaces as a function of applied gate voltage. This Lifshitz transition, between a single occupied band at low electron density and multiple occupied bands at high density, is remarkable for its abrupt- ness. In this work, we propose a mechanism by which such a transition might happen. We show
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via numerical modeling that the simultaneous coupling of the dielectric polarization to the interfa- cial strain (”electrostrictive coupling”) and strain gradient (”flexoelectric coupling”) generates a thin polarized layer whose direction reverses at a critical density. The Lifshitz transition occurs concomi- tantly with the polarization reversal and is first-order at T = 0. A secondary Lifshitz transition, in which electrons spread out into semiclassical tails, occurs at a higher density.
M2-2 Fundamental Symmetries (DNP) | Symétries fondamentales (DPN) / 2413
Anti-neutrino Energy Spectrum and Ground State Branching Ra- 92 92 − tio of Laser Trapped Rb → Srβ ν¯e
Authors: James McNeil1; John Behr2; Alexandre Gorelov2; Melissa Anholm3; Dan Melconian4; Danny Ashery5
1 UBC 2 TRIUMF 3 University of Manitoba 4 Texas A&M 5 University of Tel Aviv
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Reactor neutrino oscillation experiments observe two anomalies in anti-neutrino energy spectra: a total deficit of events, and an event excess in the 5-7 MeV range compared to theory. A total deficit in anti-neutrino flux may support a non-SM sterile neutrino, but both discrepancies may result from inadequate understanding of the reactor fuel cycle. In the 5-7 MeV range first-forbidden 0− → 0+ 92 decays account for 30% of the total anti-neutrino (ν¯e) flux, with Rb ground-state to ground-state − + branch (GSB) alone accounting for 30-50% of 0 → 0 ν¯e flux. Model predictions will be improved 92 by measuring the ν¯e energy spectra from Rb decay, and measuring the strong GSB ratio with projected 2% accuracy and independent systematics to traditional total absorption spectrometers. Using the TRINAT neutral atom trap, and measured momenta of beta and recoiling 92Sr daughter, kinematic reconstruction of ν¯e energy spectra, decay Q-value, GSB ratio, and beta-neutrino angular correlation coefficient aβν are examined experimentally.
T4-9 Quantum Theory (DTP) | Théorie quantique (DPT) / 2414
Operational, gauge-free quantum tomography
Author: Olivia Di Matteo1 Co-authors: John Gamble 2; Christopher Granade 2; Kenneth Rudinger 3; Nathan Wiebe 2
1 TRIUMF 2 Microsoft Research 3 Sandia National Laboratories
Corresponding Author: [email protected]
As quantum processors become increasingly refined, benchmarking them in useful ways becomes a critical topic. Traditional approaches to quantum tomography, such as state tomography, suf- fer from self-consistency problems, requiring either perfectly pre-calibrated operations or measure- ments. This problem has recently been tackled by explicitly self-consistent protocols such asran- domized benchmarking, robust phase estimation, and gate set tomography (GST). An undesired side- effect of self-consistency is the presence of gauge degrees of freedom, arising from the lackfiducial
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reference frames, and leading to large families of gauge-equivalent descriptions of a quantum gate set which are difficult to interpret. We solve this problem through introducing a gauge-free representation of a quantum gate set in- spired by linear inversion GST. This allows for the efficient computation of any experimental fre- quency without a gauge fixing procedure. We use this approach to implement a Bayesian version of GST using the particle filter approach, which was previously not possible due to the gauge. Within Bayesian GST, the prior information allows for inference on tomographically incomplete data sets, such as Ramsey experiments, without giving up self-consistency. We demonstrate the stability and generality of both our gauge-free representation and Bayesian GST by simulating a number of common characterization protocols, such as randomized benchmarking, as well characterizing a trapped-ion qubit using experimental data. Sandia National Labs is managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a subsidiary of Honeywell International, Inc., for the U.S. Dept. of Energy’s National Nuclear Security Administration under contract DE-NA0003525.The views expressed in this presen- tation do not necessarily represent the views of the DOE, the ODNI, or the U.S. Government. This material was funded in part by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research Quantum Testbed Program.
M1-2 Exploring the energy frontier (PPD) | Explorer la frontière d’énergie (PPD) / 2415
Run-2 physics results from the ATLAS experiment at the Large Hadron Collider
Author: Bernd Stelzer1
1 SFU
Corresponding Author: [email protected]
With the successful completion of Run-2 at the Large Hadron Collider, the ATLAS experiment recorded more than 140 fb-1 of integrated luminosity of pp collision data at 13 TeV centre-of-mass energy. This talk will review the latest results based on this wealth of new data in the areaofthe Brout-Englert-Higgs sector, important Standard Model processes and searches for physics phenom- ena beyond the Standard Model.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2416
Interacting Gravitational Waves
Authors: Arundhati Dasgupta1; Siddhartha Morales GuzmanNone
1 University of Lethbridge
Corresponding Author: [email protected]
We discuss gravitational waves interacting with scalar particles and neutrinos. We discuss the phys- ical implications of the results for detection on earth and early universe cosmology.
M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2417
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Physics outreach and Gender: Tribute to Dr. Li-Hong Xu
Author: Arundhati Dasgupta1
1 University of Lethbridge
Corresponding Author: [email protected]
In this talk we describe how young minds can be influenced by outreach programs aimed at the feminine gender. We pay a tribute to Dr. Li-Hong Xu and her contributions to this effort.
T2-8 Magnetic resonance imaging (DPMB) | Imagerie par résonance magnétique (DPMB) / 2418
Axon Diameter Inferences in the Corpus Callosum and Fornix of the Mouse Brain from Images with Low SNR
Author: Sheryl Herrera1
Co-authors: Morgan Mercredi 2; Henri Sanness Salmon 2; Guneet Uppal 2; Domenico Di Curzio 2; Melanie Martin 2
1 University of Winnipeg, Cubresa Inc. 2 University of Winnipeg
Corresponding Author: [email protected]
It is thought that the diameters of axons change due to disease. Until recently measurements of axon diameters (AD) could only be done invasively. AD can now be inferred non-invasively using a magnetic resonance imaging temporal diffusion spectroscopy (TDS) technique that requires many images to be collected with a range of diffusion-times or frequencies. Collecting many images to average together for a higher signal-to-noise ratio (SNR) becomes too time-consuming. Thus, low SNR (5-6) images of mouse brain were analyzed to infer axon sizes. TDS methods require many measurements at different gradient strengths and frequencies making data collection time consuming and difficult to obtain high SNR in a reasonable amount of time.This work uses oscillating gradient TDS to study the corpus callosum (CC), fornix and optic tract (OT) of the mouse brain under the condition of low SNR to determine if reasonable results can be obtained with low SNR. A 15.5 week-old female mouse (Kras/p53 on a C57BL/6 background) was perfused with formalin. Brain (in skull) was soaked in a formalin solution for 24 hours then transferred into a Phosphate- buffered saline (PBS) solution for 24 hours then transferred into another PBS solution for24hours prior to imaging to filter out any remaining formalin. All experiments were approved by bothUni- versities’ Animal Care Committees. The sample was imaged using a 7 T Bruker Avance III NMR system with Paravision 5.0withaBGA6 gradient set with a maximum gradient strength gmax of 430357 Hz/cm, and a 3.5 cm diameter bird cage RF coil. Each 20 ms apodised cosine gradient pulse ranged from n=1-20, in steps of 1. Two different gradient strengths were used for each frequency and gradient pulses were separated by 24.52 ms. TDS was able to infer ADs of 4.8±1.2µm in the CC and 2.4±0.6µm in the fornix using low SNR im- ages. The models used to infer ADs assume the diffusion gradient direction to be perpendicular to the axons. The gradient direction was approximately parallel to the axons in the OT and wesuspect this explains why we were unable to infer ADs in the OT. The gradient frequency range successfully targeted ADs ~2-4 µm in the fornix and CC. The low SNR did not seem to have an effect on the ability of the method to infer ADs. This study is the first step toward showing the feasibility of usingOGSE TDS to infer ADs in situations of low SNR. Acknowledgements The authors thank NSERC for financial support.
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DTP Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPT et finales du concours d’affiches étudiantes (4) / 2419
21 - Mass, Light and Gravity in Unitary Space-Time
Author: zhi-an luan1
1 china petroleum university hua-dong
Corresponding Author: [email protected]
We are surprised to find that the major open questions that plague modern theoretical physics can be answered in the mysterious “I Ching” book, by which our understanding on Mass and Gravity is: (1) The triplets of particle mass, electric (or magnetic) charges, light and gravity are natural rep- resentations of quantum groupoid in unitary space-time (XTX). Mass “m” is a static topological measurement of this XTX, and light speed “c” is a dynamic topological measurement for it. The coherent states of quantum groupoids is dominated by gravity behind the scenes, gives rise to the next generation and form a reproductive chain. (2) By split and recast nonlinear Schrodinger and Laplace operators, we cast a Double Spectrum Digraph (DSD) ensemble, which is a quantum group version of the ancient I Ching, which can accu- rately locate inertial mass, White or Black Holes, critical points of phase transition, and flip points. Its 8x8 non-Hermitian R-Matrix carries almost all the quantum information and envelops all the quantum evolutions. By the derived new generation subgroup as an example, we give the analytical images of growth and annihilation of the dual mass under gravity. (3) We find three different quantum tunnels in each hexagonal honeycomb structure, which exactly describe: trivial spin, dynamic spin and coherent spin. Dynamic spin just is instantaneous collision, coherent spin is induced by gravity to form outer spin. We find the law of quantum coherence: Sum of mass-velocity2 = Product of mass-velocity2 = Id. (4) We discover a new gravity mode, which suits to quantum states of a mass triplet: fusion, coher- ence and separation, by which we found the theoretical values of gravity constant G.
T3-1 Soft Matter PM-1 (DCMMP) | Matière molle PM-1 (DPMCM) / 2420
The Packing of Soft Spheres
Author: An-Chang Shi1
1 McMaster University
Corresponding Author: [email protected]
The packing of spheres is an interesting problem in mathematics and physics with a longhistory dated back to the work of Kepler and Lord Kelvin. In recent years, intricate periodic and aperiodic spherical packing phases have emerged in a host of soft matter systems including supramolecular assemblies, surfactants and block copolymers, underscoring the universality of emergent order in condensed matter. In particular, the rich phase behavior of block copolymers provides anideal model system to study the origin and stability of order phases in soft matter. Our recent study of block copolymer systems using the self-consistent field theory reveals that one key mechanism of forming complex spherical phases is the conformational asymmetry of the blocks. Furthermore, we have predicted that the segregation of different polymeric species in block copolymer blends provides another mechanism to stabilize spherical packing phases with very different sized-spherical domains. I will summarize recent progresses on this fascinating topic and discuss possible future research directions.
T2-4 Indirect and collider searches for dark matter (PPD) | Recherches indirectes et par colli- sionneurs pour la matière sombre (PPD) / 2421
Page 19 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Indirect searches for dark matter: annihilation, decay and col- lider production
Author: Aaron Vincent1
1 Queen’s University
Corresponding Author: [email protected]
Models of particle dark matter (DM) that lead to the observed relic abundance today generically pre- dict ongoing annihilation or decay into energetic standard model particles. Effective couplings to the standard model also imply that particle colliders such as the LHC can produce invisible particles which could be detected via enhancements in collision cross sections, or as missing energy and mo- mentum. I will briefly review the theory behind indirect and collider searches, sketching out current constraints. I will then turn to exploring the myriad, complementary searches for DM annihilation and decay products using messengers such as gamma rays, cosmic rays, neutrinos, and the cosmic microwave background, as well as data from stellar astrophysics and cosmology.
R2-7 Nuclear Structure IV (DNP) | Structure nucléaire IV (DPN) / 2422
Nuclear structure and dynamics from ab initio theory
Author: Petr Navratil1
1 TRIUMF
Corresponding Author: [email protected]
A realistic description of atomic nuclei, in particular light nuclei characterized by clustering and low-lying breakup thresholds, requires a proper treatment of continuum effects. We have developed a new approach, the No-Core Shell Model with Continuum (NCSMC) [1,2], capable of describing both bound and unbound states in light nuclei in a unified way. With chiral two- and three-nucleon interactions as the only input, we are able to predict structure and dynamics of light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We will discuss our NCSMC calculations of polarization effects in the 3H(d,n)4He fusion and its mirror reaction 3He(d,p)4He [3]. These transfer reactions are relevant for primordial nucleosynthesis and 3H(d,n)4He in particular is being explored in large-scale experiments such as NIF and ITER as a possible future energy source. Next, we will present latest NCSMC calculations of weakly bound states and resonances of exotic halo nuclei 11Be and 15C and discuss the photo-dissociation of 11Be and 14C(n,γ)15C capture. We will also present our results for their unbound mirror nuclei 11N and 15F, respectively. We will point out the effects of continuum on the structure of mirror resonances and highlight the role of chiral NN and 3N interactions and make connections to TRIUMF experimental results. Supported by the NSERC Grant No. SAPIN-2016-00033. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. [1] S. Baroni, P. Navrátil, and S. Quaglioni, Phys. Rev. Lett. 110, 022505 (2013); Phys. Rev. C87, 034326 (2013). [2] P. Navrátil, S. Quaglioni, G. Hupin, C. Romero-Redondo, A. Calci, Physica Scripta 91, 053002 (2016). [3] G. Hupin, S. Quaglioni, and P. Navrátil, Nature Communications (2019) 10:351; https://doi.org/10.1038/s41467- 018-08052-6
T4-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-2 (DPN) / 2423
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John D’Auria, the relativistic chemistry of francium, and MeV- mass neutrinos
Author: John Behr1
1 TRIUMF
Corresponding Author: [email protected]
TRIUMF’s neutral atom trap (TRINAT) was started as a good match for surface-ionized alkali ele- ments produced at TISOL (TEST/TRIUMF Isotope Separator On-line). TRINAT had two main goals– beta-neutrino correlations, and the chemistry of francium champi- oned by John D’Auria. Relativity makes francium’s properties harder to extrapolate from the lighter alkali elements; e.g., the ionization potential is higher than cesium’s due to a more deeply bound S ground-state orbital, while production of ultracold molecular dimers by photoassociation is predicted to be stymied. TRINAT failed in its first attempt to trap beta-decaying potassium isotopes, but we fixed aten linewidth error in our estimated atomic resonance location and succeeded two weeks later, largely because TISOL had admirable flexibility. TRINAT also failed to trap 226Fr in 1996, and francium was not trapped at TRIUMF for another fif- teen years. Diverted personnel searched for MeV-mass neutrinos instead [M. Trinczek et al. PRL 2001], prividing a cosmology tie-in to the symposium title.
R2-5 Detectors for Discovery (PPD/DAPI) | Détecteurs pour la découverte (PPD/DPAI) / 2424
Upgrades to the ATLAS Detector at the Large Hadron Collider
Author: Jesse Alan Heilman1
1 Carleton University (CA)
Corresponding Author: [email protected]
The Large Hadron Collider (LHC) had entered the second of its long shutdown phases formainte- nance and upgrades. Concurrently, the ATLAS detector is also undergoing several upgrades targeted at improving the ability of the detector to collect data during future LHC operation. This talk will focus on this so-called Phase-I upgrade to the Liquid Argon Calorimeter electronics and the con- struction of the New Small Wheel of the Muon Spectrometer - to both of which Canada is a major contributor. Additionally, the schedule for the future Phase-II upgrades, including Canada’s contri- butions, will be summarized.
M1-9 Soft Condensed Matter I (DCMMP) | Matière condensée molle I(DPMCM) / 2425
Electrokinetic transport in porous media
Authors: Mpumelelo Matse1; Michael Eikerling2; Peter Berg3
1 Simon Fraser University 2 Simon Fraser university 3 University of Alberta
Corresponding Authors: [email protected], [email protected], [email protected]
Electrokinetic transport phenomena, predominantly realized in charged polymeric and porous me- dia, offer possibilities for applications in nanofluidic systems, energy harvesting and biosensing. In
Page 21 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
this work, we present a theoretical and numerical study of nonlinear coupling between wall deforma- tion and the flows of water and ions in a charged, deformable nanochannel. The classical treatment of mass and momentum conservation in the solid-liquid coupled system is based on the Stokes- Poisson–Nernst–Planck equations. For elastic but non-viscous walls in the limit of small deforma- tion, analytically solvable differential equations were obtained in one dimension. The response ofthe walls’ relaxation dynamics and the channel’s electrokinetic transport was investigated at different charging regimes. Within the framework of nonequilibrium thermodynamics, compact formulae in terms of Onsager’s phenomenological coefficients were derived for the electrokinetic transport pa- rameters and energy conversion efficiency. Furthermore, an extension of the model is presented for electroactuator modelling which operates through a coupling of electrical and mechanical interac- tions for closed nanochannels. In this scenario, we explore numerically the transient dynamics and steady-state solutions for closed, finite nanopores. A full theoretical account, along with numerical results, of the effect of membrane charging and mechanical response on the differential capacitance is presented.
R2-4 Testing Fundamental Symmetries II (DTP/PPD/DNP) | Tests de symétries fondamentales II (DPT/PPD/DPN) / 2426
Limits on exotic contributions to electroweak symmetry break- ing
Author: Heather Logan1
1 Carleton University
Corresponding Author: [email protected]
The Standard Model breaks electroweak symmetry using an isospin-doublet scalar Higgs field, i.e.a field in the minimal nontrivial representation of SU(2)_L. But there could in principle becontribu- tions to the vacuum condensate from “exotic” scalars in higher isospin representations. Such exotic models are in general strongly constrained by electroweak precision measurements, which I’ll use to set bounds on the maximum contribution of the exotic scalars to the W and Z boson masses. Model- building can get around these bounds, allowing larger contributions to the W and Z masses and deviations in the discovered Higgs boson’s couplings; these models comprise the Georgi-Machacek model, its generalizations to higher isospin, and the scalar septet model. These models predict a dis- tinctive phenomenology involving doubly-charged scalars that couple to W boson pairs, which have been directly searched for at the LHC and in turn constrain the exotic scalars. I’ll review the models and their constraints, and try to summarize what we can say so far about exotic contributions to electroweak symmetry breaking.
R1-4 Molecular sciences: outreach, teaching and research (DPE/DAMOPC) | Sciences molécu- laires: rayonnement, enseignement et recherche (DEP/DPAMPC) / 2427
Astronomical observations: an introduction for physicists
Author: Pauline Barmby1
1 University of Western Ontario
Corresponding Author: [email protected]
Observational astrophysics uses sophisticated technology to collect and measure electromagnetic and other radiation from beyond the Earth. Getting the best out of modern observatories requires the expertise of specialists in many fields beyond astronomy, from physicists to civil engineers to statisticians and software engineers. The goal of this talk is to introduce the essentials of professional astronomical observations to physicists, and especially physics students, who have not previously been exposed to astrophysics. It will provide context and relevant background about both facility
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construction and data analysis, covering the path of electromagnetic radiation through telescopes, optics, detectors, and instruments, and its transformation through processing into measurements and information.
T1-4 Direct Detection of Dark Matter (PPD) | Détection directe de la matière sombre (PPD) / 2428
Overview of Dark Matter Direct Detection
Author: Joseph Bramante1
1 Queen’s University
Corresponding Author: [email protected]
An overview of dark matter detection in the Milky Way galactic halo will be presented, including constraints and cutting-edge searches for dark matter’s interactions with nuclei and electrons. The theory of non-relativistic dark matter interactions, connections with early universe cosmology, and the status of underground dark matter experiments will be addressed, along with some new detection methods, including high-recoil energy searches for inelastic dark matter and multiscatter searches for very heavy dark matter.
W2-9 Hadronic Physics (DNP/DTP) | Physique hadronique (DPN/DPT) / 2429
Dynamical spin effects in the pion light-front wavefunction
Author: Mohammad Ahmady1
Co-author: Ruben Sandapen 2
1 Mount Allison University 2 Acadia University
Corresponding Authors: [email protected], [email protected]
In this talk, I show how augmenting the pion light-front wavefunction with a dynamical spin com- ponent leads to a significant improvement in predicting observables like the mean charge radius, the decay constant, the space-like electromagnetic form factor, the twist-2 pion distribution am- plitude and the photon-to-pion transition form factor. Holographic light-front wavefunction for a pseudoscalar meson is used for producing the results. The proposed dynamical spin wavefunction is then extended to other members of the lightest pseudoscalar nonet and the consequences are discussed.
R1-1 History of Physics (DHP) | L’histoire de la physique (DHP) / 2430
Pierluigi Falco (1977-2014) and his Contributions to Mathemati- cal Physics
Author: Francesco Barletta1
1 CMÉC
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Corresponding Author: [email protected]
On the fifth anniversary of his death, we want to remember Dr. Pierluigi Falco, Assistant Profes- sor of Mathematics at the California State University (CSU) in Northridge. Dr. Falco completed a Degree in Physics at Università La Sapienza in Rome, and a PhD in Mathematics at the same univer- sity, followed by a postdoctoral position in the Mathematics Department at the University of British Columbia in 2007. Then, after two years as a postdoctoral member at the School of Mathematics in Princeton, he was hired as an Assistant Professor at CSU. During his short life, Dr. Falco made im- portant theoretical contributions in both classical and quantum statistical mechanics, mathematical methods in solid state theory, and quantum field theory. Here, we want to commemorate someof these contributions to the Canadian physics community.
M2-10 Soft condensed matter II (DCMMP) | Matière condensée molle II (DPMCM) / 2431
β-NMR Studies of the Temperature and Depth Dependence of Dy- namics in Polystyrene Thin Films
Author: Iain McKenzie1
Co-authors: Yu Chai 2; David Cortie 3; James Forrest 4; Derek Fujimoto 3; Victoria Karner 3; Robert Kiefl 3; Phillip Levy 1; Andrew MacFarlane 3; Ryan McFadden 3; Gerald Morris 1; Matthew Pearson 1; Adam Raegen 2; Shipei Zhu 2
1 TRIUMF 2 University of Waterloo 3 University of British Columbia 4 University of waterloo
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], fu- [email protected], [email protected], [email protected], [email protected], [email protected]
The decrease of the glass transition in polystyrene thin films with decreasing film thicknesshas given rise to the suggestion that there is a region near the free surface where there are faster dynam- ics than in the bulk. This surface mobility has been directly measured, but there are few studiesof how the enhanced dynamics varies with distance from the free surface. We have used β-detected nuclear magnetic resonance (β-NMR) of implanted 8Li+ to directly probe the temperature and depth dependence of the γ-relaxation mode, which is due to phenyl rings undergoing restricted rotation, in thin films of atactic deuterated polystyrene (PS-d8). I will show that the activation energyfor the γ-relaxation is lower near the free surface and returns to bulk values at depths of ∼10 nm and discuss how the depth dependence of γ-relaxation is affected by sample processing (such as anneal- ing, floating on water and the inclusion of a surfactant), and by the presence of a buried interface. I will introduce a novel hole-burning (selective saturation) β-NMR technique that has been used to measure the depth dependence of the fluctuation rate of a much slower relaxation process.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2432
70 - WITHDRAWN - Search for dark matter in events with miss- ing transverse momentum and a Z boson produced in 13 TeV proton- proton collisions with the ATLAS detector at the LHC
Author: Kayla McLean1
1 University of Victoria (CA)
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Corresponding Author: [email protected]
The Large Hadron Collider (LHC) Run II took place from 2015 until the end of 2018, withproton- proton collisions at 13 TeV centre-of-mass energies. During this time the ATLAS detector collected a large dataset of over 140 fb−1. Some theories predict that WIMP dark matter can be produced in proton-proton collisions, yielding events with large missing transverse momentum carried by a dark matter particle-antiparticle pair. Our search focuses on events where the recoil isina Z boson decaying to e+e− or µ+µ−. In this talk an overview of the search will be presented, including the signal models studied, major backgrounds and their estimation techniques, and the procedure used to set limits on the dark matter particles. Results will be presented using the 2015+2016 dataset, and prospects for the full Run II analysis will be discussed.
R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2433
Neutrino Oscillations at T2K and Hyper-K
Author: Mark Hartz1
1 TRIUMF & Kavli IPMU, University of Tokyo
Corresponding Author: [email protected]
The discovery of neutrino oscillations has established non-zero neutrino mass and impliesnew physics beyond the standard model to generate neutrino masses. T2K is a long baseline accelerator- based neutrino oscillation experiment in Japan, studying the oscillations of a muon (anti)neutrino beam. T2K is making world leading measurements of neutrino oscillation parameters, including the first constraints on the phase governing CP violation/conservation in neutrino oscillations. Hyper-K is a proposed successor to T2K with an 8-times larger detector and 2.5-times higher beam intensity. Hyper-K will collect large statistical samples of neutrino oscillations, searching for CP violation in the neutrino sector and making precision measurements of neutrino oscillation parameters. Hyper- K will also have a broad program of physics including nucleon decay searches, supernova neutrino detection, solar neutrino oscillation measurements and dark matter searches. In this talk, I will re- view the status of the T2K experiment and discuss the physics program of Hyper-K and the progress towards the realization the project.
T2-8 Magnetic resonance imaging (DPMB) | Imagerie par résonance magnétique (DPMB) / 2434
Simultaneous Positron Emission Tomography (PET)/Magnetic Res- onance (MR) Imaging
Authors: Melanie Martin1; Vanessa Palmer2; Sheryl Herrera3; Katrina Armstrong4; Katinka Stecina4; Melissa Anderson1; Henri Sanness Salmon1; Huixin Zhang5; Michael Zhang1; Liping Huang6
1 University of Winnipeg 2 Cubresa, Inc 3 University of Winnipeg, Cubresa, Inc. 4 University of Manitoba 5 Winnipeg Regional Health Authority 6 Department of Physical TherapyChinese PLA General HospitalBeijingChina
Corresponding Author: [email protected]
Magnetic resonance imaging (MRI) is a non-invasive tool. Conventional MRI provides anatomical images with little information about the function of the anatomy. Positron emission tomography
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(PET) provides images of the function of the organs (e.g. glucose uptake) non-invasively with no anatomical information. Functional MRI (fMRI) gives information of blood oxygenation level within the central nervous system which is related to function. Combining both MRI and PET allows the visualization of functional and anatomical changes together providing much more information than either method can provide on its own. When one image is acquired before another, it is difficult to align the images (image registration) because of motion of the subject. If the organ being imaged moves due to respiration, for instance, then image registration is even more challenging. If the subject’s physiological response and/or anatomy varies with time, the images from the two different modalities when collected at different times do not necessarily capture the same changes, making correlation of results difficult. Simulta- neous PET/MR imaging can be used to overcome many of these challenges. Here we present data acquired from simultaneous PET/MR imaging. The MR images were acquired with a 7T 21 cm bore Bruker Avance III NMR system with Paravision 5.0. The PET images were acquired with a NuPET (Cubresa, Inc)with a 67.2 mm (axial) x 58.9 mm (transaxial) field of view which was inserted in the bore of the magnet. These data will demonstrate the feasibility and utility of simultaneous PET/MR imaging. Acknowledgements The authors thank NSERC for financial support.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2435
1 - Magnetic shield changes with time and temperature
Authors: Benedict Feinberg1; Harvey Gould1
1 Lawrence Berkeley National Laboratory
Corresponding Authors: [email protected], [email protected]
Magnetic shielding is a necessary component of electric dipole moment experiments and other pre- cision measurements. Understanding the details of its behavior can improve the outcome of ex- periments. We have previously reported (AIP Advances 8, 035303 [2018]) that delayed changes in magnetization cause the magnetic flux density inside a Permalloy (mu-metal) shielded volume to decrease over hours and days. To test if this effect changes with temperature, we are performing similar measurements on a warmed shield. In a magnetically nulled region, the shield, wrapped with heating tapes and insulation, is heated to about 45 ◦C. The heaters are then turned off, andthe shield demagnetized by passing a 60 Hz current through a toroidal winding. After a short wait, an external magnetic field is applied and the magnetic flux density in the center of the shielded volume is monitored over the next few hours. Preliminary results will be presented.
W1-6 Tests of quark and lepton flavour (PPD) | Tests de saveurs de quarks et leptons (PPD) / 2436
Status of the Belle II experiment and overview of early semi-leptonic and leptonic results
Author: Racha Cheaib1
1 University of British Columbia
Corresponding Authors: [email protected], [email protected]
The Belle II experiment, located at SuperKEKB in Tsukuba Japan, collected around 500 pb-1dur- ing its commissioning run in 2018. After the integration of its vertex detector, the experiment has recently started its first full run in March 2019. The goal of Belle II is to to collect datawithatar- get integrated luminosity of the experiment is 50 ab-1. The large dataset has a unique capability
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of reaching high precision in many areas of B physics, specifically leptonic and semileptonic Bde- cays with missing energy. In this talk, we will present an overview of the Belle II experiment and its current status. Results from the 2018 Belle II commissioning run will be shown, including the rediscovery of the B meson using semileptonic decays. In addition, a novel B tagging technique to be used in many Belle II measurements, called the Full Event Interpretation (FEI), will be presented and its performance with early 2018 and 2019 data will be shown. Furthermore, we will also present an overview of the semileptonic B decays that will be measured in the upcoming years at Belle II and discuss prospects for important B-anomalies like R(D) and R(D*), as well as other tests of lepton flavour universality.
W1-3 Topics in Medical Physics (DPMB) | Sujets de physique médicale (DPMB) / 2437
The role of physics in Nuclear Medicine
Author: Anna Celler1
1 University of British Columbia
Corresponding Author: [email protected]
The role which nuclear medicine (NM) imaging plays in the diagnosis of many diseases isalready well recognized. In contrast to mostly anatomical modalities (CT, MRI and US), NM is able to provide in-vivo images examining functions of different body parts and organs. Additionally, recent years have witnessed a greatly increased interest in nuclear medicine applications in molecular imaging, targeted radiotherapy and “personalized-medicine” treatments. In my talk, I will introduce the basic principles of nuclear medicine, show examples of its most important clinical applications and discuss some of the latest advances. As any development in medical imaging requires involvement and close collaboration of scientists from many disciplines, the role and contributions of physics and physicists in different aspects of NM imaging will be discussed.
W2-3 Molecular Motors (DPMB) | Moteurs moléculaires (DPMB) / 2438
Molecular machinery: quantifying the energetic cost of control- ling nanoscale biological systems
Author: Steven Large1 Co-authors: David Sivak 1; Raphael Chetrite 2
1 Simon Fraser University 2 Universite de Nice Sophia-Antipolis, Nice, France
Corresponding Authors: [email protected], [email protected]
At microscopic scales, biological systems must maintain a high degree of organization in order to properly function. Ultimately, this organization is achieved by the concerted efforts of a collec- tion of nanoscale molecular machines, protein complexes that perform specific energy-transduction functions within the cell. Quantifying the flows of energy, information, and material through such systems is a central challenge in understanding their dynamics and in vivo operation. What funda- mental physical limits are placed on these nonequilibrium systems? What design principles produce efficient machines? I will discuss our recent efforts, using tools from nonequilibrium thermodynam- ics, to quantify the energetic costs of driving strongly fluctuating systems. In particular, when the controller itself is stochastic (as is the case in molecular machines), dissipation is minimized at a finite speed, implying a thermodynamic benefit to rapid operation.
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T1-1 Soft Matter AM-1 (DCMMP) | Matière molle AM-1 (DPMCM) / 2439
Maxwell’s demon in the real world: Experiments on control, in- formation, and thermodynamics.
Author: John Bechhoefer1
1 Simon Fraser University
Corresponding Author: [email protected]
Just over one hundred and fifty years ago, Maxwell posed a thought experiment now knownas “Maxwell’s demon.” Designed to understand more deeply the nature of the newly formulated sec- ond law of thermodynamics, the demon was to play a long, controversial role in the development of statistical physics. Just two months later, Maxwell’s paper “On governors” gave the first analysis of a feedback system. These two foundational works reflect the fundamental and practical aspects of control. I will present an experiment that unites the two: using feedback to create “impossible” dynamics, we make a Maxwell demon that can reach the fundamental limits to control set by thermo- dynamics. We test—and then extend—Rolf Landauer’s 1961 prediction that information erasure re- quires at least as much work as can be extracted from a system by virtue of information. Using these ideas, we report the first experimental measurement of the functional form for the Gibbs-Shannon entropy function for a system out of thermal equilibrium.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2440
Influence of the neutron pf shell on the structure of28Mg
Author: Jonathan Williams1
1 Simon Fraser University
Corresponding Author: [email protected]
Excited states in 28Mg were studied in an experiment at the ISAC-II facility at TRIUMF to investi- gate the evolution of nuclear shells and search for evidence of the lowering in energy of pf negative parity orbitals predicted near the N = 20 ‘island of inversion’. For the first time 28Mg was investi- gated using a fusion-evaporation reaction [12C(18O,2p)28Mg], leading to preferential population of states at high spin and excitation energy where the influence of the pf negative parity orbitals is expected. Data corresponding to 28Mg was extracted via time coincident identification of protons and gamma rays. Gamma-ray spectroscopy utilized the TIGRESS array at ISAC-II. Charged particles were de- tected and identified using a 38-detector CsI(Tl) scintillator array, which is a subset of therecently completed 128-detector ‘CsI ball’ array developed at SFU as part of the TIGRESS Integrated Plunger (TIP) infrastructure and commissioned at TRIUMF. Lifetime measurements of states populated in 28Mg were performed using Doppler shift methods. 28 π + + Three new excited states of Mg were identified, including candidates for the I = 51 , 61 levels near the neutron separation energy. Lifetime limits of several low-lying states were improved, with the extracted transition strengths suggesting reduced collectivity in the yrast band compared to previous results. Multiple candidates for negative parity states were also observed, including an unusually long-lived state thought to decay by an M2 transition (Iπ = (0, 4)−). The observed level energies are consistent with shell model calculations in the sd and sdpf shells, where negative parity levels arise from single neutron excitation to the pf shell. The data and its interpretation with respect to the lowering of intruder orbitals near the ‘island of inversion’ will be discussed.
R2-5 Detectors for Discovery (PPD/DAPI) | Détecteurs pour la découverte (PPD/DPAI) / 2441
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WITHDRAWN - Performance of Canadian-made muon detectors for the Phase-1 upgrade of the ATLAS detector
Author: Tony Kwan1
1 McGill University
Corresponding Author: [email protected]
For the next two years, the LHC will be shut down while upgrades are being made. These upgrades will result in an increased luminosity which will allow precision measurements of the properties of the Higgs boson and strengthened searches for new particles to be made. In this new high luminosity environment, the Small Wheel muon detectors of the ATLAS detector must be replaced in order to maintain excellent detection and background rejection in the forward regions of the detector. The ATLAS New Small Wheel will partly consist of thin gap chambers, approximately a third of which are being built and tested in Canada. This presentation will provide a brief overview of the construction process of these muon detectors and will describe in detail the performance tests they undergo at McGill University.
T4-2 Plasmas in Different Regimes: Hot and Cold (DPP) | Plasmas en régimes différents: chauds et froids (DPP) / 2442
Ultra-broad bandwidth lasers opening up an easier path to laser fusion
Author: Jason Myatt1
Co-author: Blaine Armstrong 1
1 University of Alberta
Corresponding Authors: [email protected], [email protected]
A reasonably complete understanding of laser-plasma instabilities in directly-driven inertial con- finement fusion has been gained over the past few years by a combination of advances intheory, model development and experiment. It is seen that, by application of laser bandwidth at the 1% level, prospects of ignition on a MJ-scale facility are much improved. I will describe the physical models that have led to these conclusions and the possibility of testing the results in near future. These tests will involve focused laser-plasma interaction experiments using the ultra-broadband laser program underway at the Laboratory for Laser Energetics (University of Rochester, NY, United States). I will also describe recent work that is exploring the use of structured, orbital angular momentum car- rying, laser beams to achieve similar mitigating effects on existing laser facilities that lack abroad bandwidth capability.
W2-1 Creative Education and Partnerships in Learning (DPE) | Éducation créative et partenar- iats d’apprentissage (DEP) / 2443
Citizen Science with the Canadian Collaborative Occultation Net- work
Authors: Terry Bridges1; JJ Kavelaars2
1 Dept of Physics and Astronomy, Okanagan College 2 Herzberg Astrophysics, CADC
Page 29 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Authors: [email protected], [email protected]
I will discuss the CanCON (Canadian Collaborative Occultation Network) project, a citizen science initiative to study Trans-Neptunian Objects (TNOs) in the outer solar system. CanCON involves teachers, students, and amateur astronomers using modest telescopes and digital cameras to deter- mine TNO sizes through precise measurements of the occultations of background stars by the TNOs. Stellar occultations are the only way to directly measure TNO sizes, which provides strong con- straints on their formation and evolution. We have extended the existing RECON (Research and Education Collaborative Occultation Network) by ~10% by adding six stations in the Okanagan Val- ley, extending from Osoyoos to Vernon. These stations are run by high school science teachers and their students, and members of the Royal Astronomical Society of Canada. One of the main goals of CanCON is to engage students and teachers in genuine astronomical research, giving them valuable hands-on experience and a better understanding of STEM subjects. CanCON has been operational since the fall of 2018, and CanCON members have taken part in several campaigns since then. I will discuss results from these campaigns, and our plans for the future. I will report specifically on our successful observation of the occultation of a star bythe TNO nicknamed ‘Goblin’ and the constraint on the size (and thus limit on the albedo) that this provides.
T1-4 Direct Detection of Dark Matter (PPD) | Détection directe de la matière sombre (PPD) / 2444
Dark matter search results from DEAP-3600 at SNOLAB
Author: Simon Viel1
1 Carleton University
Corresponding Author: [email protected]
Dark matter search results and a detailed background model for DEAP-3600 will be presented. DEAP- 3600 is searching for dark matter interactions with a target of liquid argon, shielded from cosmic rays by more than 2 km of rock at SNOLAB in Sudbury, Canada. The spherical detector consists of 3.3 tonnes of liquid argon in a large ultralow-background acrylic cryostat instrumented with 255 photo- multiplier tubes. DEAP-3600 is sensitive to nuclear recoils from dark matter particles, which cause the emission of prompt scintillation light. Backgrounds come from alpha particles on the inner de- tector surfaces, from external neutrons, from argon-39 beta decays, and from trace radioactivity in detector components. This talk details the model for each of these backgrounds, and the analysis techniques that were used to reject them. The latest results from DEAP-3600 demonstrate excel- lent performance for pulse-shape discrimination, event reconstruction, background rejection and sensitivity to dark matter.
T4-2 Plasmas in Different Regimes: Hot and Cold (DPP) | Plasmas en régimes différents: chauds et froids (DPP) / 2445
UV spectroscopy of cold aromatic molecular systems as a diag- nostic of size, functional group, and charge effects.
Authors: Jennifer Noble1; Claude Dedonder1; Christophe Jouvet1
1 Université Aix Marseille
Corresponding Author: [email protected]
Page 30 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
The goal of our recent work is to determine the influence upon the fundamental physical properties of aromatic systems of various factors, notably the role of molecular size, heteroatoms, chemical functionalisation (amino, carbonyl, etc), and charge upon the molecule’s optical properties. These questions are addressed by performing electronic spectroscopy and mass spectrometry on function- alised polycyclic aromatic hydrocarbon (PAH) molecules in varying charge states in a cryogenically- cooled ion trap. Experiments are supported by calculations of ground and excited state geometries and energetics. We illustrate the principle of our combined experimental and theoretical studies using examples of simple functionalised PAHs, from which we derive general laws that can subsequently be applied to larger molecules. This approach allows us to predict the optical properties of molecules too largeto study experimentally and/or theoretically. Noble, J.A.; Dedonder, C.; Jouvet, C., 2015, Astronomy & Astrophysics, 577, 79. doi: 10.1051/0004- 6361/201425493 Noble, J.A.; Dedonder-Lardeux, C.; Mascetti, J.; Jouvet, C., 2017, Chemistry – an Asian Journal, 12, 1523. doi: 10.1002/asia.201700327 Noble, J.A.; Broquier, M.; Grégoire, G.; Soorkia, S.; Pino, G.; Marceca, E.; Dedonder-Lardeux, C.; Jouvet, C., 2018, Physical Chemistry Chemical Physics, 20, 6134. doi: 10.1039/C8CP00218E
W1-8 Probing and controlling matter with light II (DCMMP) | Sonder et contrôler la matière avec de la lumière II (DPMCM) / 2446
Optical Interactions in Graphene
Author: Samantha Scarfe1
Co-authors: Alexei Halpin ; Justin Boddison-Chouinard 1
1 University of Ottawa
Corresponding Author: [email protected]
Two dimensional materials refer to a class of crystals that are atomically thin. Since the isolation of the first 2D material, graphene, the study of such low dimensional systems has attracted widespread attention with the goals of advancing fundamental knowledge and of facilitating the development of next-generation optoelectronic technologies. Crucial to realizing translations to industrial appli- cations is understanding light-matter interactions in 2D materials. In this work, we report on exper- imental progress in investigating optical properties and interactions in the 2D material graphene. In particular, we use terahertz time domain spectroscopy to study the carrier dynamics in graphene. We discuss light-matter interactions in graphene samples that are supported by substrates withdis- tinct optical properties.
T4-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-2 (DPN) / 2447
John D’Auria and his legacy
Author: Richard Casten1
1 Richard
Corresponding Author: [email protected]
John D’Auria had a distinguished career in nuclear structure and astrophysics, including pioneering work on the production and exploitation of beams of exotic unstable nuclei to expand the horizons
Page 31 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
of this field into new realms. His work and influence played a major role in promulgating theexcite- ment of research on unstable nuclei and in propelling today’s proliferation of major facilities for this research in Canada, the US, Europe, and Asia. I have known John since we were graduate students together at Yale in the mid-1960’s. This talk will contain some reminiscences over this half-century plus span of friendship and reflections on his achievements and legacy.
DTP Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPT et finales du concours d’affiches étudiantes (4) / 2448
22 - Mass, light and Gravity in Unitary space-time– (Part II)
Author: zhi-an luan1
1 china petroleum university hua-dong
Corresponding Author: [email protected]
Using the quantum group gravity theory (Double Spectrum digraph), we focus the quantitative re- lationship between inertia masses and rest masses under gravity effects, we found successfully: 1. The quantum coherent parameter in the dual group of a H atom (a proton and an electron) isan exact rational number. The quantum coherent parameter in the triplet group of a neutral baryon (three neutrinos) is also an exact rational number, but the value increases to 3 times. 2. Even so in the different quantum topology context, the conserved-gravity conformal manifold is homeomorphic; the phase change law is same one. We found also that the spinors of fundament particles induce mass growth or drop and control the ratio integer. 3. The derived Gravity-Yang-Baxter Equations rigorously characterize that the above quantum grav- ity behavior of the dual groupoid, the triple groupoid and the multi groupoid, and struct a full equiv- alent quantum gravity Hom-space algebra with same characters. The kernel of quantum gravity structures is the dual or conjugate representation. The rest spectrum structure is deterministic Her- mitian matrix, but the dynamic transition as flip is random non-abelian structure. 4. This unitary gravity time-space ensemble, and its fundamental parameters, are a stable conserved- gravity conformal holography. Then, our revealed dynamics of quantum gravity can same usedfor Planck-scale fundamental particles and macro-scale Universe. From phase transition under gravity, we furtherly proved that our obtained new Newtonian gravitational constant is reliable and true. It means that the explicit exact functions between mass and energy exchange are already obtained. Mass is the space occupied by a graviton at an instantaneous time.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2449
36 - Improving Optical Pumping Methods for Nuclear Beta De- cay
Author: John Behr1 Co-authors: Erin Broatch 2; Anya Forestell 3; Nguyen Lina 4; James McNeil 1; Alexandre Gorelov 1
1 TRIUMF 2 Queen’s University 3 University of Waterloo 4 University of British Columbia
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
To improve our nuclear beta decay asymmetry experiment (which presently has the best percentage accuracy ever achieved (0.35%) [B. Fenker et al. Phys. Rev. Lett. 120 062502 (2018)]), we are trying
Page 32 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
to improve the vector polarization of our laser-cooled atoms from our present 99.1 ± 0.1% [B. Fenker et al. New J. Phys 18 073028 (2016)]. We cycle on and off a MOT, and optically pump 37K atoms with trap off. We use circularly polarized light on the 4S1/2 → 4P1/2 transition, using RF sidebands on a diode laser to excite transitions from both F=1 and F=2 ground states. We test techniques with stable 41K atoms, which have very similar hyperfine splitting to 37K. Upgrades to improve our sys- tematic uncertainties include: preparing the initial atomic state before optical pumping with faster liquid crystal variable retarders, improving the quality of the polarization sign flip, replacing 0.25 mm thick SiC substrate mirrors in front of the β detectors with 0.004 mm unprotected Au-covered kapton to minimize β straggling, and using a 50 µs exposure CMOS camera to explore polarization changes across the trapped atom cloud. We have learned to avoid coherent population trapping effects. Diagnostics of the polarization include the time dependence of the excited state popula- tion after optical pumping light is applied, probed by measuring fluorescence and by nonresonant photoionization. *Supported by NSERC and NRC Canada through TRIUMF
W1-4 Advances in Nuclear and Particle Theory (DTP/PPD/DNP) | Progrès en théorie nucléaire et théorie des particules (DPT/PPD/DPN) / 2450
New Physics In Higgs Decays to Leptons
Author: Daniel Stolarski1
1 Carleton University (CA)
Corresponding Author: [email protected]
As yet, every measurement of the Higgs boson is consistent with the predictions of the Standard Model. I will describe new measurements that can made at the LHC and future colliders in kine- matic distributions. I will focus on the so called “Golden Channel” decay of the Higgs boson with four leptons in the final state. I will show how these measurements can probe both generic devi- ations from the Standard Model, as well as specific models such as supersymmetry. Finally, Iwill describe the “Platinum Channel” decay of the Higgs to as many as eight leptons, and show how ded- icated searches for this spectacular signal can be orders of magnitude more sensitive than current limits.
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2451
Determination of the Physics Reach of the PICO-40L and PICO- 500 Bubble Chamber Dark Matter Detectors
Author: Clarke Hardy1
1 Queen’s University
Corresponding Author: [email protected]
The PICO experiment aims to detect nuclear recoils caused by interactions with WIMP darkmatter using bubble chambers with superheated C3F8. PICO-40L is a detector with a 40-litre active volume currently being installed at SNOLAB, while PICO-500 is a ton-scale detector in the design phase. This talk discusses the physics reach of both detectors, including the discovery limit in thecontext of known backgrounds, the detection floor imposed by coherent elastic neutrino-nucleus scattering, and the potential sensitivity to annual modulations in a dark matter signal.
Page 33 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
R1-1 History of Physics (DHP) | L’histoire de la physique (DHP) / 2452
History of µSR: Applied Particle Physics
Author: Jess H. Brewer1
1 TRIUMF & UBC
Corresponding Author: [email protected]
I will review the history of muon spin rotation/relaxation/resonance (µSR), from its origins in ele- mentary particle physics through its evolution into an essential probe of molecular and materials science, noting how each solution to a problem for one use of muons engendered opportunities for other uses. Canada has played a disproportionate role in this saga, in a series of technological “firsts” that are now indispensable tools in laboratories around the world. After tracing the path from 1957 to the present, I will speculate about possible futures for µSR.
W1-7 Detectors for Particle Physics (DAPI/PPD) | Détecteurs pour la physique des particules (DPAI/PPD) / 2454
Multi-PMTs for NuPRISM/E61
Author: Thomas Hermann Lindner1
1 TRIUMF (CA)
Corresponding Author: [email protected]
Abstract: We are using multi-PMTs (mPMTs) as the photosensors for NuPRISM/E61, the proposed in- termediate water Cherenkov detector for the Hyper-Kamiodande experiment. The Canadian mPMT design has nineteen 3” PMTs enclosed in a water-tight pressure vessel, along with the associated electronics. The 3” PMTs provide excellent spatial imaging of the neutrino-induced Cherenkov light ring. This talk will describe the mechanical design of the mPMT, as well as the design of thedigitiz- ing electronics. Some of the key features of the mPMT design include: i) new Hamamatsu 3” PMTs with improved timing resolution. ii) acrylic dome with gel coupling between the PMTs and the acrylic. iii) FADC digitization in order to handle the expected high rate of neutrino interactions during the J-PARC beam spill. We will describe the results from several different prototype mPMTs we have constructed, as wellas the path towards mass production. Finally we will present the simulated performance of the mPMTs, showing the improvements compared to a detector with larger PMTs.
R1-4 Molecular sciences: outreach, teaching and research (DPE/DAMOPC) | Sciences molécu- laires: rayonnement, enseignement et recherche (DEP/DPAMPC) / 2455
FTIR Synchrotron Spectroscopy of the Lower Modes of Methyl- D3 Mercaptan (CD3SH) – Where is the C-S Stretch?
Authors: Craig W. Beaman1; Ronald M. Lees1; Li-Hong Xu1; Brant E. Billinghurst2
1 University of NB Saint John 2 Canadian Light Source Inc.
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Page 34 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
The infrared Fourier transform spectrum of the lower vibrational modes ofCD3SH has been recorded in the 400-1200 cm−1 region using synchrotron radiation at the FIR beamline of the Canadian Light Source in Saskatoon. Torsion-rotation assignments have been made for a relatively strong parallel band centred at 644 cm−1 and a weaker perpendicular band centred at 727 cm−1. Comparison with the spectra for the normal CH3SH species as well as the analogous CD3OH and CH3OH methanol molecules would suggest an obvious association of the 644 cm−1 band with the C-S stretching mode, with the 727 cm−1 mode likely to be the out-of-plane methyl rock. However, a previous vibrational normal mode analysis [Byler & Gerasimowicz, J. Mol. Struct. 112 (1984) 207-219] showed strong coupling between the C-S stretch and CSH bending modes. They assign the 644 cm−1 band to the latter, and attribute the C-S stretch instead to a supposed feature at688cm−1 that we find no clear evidence for in our spectrum. For normal CH3SH, the CSH bend is very weak and lies between the strong C-S stretch and CH3-rocking bands. A Gaussian quantum chemistry calculation was carried out to explore this mystery, and indeed there is a mode predicted to lie in between our two observed bands with almost vanishing intensity and a reduced mass and effective force constant corresponding closely to those calculated for the C-S stretch for normal CH3SH. This apparent dramatic extinction of the normally very strong C-S stretching band is quite remarkable!
T4-9 Quantum Theory (DTP) | Théorie quantique (DPT) / 2456
WITHDRAWN- Bose-Einstein Condensates as Gravitational Wave Detectors
Author: Matthew RobbinsNone
Co-authors: Niayesh Afshordi ; Robert Mann 1
1 University of Waterloo
Corresponding Authors: [email protected], [email protected], [email protected]
We investigate a Bose-Einstein condensate (BEC) as a gravitational wave detector, and study its sen- sitivity by optimizing the properties of the condensate and the measurement duration. We show that detecting kilohertz gravitational waves is limited by current experimental techniques in squeezing BEC phonons. Future improvements in technology to squeeze BEC states can make them competi- tive detectors for gravitational waves of astrophysical and/or cosmological origin.
R2-4 Testing Fundamental Symmetries II (DTP/PPD/DNP) | Tests de symétries fondamentales II (DPT/PPD/DPN) / 2457
Potential Model Tetraquark Mass Predictions Using Doubly Heavy Diquark Masses from QCD Sum Rules
Authors: Alex Palameta1; Tom Steele1; Derek Harnett2; Robin KleivNone; Steven Esau3
1 University of Saskatchewan 2 University of the Fraser Valley 3 University of Waterloo
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
We use QCD Laplace sum rules to generate mass predictions for vector cc and bb diquarks. We calcu- late the diquark correlator within the operator product expansion to next to leading order, including terms proportional to the four- and six-dimensional gluon and six-dimensional quark condensates. Using these diquark masses as input, a potential model is used to predict the masses of tetraquark states consisting of the these diquarks.
Page 35 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2459
WITHDRAWN - Search for dark sector particles in Higgs boson decays with the ATLAS detector at the LHC
Author: Yu Him Justin Chiu1
1 University of Victoria (CA)
Corresponding Author: [email protected]
The recent discovery of the Higgs boson (h) is an affirmation ofthe Standard Model (SM) of particle physics and concludes several decades of experimental searches. However, the experimental investigation of its properties has just begun. Current measurements of h properties permit the fraction of h decays to Beyond-Standard-Model (BSM) particles to be as high as approximately 30%. These exotic decays are also well-motivated theoretically. Of particular interest is the decay of h to one or two dark sector particles called Zd. This decay occurs in models where h interacts with a dark sector which could have a rich and interesting phenomenology like the SM. A dark sector could naturally address many of the questions left unanswered by the SM. The higher rate of h production resulting from the increased proton beam intensity and energy of the Large Hadron Collider (LHC) in the 2015-2018 data-taking run – combined with strong theoretical motivation and tantalizing hints seen in past searches – makes this decay a promising avenue for the discovery of new physics. I will present results from analysis of the 2015-6 data-set, and present extensions and prospects of this search using the full 2015-8 data-set.
W2-3 Molecular Motors (DPMB) | Moteurs moléculaires (DPMB) / 2460
Design and synthesis of an artificial molecular motor: The Lawn- mower
Author: Chapin Korosec1
Co-authors: Martin J. Zuckermann 2; Michael W.H. Kirkness 3; Nancy Forde 4
1 Simon Fraser Univ 2 Department of Physics and Department of Molecular Biology and Biochemistry, Simon Fraser University, Canada 3 Department of Molecular Biology and Biochemistry, Simon Fraser University, Canada. 4 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Despite the second law of thermodynamics and a harsh thermal environment, molecular motors, among their many talents, are capable of directed motion and long range transport within cells. In this talk I will discuss our approach towards understanding how directed and processive motion is achieved at the molecular scale through the synthesis of an artificial molecular motor comprised of no biological motor components. Our system is designed to achieve directed motion through a burnt-bridges ratchet mechanism whereby it cleaves peptide substrate sites as it moves, thereby inhibiting backwards stepping. The substrate sites are presented to the motor as a ‘lawn’ through the tips of a dense polymer brush; we therefore call our artificial motor ‘the Lawnmower’. I will present our preliminary experimental results of the micron-sized lawnmower on a two-dimensional lawn, as well as present our kinetic Monte Carlo simulations which offer design principles for a nano-scaled version [C.S. Korosec et al., Phys. Rev. E, 98(3), 2018].
Page 36 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2461
83 - AmBe Source Calibrations in Measuring Reactor Antineutri- nos in SNO+ Water Phase
Author: Jamie Grove1
1 Laurentian University
Corresponding Author: [email protected]
SNO+ is a multipurpose neutrino detector located approximately 2 km underground in SNOLAB, Sudbury, Ontario, Canada. The first phase of the experiment, running with ultrapure water, isnow concluded and one of the goals is to detect reactor antineutrinos. Neutrino physics is answering im- portant questions about the structure and behaviour of our universe, including our understanding of neutrino oscillations and masses. During the water phase a radioactive source producing neutrons (241AmBe) was deployed and the calibration data analysed. A key component of an anti-neutrino signal (or neutron) is the identifica- tion of the 2.2 MeV “gamma” from the inverse beta decay neutron capturing on hydrogen. The low trigger threshold allows for a substantial detection efficiency of these neutrons. An in depth analysis of the neutron capture efficiency and transit time between events will allow SNO+ to trigger on and identify antineutrino signals. This presentation the analysis of the AmBe calibration data and the extraction of the neutron capture efficiency for the SNO+ detector with ultrapure water.
M2-2 Fundamental Symmetries (DNP) | Symétries fondamentales (DPN) / 2462
Electron EDM Experiment using Francium at TRIUMF
Authors: Robert Collister1; John Behr2; Benedict Feinberg1; Harvey Gould1; Ulrich Jentschura3; Yan Li1; Charles Munger Jr.1; Hiroshi Nishimura1; Matthew Pearson2; Chris Timossi1
1 Lawrence Berkeley National Laboratory 2 TRIUMF 3 Missouri State University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Dark Matter, neutrino masses, and the excess of matter over antimatter in the universe, areexamples of gaps in our understanding of physics. An electric dipole moment (EDM) of the electron, either large or unobservably small, will be a feature of successful theories of these phenomena, and of other extensions of the Standard Model. Our Electron EDM Collaboration is developing an experiment to search for an electron EDM using francium atoms produced at TRIUMF. Francium is an alkali atom, with its atomic structure well understood, and with its high sensitivity to an electron EDM established accurately from field the- ory. Our experiment will use a francium atomic fountain. A fountain allows the measurement to be done in free space and in free fall, with no collisions with gasses or walls, with no confining lasers or A.C. Stark shifts, and with no applied static or time-varying magnetic fields. There will onlybeastatic electric field between optical state preparation and state analysis, and the optical state preparation and state analysis occur in a region free of both applied magnetic and applied electric fields. In this experiment we can measure our sensitivity to an EDM and even adjust it to zero. We will be able to measure our sensitivity to systematic effects and can make the systematics large toshow that we have them under control. We can also test that any observed effect is linear in the electric
Page 37 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
field and that it reverses with electric field, both of which are definitive signatures of apermanent EDM.
R1-3 Condensed Matter Theory II (DCMMP) | Théorie de la matière condensée II (DPMCM) / 2463
Incompressible Even Denominator Fractional Quantum Hall States in the Zeroth Landau Level of Monolayer Graphene
Author: SUJIT NARAYANAN1 Co-authors: BITAN ROY 2; MALCOLM KENNETT 1
1 SIMON FRASER UNIVERSITY 2 Max Planck Institute for the Physics of Complex Systems
Corresponding Authors: [email protected], [email protected], [email protected]
Incompressible fractional quantum Hall states at even denominator fractions (ν = 1/2, 1/4) have re- cently been observed in experiments in monolayer graphene. We use a Chern-Simons description of multicomponent fractional quantum Hall states in graphene to study these incompressible frac- tional quantum hall states in the zeroth Landau level and suggest variational wavefunctions that may describe them. We find that the experimentally observed even denominator fractions and stan- dard odd fractions (such as ν = 1/3, 2/5, etc.) can be accommodated within the same flux attachment scheme and argue that they may arise from sublattice or chiral symmetry breaking orders (such as charge-density-wave and antiferromagnetism) of composite Dirac fermions. We also discuss pos- sible experimental probes that can narrow down the candidate broken symmetry phases for the fractional quantum Hall states in the zeroth Landau level of monolayer graphene.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2464
Black Holes and the Entangling Structure of Spacetime
Authors: Robert Mann1; Laura Henderson1; Robie Hennigar1; Alexander Smith1; Jialin ZhangNone
1 University of Waterloo
Corresponding Authors: [email protected], [email protected], [email protected]
I describe results that show how black holes affect the entanglement of qubits. Making use ofan approach called entanglement harvesting, which is an operational way to transfer correlations from the quantum vacuum to (idealized) detectors, I show how quantum correlations are affected by the structure of spacetime. This becomes particularly interesting when the spacetime has curvature, and even more so if a black hole is present. A variety of new phenomena occur, including asymmetric time-shift effects, forbidden entanglement islands in parameter space, entanglement inhibition near event horizons, and sensitivity to topology. I shall provide an overview of an ongoing research program in this area along with a description of these and other novel results.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2465
74 - IN SITU MEASUREMENTS OF THE ATLAS JET ENERGY RES- OLUTION USING 13 TeV PP DATA
Page 38 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Benjamin Paul Jaeger1
1 Simon Fraser University (CA)
Corresponding Author: [email protected]
The quarks and gluons produced in proton-proton collisions form collimated sprays of particles, known as jets. They are produced at a very high rate at the Large Hadron Collider (LHC, atCERN in Geneva, Switzerland) and thus are part of almost all interesting pp collision analyses. Due to the complex structure of jets, only a part of their energy can be measured directly in the ATLAS detector. A sophisticated calibration chain is used to correct the energy scale of a jet to that of the initial quark or gluon. An important part of this calibration is to understand the typical range of energy values a given jet can deposit in the detector. This quantifies the Jet Energy Resolution (JER) and is studied in situ by two analyses which are then inputs to a statistical combination. The first analysis measures the JER of anti-kt R = 0.4 jets with transverse momenta up to 1.5 TeV by using well-balanced dijet systems, the second measures the effect of overlapping scattering events - known as pile-up - and detector noise on the JER. This poster focuses on the latter effects, which dominate the JER at low transverse momenta. The expected contribution to the JER from pile-up is extracted from zero-bias data by using the random cones method; the detector noise is estimated in a dedicated Monte Carlo sample with no underlying pile-up activity.
M2-8 General Relativity I (DTP) | Relativité générale I (DPT) / 2466
A connection between linearized Gauss–Bonnet gravity and clas- sical electrodynamics
Author: Mark Robert Baker1
1 University of Western Ontario
Corresponding Author: [email protected]
The oral presentation will consist primarily of a recently published article in International Journal of Modern Physics D entitled “A connection between linearized Gauss–Bonnet gravity and classical electrodynamics”, authored by MR Baker and S Kuzmin. In this article, a connection between a well known gravitational model and classical electrodynamics is derived. Given the excitement among physicists regarding the relationship between the fundamental interactions of nature, this should be an interesting talk for all audiences. A more formal abstract from the article regarding technical contents within is given in the next paragraph, however the talk will be less technical than the contents of the article. Content abstract: A connection between linearized Gauss–Bonnet gravity and classical electrody- namics is found by developing a procedure which can be used to derive completely gauge-invariant models. The procedure involves building the most general Lagrangian for a particular orderof derivatives (N) and a rank of tensor potential (M), then solving such that the model is completely gauge-invariant (the Lagrangian density, equation of motion and energy–momentum tensor are all gauge-invariant). In the case of N=1 order of derivatives and M=1 rank of tensor potential, electrody- namics is uniquely derived from the procedure. In the case of N=2 order of derivatives and M=2 rank of symmetric tensor potential, linearized Gauss–Bonnet gravity is uniquely derived from the proce- dure. The natural outcome of the models for classical electrodynamics and linearized Gauss–Bonnet gravity from a common set of rules provides an interesting connection between two well-explored physical models.
M1-5 Nuclear Astrophysics (DNP) | Astrophysique nucléaire (DPN) / 2467
Mass measurements with the Canadian Penning Trap mass spec- trometer to study the astrophysical r process
Page 39 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Authors: Dwaipayan Ray1; Rodney Orford2; Kumar Sharma1; Jason Clark3; Guy Savard4; Fritz Buchinger2; Gail McLaughlin5; Matthew MumpowerNone; Rebecca Surman6; Adrian Valverde1; Nicole Vassh6; Xinliang Yan7
1 University of Manitoba 2 McGill University 3 Argonne National Laboratory 4 University of Chicago 5 North Carolina State University 6 University of Notre Dame 7 Institute of Modern Physics, Chinese Academy of Sciences
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
About half of the elements in the universe heavier than iron (56Fe) are believed to be produced via the r process (rapid neutron capture process), which is thought to occur during explosive astrophysical events. Due to the short-lived nature of these nuclides and the unique conditions necessary for the occurrence of the r process, our knowledge of this topic is limited. Observations from the recent gravitational wave event (GW170817) and its electromagnetic counterpart at LIGO and VIRGO have reported evidences of neutron star mergers being possible r-process sites. But exactly where the r process occurs in the merging neutron star environment, and whether merging neutron stars can alone account for all the r-process elements are still open questions. Building theoretical models and making reasonable predictions about this r process rely on the availability of mass and other nuclear data for nuclides near the expected r-process path, which is currently available in limited capacity, due to the challenges in producing the rare isotope beams (RIB) necessary for such experiments. With the recent development of a number of advanced RIB facilities, the situation has improved. One such facility is the CAlifornium Rare Isotope Breeder Upgrade (CARIBU), at the Argonne National Laboratory (ANL), which uses the spontaneous fission of a 252Cf source to produce beams of neutron- rich isotopes. The fission fragments are collected, thermalized and extracted as an ion beam,which undergoes multiple stages of purification before being sent to the Canadian Penning Trap (CPT) mass spectrometer. An upgrade to the CPT detection system allowed for the implementation of the novel detection technique, Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR), which permits us to make fast and precise mass measurements of the exotic neutron-rich isotopes nearer to the r-process path. Recently, the masses of a number of rare-earth, neutron-rich nuclides have been measured, which are consistent with the masses needed to reproduce the solar abundance pattern in the rare-earth region for a hot, neutron star merger wind scenario, as determined by reverse engineered Markov Chain Monte Carlo simulations.
T2-1 Soft Matter AM-2 (DCMMP) | Matière molle AM-2 (DPMCM) / 2468
Free energy cost of localizing a single monomer of a confined polymer
Authors: James Polson1; Zakary McLure1
1 University of Prince Edward Island
Corresponding Author: [email protected]
We describe a simple Monte Carlo simulation method to calculate the free energy cost of localizing a single monomer of a polymer confined to a cavity for a localization site on the inside surfaceof the confining cavity. The method is applied to a freely-jointed hard-sphere polymer chain confined to cavities of spherical and cubic geometries. In the latter case we consider localization at both the corners and the centers of the faces of the confining cube. We consider cases of end-monomer localization both with and without tethering of the other end-monomer to a point on the surface. We also examine localization of monomers at arbitrary position along the contour of the polymer. We characterize the dependence of the free energy on the cavity size and shape, the localization
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position, and the polymer length. The quantitative trends can be understood using standard scaling arguments and use of a simple theoretical model. The relevance of these results to the initial stages of polymer translocation through nanopores and polymer dynamics in porous environments is discussed.
M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2469
Thinking of Li-Hong in Outreach Activities from the 5th Grade in Nova Scotia to Kathmandu and the work of IUPAP on Physics for Development
Author: Michael Steinitz1
1 St. Francis Xavier University
Corresponding Author: [email protected]
Li-Hong’s work in outreach was exemplary and we all struggle to carry on her good work. I will try to show some of these attempts: from talking to 5th – graders here, to a 1am Skype lecture toan audience in Pakistan, to making preparations for the World Year of Basic Sciences for Development, as declared by the United Nations. This latter work is being carried out by Commission 13ofIUPAP – Physics for Development.
R1-1 History of Physics (DHP) | L’histoire de la physique (DHP) / 2470
Early Days of the TRIUMF Cyclotron
Author: David Axen1
1 University of British Columbia (CA)
Corresponding Author: [email protected]
By the mid nineteen sixties a vibrant culture of nuclear physics, nuclear chemistry and nuclear medicine was well established across Canada. Immediately following the cyclotron commissioning in 1974 active programs in nuclear physics, pion and muon physics,pion therapy, and isotope pro- duction were initiated. I will describe the configuration of the laboratory and focus on experiments with polarized proton beams as well as the early medical program with negative pions.
W1-2 Teaching for Physics Skills Development (DPE) | Développement d’aptitudes pour l’enseignement de la physique (DEP) / 2471
Using an embedded expert to redesign physics undergraduate lab curriculum and build an intellectual community
Authors: Bei Cai1; Rob Knobel1
1 Queen’s University
Corresponding Authors: [email protected], [email protected]
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The Department of Physics, Engineering Physics and Astronomy at Queen’s University hasem- barked on a journal of transforming its upper year undergraduate lab courses using a backward design strategy. Student learning activities and course assessments have been redeveloped to align with a common set of learning objectives adapted from the recommendations for the Undergraduate Physics Laboratory Curriculum from the American Association of Physics Teachers. Student learn- ing activities and course assessments have been redeveloped giving students a structured way to learn how to design and perform experiments, to analyze data and report on their findings. These activities more closely mimic those of a professional scientist, and lead to improved students satis- faction and performance. This transformation is part of a multi-institution effort to implement and evaluate evidenced-based educational improvement in STEM disciplines. Co-led by an embedded teaching and learning expert and a faculty member, we have built an intellectual community within the department that cares about and frequently shares information on teaching and learning. We describe the approach we used to achieve our transformation goals and share our success stories and lessons learned.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2472
75 - A Neutron calibration system for the Cryogenic Underground TEst facility (CUTE)
Author: Jonathan CorbettNone
Corresponding Author: [email protected]
The Cryogenic Underground TEst facility (CUTE) will be used to test detectors for the SuperCryo- genic Dark Matter Search (SuperCDMS) experiment. SuperCDMS searches for interactions ofdark matter, an unknown form of matter which so far has only been observed through its gravitational effects on astronomical scales, even though it appears to be the dominant form of matterinthe universe. It is important to have a good understanding of the detector’s signal response to be able to inter- pret the data in terms of interactions with dark matter particles. This is achieved by performing calibrations of the detectors with radioactive sources. This poster will focus on the planned neutron calibration system for CUTE.
T4-1 Soft Matter PM-2 (DCMMP) | Matière molle PM-2 (DPMCM) / 2473
Orientationally ordered states of a wormlike chain inside spher- ical confinement
Author: Jeff Z. Y. Chen1
1 University of Waterloo
Corresponding Author: [email protected]
One of the basic characteristics of linear dsDNA molecules is its persistence length, typically of order 50 nanometers. The DNA chain inflicts a large energy penalty if it is bent sharply at that lengthscale. Viruses of bacteria, known as bacteriophage, typically have a dimension of a few tens of nanometers, of similar order of the magnitude as the DNA persistence length. Yet, it is known that a bacterio- phage actively packages viral DNA inside the capsid and ejects it afterwards. The packaging process works under some extreme physical conditions: reduction of the DNA overall conformational en- tropy, competition between the persistence length and the capsid’s size, and the relatively crowded density inside a packaged capsid to accommodate a long DNA chain. Here, adopting a commonly used polymer model known as the wormlike chain, we answer an idealized question: placing a linear
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DNA molecule inside a spherical cavity, what ordered states can we drive from known tools in statis- tical physics? Solving the model in a rigorous field-theory framework, we report a universal phase diagram for four orientationally ordered and disordered states, in terms of two relevant physical parameters.
W1-6 Tests of quark and lepton flavour (PPD) | Tests de saveurs de quarks et leptons (PPD) / 2474
+ + Prospects of search for B → µ νµ decay with the Belle II exper- iment
Author: Andrea Fodor1
1 McGill University
Corresponding Author: [email protected]
Belle II is a next-generation B-factory experiment located at the SuperKEKB e−e+ collider, with the focus on examining the decays of BB¯ meson pairs. The collider is energy-asymmetric, with a planned record-breaking instantaneous luminosity of 8 × 1035 cm−2s−1, 50 times that of its prede- cessor, KEKB. This will enable Belle II to gather 30 times more data than both previous-generation B-factories, Belle and BaBar, combined.
+ + A search for the B → µ νµ decay can probe both the Standard Model and its parameters, and multiple scenarios for New Physics. The Standard Model predicts the branching fraction for this decay mode to be (3.80 ± 0.31) × 10−7. This is a helicity-suppressed decay; the branching fraction depends on the lepton mass. Previously the Belle experiment performed an inclusive search on their full data sample and obtained a 2.4 standard-deviation excess above background level, determining the branching fraction to be −7 (6.46±2.22stat ±1.60syst)×10 . Higher precision and a larger dataset is expected to enable Belle II to make the first observation of this mode. An inclusive search will be performed on the Belle II dataset. A single monoenergetic muon consti- tutes the signal. Signatures from the other B-meson involved in the event will be combined and the missing neutrino from the signal side will be indirectly reconstructed. Various background suppres- sion methods need to be implemented to maximally reduce the continuum and peaking backgrounds. An analysis method is being developed using 1 ab−1 of Belle II Monte Carlo simulation. Reconstruc- tion and background suppression methods will be presented, leading to a discussion of the prospects for this measurement with the Belle II experiment.
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2475
Stress Evaluation of ITK Strip Endcap R0 modules in Coldbox Setup Using FEA Simulations for the ATLAS Detector Phase-II Upgrade
Author: Gabriel Demontigny1
Co-authors: Martin Stegler 2; Filip Nechansky 2; Nikolai Starinski 1; Ingo Bloch 2; Jean-Francois Arguin 1
1 Universite de Montreal (CA) 2 Deutsches Elektronen-Synchrotron (DE)
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
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Planned for the High-Luminosity LHC, the ITK (Inner TracKer) is the upgrade of the current inner detector of the ATLAS apparatus at the Large Hadron Collider (LHC). The ITK is a cylindrically- shaped, all-silicon semi-conductor charged particle tracker, with the ability to run at high rate in a high luminosity and high radiation environment. The ITK is comprised of two different technologies, an inner Pixel detector and an outer Strip detector. To make sure all 20 000 Strip modules are built with a high level of quality, a series of tests are performed for quality control (QC) and quality assurance (QA) of the production. These tests are crucial because once the ITK is installed inthe underground cavern it will not be accessible for approximately 10 years. One of the tests performed as part of QA and QC is the thermal cycling, where modules are monitored while being cooled down and heated up in cycles to temperatures relative to potential operating conditions. These tests will occur in an environmentally controlled enclosure able to hold 4-5 modules simultaneously, known as a cold box. The subject of this work is to study the effect of thermal cycling on future ITKStrip R0 detector modules in terms of induced mechanical stress, and thus inform the design of the cold box. This was performed using a Finite Element Analysis simulation of the thermal cycling process. The first result is that the stress created in the module is mostly due to the vacuum applied tokeep everything in place. Moreover, the maximum stress felt during thermal cycling is highly dependent on the thickness of the vacuum seal used: A thinner seal causes a lower stress. Finally, the stress in the module in our thermal cycling setup is between ∼ 20 MPa and ∼ 100 MPa depending on the selected seal thickness, which is consistent with the stress expected in the final detector design. We can then conclude that our proposed design for the cold box is a good candidate to perform the thermal cycling test.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2476
Unravelling the mechanical properties of collagen with centrifuge force microscopy
Author: Kathrin Lehmann1
Co-authors: Michael W.H. Kirkness 2; Nancy Forde 1; Ignacio Calderon de la Barca 1
1 Simon Fraser University 2 Department of Molecular Biology and Biochemistry, Simon Fraser University, Canada.
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Collagen is the most abundant protein in vertebrates and plays a crucial role for the integrity of stress-bearing tissues, such as tendon and cartilage. All collagen types consist of three α chains, which are coiled about each other into a right-handed triple helix. It is well known that in vivo col- lagens’ mechanical properties provide stability and structure to tissues under a wide range of forces. However, a clear understanding of collagen’s mechanics on the molecular level is still missing. Force- dependent collagen experiments at the molecular level have generally employed magnetic or optical tweezers or atomic force microscopy, costly techniques that are generally low-throughput. The centrifuge force microscope (CFM) that we use for force-dependent structural studies helps to sur- mount these issues [1]. The CFM enables high-throughput single-molecule stretching experiments for force-dependent structural studies on an ensemble of objects using centrifugal force. Our system consists of a miniature light microscope mounted within a rotating device like a centrifuge bucket, with temperature control, live video, long run times (> 2 hours) and a low build cost (< $1000) . Our approach is answering the central question of how an applied force affects the quaternary structure of collagen. Unraveling the mechanical properties of collagen will then help to determine structural and mechanical aberrations associated with collagenopathies and to elucidate how mutations may change collagens’ behaviour under force. [1] Kirkness MWH, Forde NR. Single-Molecule Assay for Proteolytic Susceptibility: Force-Induced Collagen Destabilization. Biophys J. 2018;114(3):570-576.
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T4-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-2 (DPN) / 2477
Rare Isotope Production at ISAC/TRIUMF
Authors: Peter Kunz1; Friedhelm Ames1; Corina Andreoiu2; Jens Lassen1; Valery Radchenko3; Caterina Ramogida2; Paul Schaffer1; Andrew K.H. Robertson3; Fatima Garcia2
1 TRIUMF 2 Simon Fraser University 3 TRIUMF/UBC
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
The continuous 480 MeV proton beam from the TRIUMF H− cyclotron offers a unique potential for the production of rare isotopes via spallation, fragmentation and fission reactions. It was first in- vestigated with the TISOL (Test Isotope Separator On-Line) facility, a project of John d’Auria1. This ground-breaking work cleared the path for the present ISAC (Isotope Separation and ACceleration) and future ARIEL (Advanced Rare IsotopE Laboratory) facilities at TRIUMF2. Currently, the ISAC facility provides a wide range of isotopes3 for basic research in the fields of nu- clear astrophysics, nuclear structure and material science by irradiating targets containing a variety of refractory materials. Reaction products are extracted from the target via diffusion and effusion, ionized and transported through a network of electrostatic beamlines to the experiment. The isotope of interest determines the choice of target material and ion source. A more recent application is the generation of pure exotic isotope samples from proton-irradiated targets for pre-clinical medical research towards therapeutic and diagnostic applications4. While isotopes delivered to online experiments can have half-lives as short as a few milliseconds, radioactive samples collected for offline medical and radiochemistry studies at the ISAC Implantation Station typically have half-lives in the range of hours to days. The focus has been so far on isotopes for targeted alpha therapy (TAT) from composite uranium carbide targets. Samples of 225Ac, 224Ra and 209/211At (generated from 213Fr and 211Fr beams) have been collected. In a new development, alternative isotopes for TAT and Auger Therapy are collected from high-power tantalum metal foil targets which provide high-intensity lanthanide beams3. In a first proof-of-principle test, a 165Tm/Er sample was collected and characterized.
1. J.M. D’Auria, et. al.,The TISOL facility at TRIUMF: operational status at 10 years, NIM B126,7-11 (1997). 2. Dilling, J. ISAC and ARIEL: The TRIUMF radioactive beam facilities and the scientific program. (Springer, 2014). 3. Kunz P, ISAC Yield Database, 2018. URL: http://mis.triumf.ca/science/planning/yield/beam. 4. Hoehr, C. et al. Medical Isotope Production at TRIUMF – from Imaging to Treatment. Physics Procedia 90, 200–208 (2017). 5. Kunz P, et al. Composite uranium carbide targets at TRIUMF. J. Nuc. Mat. 2013;440(1–3):110–6.
M2-5 Nuclear Structure I (DNP) | Structure nucléaire I (DPN) / 2478
Investigating the Nuclear Shell Closure at N=32 in Neutron-Rich 52Ca
Author: Robin Coleman1
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1 University of Guelph
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Nuclei away from the line of stability have been found to demonstrate behavior that is inconsistent with the traditional magic numbers of the spherical shell model that was developed for nuclei close to stability. This has led to the concept of the evolution of nuclear shell structure in exotic nuclei and the neutron-rich Ca isotopes are a key testing ground of these theories. However, there have been conflicting results from various experiments as to the true nature of a sub-shell closure for neutron-rich nuclei around 52Ca. In June of 2018, an experiment was performed at the ISAC facility of TRIUMF; 52K was delivered to the GRIFFIN gamma-ray spectrometer which was paired with the beta-tagger SCEPTAR and the Zero Degree Scintillator auxiliary detectors. Using this powerful combination of detectors, the level scheme of 52Ca populated following the β-decay of 52K has been constructed. Preliminary results from the analysis will be presented and discussed in the context of an N=32 shell closure in neutron-rich nuclei.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2479
WITHDRAWN- Results of the 2018 ATLAS sTGC Beam Tests
Author: Evan Michael Carlson1
1 University of Victoria (CA)
Corresponding Author: [email protected]
After a successful three-year run at 13 TeV, the Large Hadron Collider has paused operation, andwill not circulate beams again until 2021. During this shutdown period, extensive repairs and upgrades will be made to the LHC and its experiments. For the ATLAS experiment, the major upgrade will be to the muon spectrometer in the form of the New Small Wheels (NSW). The NSW will serve in the Level 1 Trigger and will also provide precision tracking of muons. The NSW will consist of two types of gas detectors: Micromegas and Small-strip Thin Gap Chambers (sTGC). The sTGC quadruplets consist of four layers, with each layer composed of pad and strip cathode boards, with high voltage wires in between. In August and October 2018, beam tests of a production sTGC quadruplet were performed in the H8 beamline of the Super Proton Synchrotron at CERN as well as in the Gamma Irradiation Facility (GIF++) on the H4 beamline to characterize detector response and efficiency while operating under different background conditions. This talk will detail the results of multiple aspects of the beam test.
M1-6 Physics in Medicine and Biology 101 (DPMB) | Physique en médecine et biologie 101 (DPMB) / 2480
Applications of Modern Optical Microscopy in Biology
Author: Ian Ross1
1 Nikon Instruments
Corresponding Author: [email protected]
Optical microscopy has long been limited by the diffraction limit of light, but in recent decades many advancements have been made to push beyond this limit to achieve super-resolution microscopy.
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Breakthroughs in optics, mathematics, chemistry, and physics have led to the development of dif- ferent families of super-resolution techniques, each taking a different approach to dealing with the diffraction limit. This talk will highlight the different types of super-resolution microscopy tech- niques currently employed by biologists and discuss some of the advantages and disadvantages to consider when deciding between these techniques.
W2-8 Nuclear Astrophysics II (DNP) | Astrophysique nucléaire II (DPN) / 2481
Commissioning and initial operation of the EMMA recoil mass spectrometer
Author: Matthew Williams1
Co-author: Barry Davids 1
1 TRIUMF
Corresponding Authors: [email protected], [email protected]
The Electromagnetic Mass Analyser (EMMA) is a newly commissioned recoil mass spectrometer located at the ISAC-II facility of TRIUMF. EMMA is designed to separate the products of nuclear re- actions from the unreacted beam, and disperse them according to their mass/charge (A/q) ratio onto detectors located at the focal plane. Utilizing EMMA thus allows for drastically increased sensitivity to study weak reaction channels in the presence of high background. The TIGRESS gamma-ray detec- tor array has now been installed at the EMMA target location, ahead of EMMA’s first experimental campaign that is due to commence during the current beam schedule. An overview of the facility will be presented, along with results from in-beam commissioning tests, and recent progress on cou- pling TIGRESS to EMMA. Details of some approved experiments to be performed during EMMA’s first scientific campaign will also be presented.
M2-9 Magnetism and heavy fermions II (DCMMP) | Magnétisme et fermions lourds II DPMCM) / 2482
A study of spin-pumping in Py/Pt and Py/Pt/Py structures
Authors: pavlo omelchenko1; Erol Girt2; Bret Heinrich2
1 SFU 2 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected]
Spin-pumping is the phenomenon by which a pure spin current can be injected into a non-magnetic metal from an adjacent ferromagnet. Spin-pumping into Pt is of great interest since Pt exhibits large inverse spin Hall effect, important for many spintroincs applications. However, it is not clear that the mechanism of spin-pumping into Pt is well described by standard spin pumping theory consid- ering that Pt is strongly polarized at an interface with a ferromagnet. Evidence of this is observed in literature results, which disagree with their finding; the magnetic damping on Pt thickness is found to be exponential, linear or even discontinuous. To reconcile this we present a clean, experimental system, to test the measure of spin pumping contribution to magnetic damping, α. By studying α in ferromagnet/Pt and ferromagnet/Pt/ferromagnet structures we provide a very rigorous test for spin- pumping into Pt. The induced magnetic moment in Pt also mediates interlayer exchange coupling between the two ferromagnets which results in an in-phase and out-of-phase resonances modes. From the standard spin-pumping framework, this would imply that the two ferromagnets actively communicate with each other via pumped spin-current and would result in very different behaviour of α. Surprisingly, we find remarkable agreement between experimental results and standard spin
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pumping theory which involves interlayer exchange coupling. Our results suggest that the enhance- ment in damping is entirely due to spin-pumping without any contributions from spin memory loss or interface damping due to proximity polarized Pt.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2483
Black holes in a rotating and expanding spacetime
Author: Réjean Plamondon1
1 École Polytechnique de Montréal
Corresponding Author: [email protected]
Black holes in a rotating and expanding space-time In a previous paper [1], we have studied in detail the static non-empty symmetric geometry de- scribed by a metric based on an erfc gravitational potential. Although this new metric provides a consistent set of predictions and interpretations regarding some open problems in the solar system [2], the residual static offset incorporated in the erfc potential can also be reinterpreted in adynamic context. In this paper, we propose, a mathematical equivalence to interpret and provide a plausible dynamic meaning for that constant scalar field. This can be done in two steps. First, the metric can be rewritten in an algebraically equivalent erf symmetric form. Then, interpreting the constant time offset into a spacetime rotation and the constant radial offset into a spacetime expansion, the static metric can be converted into a dynamic one. In other words, the problem is solved by propos- ing a more general axisymmetric geometry which describes a rotating massive body dragging its curved spacetime into a rotation and an expansion. The resulting length element is not invariant under time and azimuth coordinate transformations, which leads to revisit some basic properties of a rotating black hole dragging its spacetime in four dimensions. Although this asymmetric metric does not have any intrinsic singularity, it can give rise to non-singular black holes with a double horizon. [1] Plamondon, R., (2018), General Relativity: an erfc metric, Results in Physics, 9, 456-462. [2] Plamondon, R., (2017) Solar System Anomalies: Revisiting Hubble’s law, Physics Essays, 30(4), 403-411.
M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2484
Li-Hong Xu - A Light in the East
Author: Ronald M. Lees1
1 University of NB Saint John
Corresponding Author: [email protected]
In her academic career, Li-Hong Xu was a source of inspiration and enlightenment to many students, especially young women, both in the university setting and in the larger world. Her research itself was based on light, as she was a molecular spectroscopist, employing a variety of laser systems in her own lab and in recent years utilizing facilities at the Canadian Light Source in Saskatoon, the “brightest light in Canada”. The details of her life and work present a fascinating picture of adynamic and determined woman who embraced a wide variety of challenges and rose to prominence in her international and national research communities, her university teaching community, and her wider home community in Saint John and Atlantic Canada. Here we will touch on some of her notable achievements and on activities she undertook in teaching and community outreach. Some of these were the innovative “Party Physics” in her first–year course, the “Physics Circle” she introduced for
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girls at the Public Library to arouse their interest in physics and science, and her demonstration shows where she would recruit keen girls from her class to show off a variety of physics “Magic” to an admiring and frequently amazed public at Science Fairs and the annual UNBSJ school Math competitions and open houses.
T4-10 Thinking Outside the Box (DPE) | Penser hors de la boîte (DEP) / 2485
What Is the Condition for Conservation of Momentum?
Author: Michael Chen1
Co-author: Andrew DeBenedictis 1
1 Department of Physics, Simon Fraser University
Corresponding Authors: [email protected], [email protected]
When teaching the law of conservation of linear momentum to first-year university or senior high school students, it is quite popular to use the term “isolated system” to describe the condition of the conservation law. That is, the law of conservation of momentum is stated as that the momentum of an isolated system is constant. Our investigation suggests that the term isolated system, though useful if properly defined, can cause confusion, and furthermore may create a conceptual barrierin understanding and applying the law of conservation of momentum. Keywords: Physics Education, Conservation of momentum, isolated system
W1-6 Tests of quark and lepton flavour (PPD) | Tests de saveurs de quarks et leptons (PPD) / 2486
Measuring the anti-muon-neutrino induced charged-current co- herent pion production using the T2K near detector
Author: Mitchell Yu1
1 York University
Corresponding Author: [email protected]
A neutrino(anti-neutrino) can interact with the target nucleus as a whole (coherent scattering, COH) and produce a pion in the final state. This process can be mediated by either a Z (neutral-current, NC) or a W boson (charged-current, CC). In both cases, produce a pion, and the target nucleus recoils intact and is generally unobservable in neutrino detectors. Thus, NC-COH is one of the main backgrounds for electron neutrino tagging in water Cherenkov detectors. Measurement of CC-COH can help to constrain the modeling of coherent pion production in neutrino event generators. The Tokai-to-Kamioka (T2K) experiment published the first measurement of CC-COH in thesub- GeV neutrino energy region with neutrino flux of 0.6GeV energy on the carbon target. Thistalk will focus on the analysis of CC-COH with T2K’s anti-neutrino beam and a statistical update to the neutrino CC-COH measurement. Plans for calculating a neutrino/antineutrino CC-COH ratio will also be discussed.
T2-9 Fields and Strings I (DTP) | Champs et cordes I (DPT) / 2487
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Towards an Asymptotically Safe Standard Model
Author: Zhi-Wei Wang1
Co-authors: Tom Steele 2; Robert Mann 1
1 University of Waterloo 2 U of Saskatchewan
Corresponding Authors: [email protected], [email protected], [email protected]
In this talk, I will discuss how to realize an asymptotically safe Standard Model by using the large number of flavours (N_f) techniques. This framework also opens the way to various safe extensions of the Standard Model. The first asymptotically safe Pati-Salam model and trinification model will also be discussed.
R1-1 History of Physics (DHP) | L’histoire de la physique (DHP) / 2488
Physicists and the first Pugwash Conference in 1957
Author: David Fleming1
1 Mount Allison University
Corresponding Author: [email protected]
In 1955, a number of prominent scientists, alarmed by the danger of nuclear weapons, signed a public statement which became known as the Russell-Einstein Manifesto. This document urged scientists to take a more active role in assuring nuclear weapons would not be used again, and recommended a meeting of international scientists to open dialogue on the topic. The first such meeting, which included high profile physicists from around the world, took place in the small village of Pugwash, Nova Scotia in July 1957. Since this initial meeting, the Pugwash Conferences on Science and World Affairs have grown to become an international organization with a variety of national chapters. The Pugwash Movement has been key in facilitating discussions on global-scale threats to humanity. The 1995 Nobel Peace Prize was awarded jointly to the Pugwash Conferences and to physicist (and founding member) Joseph Rotblat “for their efforts to diminish the part played by nuclear armsin international politics and, in the longer run, to eliminate such arms”. My talk will examine the history behind the first Pugwash Conference and take a look at some of the physicists who participated in the meeting. *note for abstract review: although this abstract may not fit directly under the theme of “history of the development of physics research and instruments”, it is hoped that the topic is of sufficient interest to the history of physics to represent an excellent fit for the session.
W2-7 Condensed Matter Theory I (DCMMP) | Théorie de la matière condensée I(DPMCM) / 2489
Strongly-coupled superconductivity from quantum cluster approaches
Author: David Sénéchal1
1 Université de Sherbrooke
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Corresponding Author: [email protected]
Unconventional superconductors, such as high-Tc cuprates, strontium ruthenate and twisted bilayer graphene, are likely driven towards their state by strong electron-electron repulsion, instead of the classic electron-phonon interaction. Theoretical modeling of these materials may accordingly be based on the Hubbard modelorby its multi-band variations. Few theoretical approaches can deal with the strong interactions in- volved. In this talk I will review cluster approaches to strongly correlated superconductivity and competing orders. These include Cluster Dynamical Mean Field Theory and the Variational Cluster Approxi- mation. The discussion will focus on zero-temperature results obtained via an exact-diagonalization solver. Applications to high-Tc cuprates will be described, including related phenomena such as the pseudogap and charge order. Triplet superconductivity on the graphene lattice will also be discussed, as well as applications to twisted bilayer graphene.
W1-7 Detectors for Particle Physics (DAPI/PPD) | Détecteurs pour la physique des particules (DPAI/PPD) / 2490
Introduction to 3D Digital SiPM and Latest Results for Particle Physics
Authors: Jean-Francois Pratte1; Simon Carrier1; Audrey Corbeil Therrien2; Keven Deslandes1; Pascal Gendron1; Michel Labrecque-Dias1; William Lemaire1; Frédéric Nolet1; Samuel Parent1; Charles Richard1; Nicolas Roy1; Tommy Rossignol1; Gabriel St-Hilaire1; Frédéric VachonNone; Fabrice Retiere3; Henri Dautet1; Réjean Fontaine1; Serge A. Charlebois1
1 Université de Sherbrooke 2 SLAC 3 Triumf
Corresponding Author: [email protected]
Conventional analog SiPMs are increasingly used in medical imaging such as positron emission to- mography (PET) and are good candidates for particle physics detectors such as nEXO and DarkSide. A new generation of photon counting device called 3D digital SiPM (3DdSiPM) addresses the main limitations of conventional SiPM and offers even more flexibility and signal processing capability. The concept is to integrate in the vertical axis an array of single photon avalanche diodes (SPAD) stacked over an array of microelectronics readout channels and digital signal processing. At Uni- versité de Sherbrooke, we are working on the SPAD implementation, the 3D bonding process and two flavours of CMOS microelectronic readouts. The first flavour is geared toward verylowpower consumption. It is dedicated to large-scale detectors for double beta decays neutrinos less and dark matter studies where the 3DdSiPMs are operated directly in liquid xenon or liquid argon. Thesecond version of the readout is designed for extremely low single photon timing resolution, with the goal to reach sub 10 ps FWHM. This 3DdSiPM is of interest for PET using prompt photon emission or liquid xenon as scintillator. It is also relevant to study scintillation mechanisms and prompt photon emis- sion processes of various materials. Moreover, we have recently started a new project for quantum key distribution between ground and satellite. The measured timing jitter of this readout integrated circuit is 18 ps RMS. The SPAD array measurement shows 50% photo detection efficiency at450nm. Also, we are working at enhancing their VUV sensitivity above 25% at 175 nm (LXe) and to allow direct detection of LAr scintillation light. The SPAD also exhibits a single photon timing resolution of 23 ps FWHM. At the conference, an overview of the systems and measured performances from the SPAD to the CMOS readout will be presented and discussed.
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2491
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Elastic Properties of Natural Biotite Crystals by Brillouin Spec- troscopy
Authors: Dillon Hanlon1; Todd Andrews1 Co-author: Roger Mason 2
1 Department of Physics and Physical Oceanography, Memorial University of Newfoundland 2 Department of Earth Sciences, Memorial University of Newfoundland
Corresponding Authors: [email protected], [email protected]
Experiments were performed on natural crystals of biotite in an attempt to quantify the effects of impurities on acoustic phonon behaviour and elastic properties in this mica series. Electron probe microanalyzer(EPMA) was used to quantify the chemical compositions of biotite with differing con- centrations of Fe and Mg. Brillouin light scattering spectra of these samples contained peaks dueto pure transverse, quasi-transverse and quasi-longitudinal acoustic phonon modes. Analysis of these spectra permitted determination directional dependence of the velocities of these modes in theac and bc crystallographic planes as well as the elastic constants C11, C22, C33, C44, C55, C66, C13, C15, C23, C25, C35, and C46. In general, the acoustic mode velocities decrease with increasing Fe concentration. The values of some elastic constants also appear to show a dependence on impurity and concentration.
W1-2 Teaching for Physics Skills Development (DPE) | Développement d’aptitudes pour l’enseignement de la physique (DEP) / 2492
Integration and Evaluation of Coding in First Year Integrated Physics and Calculus Courses.
Author: Matt Steffler1 Co-authors: Martin Williams 1; Michael Massa 1
1 University of Guelph
Corresponding Authors: [email protected], [email protected]
It has been recognized that computational skills are essential for the modern physicist, whether as a third “branch” of physics alongside experimental and theoretical, or as a toolset that is fundamental to the work of both theorists and experimentalists. In recognition of this, both the American Asso- ciation of Physics Teachers and the American Physical Society have issued calls for computational instruction to be included at an appropriate level in undergraduate physics curricula. We selected two consecutive first year integrated physics and calculus courses aimed at physical science majors to create situations where students were learning physics and computing together. Python coding, via the Jypyter Notebooks system, was introduced in a carefully scaffolded system in several of the courses’ laboratory exercises, and was assigned to students in a Modeling Theory case-study assign- ment in each course. We analyze students’ coding proficiency, both perceived (through surveys and discussions) and actual (through coding achievement on the assignments) and evaluate whether students’ familiarity, comfort, and skill in computational physics have been elevated through these exposures.
DPE Poster Session & Student Poster Competition Finals (5) | Session d’affiches DEP et finales du concours d’affiches étudiantes (5) / 2493
10 - Engaging reflective thinking during exam-like situations: Slow- ing students down on short-answer questions increases perfor- mance
Page 52 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Authors: Joss Ives1; Jared Stang1
1 University of British Columbia
Corresponding Authors: [email protected], [email protected]
In a series of experiments designed to engage students in reflective thinking in exam-like situations, we test the effectiveness of two different interventions in improving student performance on specific short-answer questions. These interventions (1) ask students to explain their answer after answering a short-answer question, or (2) pair questions together for concepts that students frequently confuse for each other. For both interventions we demonstrate that we are able to increase student perfor- mance on those specific questions. These results have implications for the design of short-answer physics questions in learning and assessment situations.
T4-10 Thinking Outside the Box (DPE) | Penser hors de la boîte (DEP) / 2494
Engaging reflective thinking during exam-like situations: Slow- ing students down on short-answer questions increases perfor- mance
Authors: Joss Ives1; Jared Stang1
1 University of British Columbia
Corresponding Authors: [email protected], [email protected]
In a series of experiments designed to engage students in reflective thinking in exam-like situations, we test the effectiveness of two different interventions in improving student performance on specific short-answer questions. These interventions (1) ask students to explain their answer after answering a short-answer question, or (2) pair questions together for concepts that students frequently confuse for each other. For both interventions we demonstrate that we are able to increase student perfor- mance on those specific questions. These results have implications for the design of short-answer physics questions in learning and assessment situations.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2495
28 - Axial EBIC oscillations at core/shell GaAs/Fe nanowire con- tacts
Author: Mingze Yang1 Co-authors: David Dvorak 2; Karin Leistner 3; Christine Damm 3; Simon Watkins 4; Karen Kavanagh 4
1 Simon Fraser University 2 UBC 3 IFW Dresden 4 SFU
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], c.damm@ifw- dresden.de, [email protected]
Electron beam induced current (EBIC) measurements were carried out in situ in the scanning elec- tron microscope on free-standing GaAs/Fe core–shell nanowires (NWs), isolated from the GaAs substrate via a layer of aluminum oxide. The excess current as a function of the electron beam en- ergy, position on the NW, and scan direction were collected, together with energy dispersive x-ray
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spectroscopy. A model that included the effects of beam energy and Fe thickness predicted anaver- age collection efficiency of 60%. Small spatial oscillations in the EBIC current were observed, that correlated with the average Fe grain size (30 nm). These oscillations likely originated from lateral variations in the interfacial oxide thickness, affecting the resistance, barrier potentials, and density of minority carrier recombination traps.
M1-2 Exploring the energy frontier (PPD) | Explorer la frontière d’énergie (PPD) / 2496
Improvement of missing transverse momentum reconstruction for ATLAS experiment at LHC
Author: Zhelun Li1
1 University of Victoria (CA)
Corresponding Author: [email protected]
The performance of missing transverse momentum (MET) determination using a new algorithm is presented. The peak luminosity of the LHC in 2017 data-taking reached a new record of 1.90 · 1034 cm−2 s−1 and it is aiming to achieve higher luminosity after up-coming upgrades of the Large Hadron Collider (LHC) and produce a larger number of interactions per bunch crossing < µ >. Such increase in pile-up interactions will pose a challenge to the existing MET algorithm. The new pile-up fit (PUfit) algorithm is designed to reduce the sensitivity of the MET to pile-up collisions. The algorithm was tested in di-muon decays of the Z boson in 13 TeV ATLAS data. TheZbosonwas used as an imaginary source of MET to test and calibrate the algorithm. The estimated resolution and scale were then compared to that produced by the standard offline algorithm. Results of these comparisons will be presented and discussed in this talk.
M1-2 Exploring the energy frontier (PPD) | Explorer la frontière d’énergie (PPD) / 2497
The search for exotic dilepton signatures in the full LHC Run-2 dataset collected with the ATLAS detector
Author: Etienne Dreyer1
1 Simon Fraser University (CA)
Corresponding Author: [email protected]
After running for over three years at a world-record collision energy of 13 TeV, the Large HadronCol- lider (LHC) completed its Run-2 dataset last December. This new dataset offers an unprecedented opportunity to test a wide range of theories which, if true, would address questions that remain unanswered in the otherwise well-established Standard Model of particle physics. However, such gains in explanatory power hinge entirely on the existence of new fundamental quantum fields and their associated particles whose decay signatures can be recorded in the ATLAS detector. In partic- ular, a decay signature involving a pair of high energy electrons or muons (dilepton) is theoretically and even historically well motivated, and has recently been investigated using the leverage of the full Run-2 dataset. In my presentation I will touch on these theoretical motivations and then detail the procedure and results of the latest search for exotic particles producing dilepton signatures in data collected with the ATLAS detector. I will also explain what the findings represent in the wider context of searches at the LHC and how they help guide theoretical developments toward a better description of particle physics.
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W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2498
Quantum Diffractive Collision Universality and the Quantum Pas- cal
Authors: James Booth1; Pinrui Shen2; Roman Krems2; Kirk Madison2
1 BCIT 2 UBC
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Cold atoms have revolutionized experimental physics, leading to breakthroughs ranging from the creation of new states of quantum matter to the redefinition of the primary SI units. In our work,we have been studying collisions between cold Rb atoms held in a magnetic trap and room temperature background gas particles. These collisions are particularly interesting owing to the fact that they include long-range (high impact parameter and high angular momentum) interactions which im- part very little momentum to the trapped atoms, so-called quantum diffractive (QD) collisions. Cold, trapped atoms have low momenta and large deBroglie wavelengths, making them excellent detec- tors for quantum diffractive collisions. The small momentum changes are measured through theloss rate of the “sensor” atoms from shallow magnetic traps, whose depths, U, can be varied. Namely, the variation of the loss rate with trap depth is a momentum spectrometer. In this talk, I will present our recent discovery of a new class of universality which describes the velocity-averaged loss rate coefficient associated[ with( QD )collisions,] ∑ j U ⟨σlossv⟩ = ⟨σtotv⟩ 1 − βj . j Ud 2 Here, ⟨σtotv⟩ is the velocity averaged total cross-section, Ud = 4π¯h vp/(mt⟨σtotv⟩) is a charac- teristic energy scale for quantum diffractive collisions, mt is the mass of the trapped atom, and vp is the most probable speed for the room temperature background particle. The βj coefficients are universal, characterising the nature of the QD collision interaction. That is, each form of long-range n interaction, −Cn/R , are a different class of universality with unique βj. This universality has been demonstrated for atom-atom (Rb-X, X = He, Ar, Xe) and atom-molecule (Rb-X, X = H2,N2, CO2) col- 6 lisions, characterized by a long range potential of the form −C6/R . This breakthrough has allowed us to define the “quantum pascal”, a definition of the Pascal basedonthe measured velocity average total collision cross-sections and on immutable atomic properties.
R2-5 Detectors for Discovery (PPD/DAPI) | Détecteurs pour la découverte (PPD/DPAI) / 2499
Goals and Scope of the Light-Only Liquid Xenon Project
Author: THOMAS MCELROY1
1 McGill University
Corresponding Author: [email protected]
The Light-Only Liquid Xenon (LOLX) project aims to study the properties of light emission inliquid xenon (LXe). Investigating both the scintillation and Cherenkov light emission, LOLX will explore the abilities of single-phase liquid xenon detectors as particle detectors and in medical imaging de- vices. The first phase of the LOLX detector consists of 24 Hamamatsu VUV4 Silicon photomultipliers (SiPMs), giving a total of 96 channels arranged in an octagonal cylinder. Covering 92 of the channels are 225nm high pass filters which block the Xe scintillation light, allowing for independent measure- ments of the long-wavelength Cherenkov and VUV scintillation light. The initial goal of LOLX is to measure the Cherenkov and scintillation yields from 90Sr beta-decays and 210Po alpha-decays, using this to validate optical transport simulations using GEANT4 and verify measurements of the VUV light reflectivity being performed at TRIUMF. Future phases of the project will upgrade tofast waveform digitizers with 10 ps timing accuracy and 3D integrated digital SiPM (from U.Sherbrooke) to further investigate the prompt time characteristics of Xe scintillation and investigate the use of
Page 55 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
timing to separate the Cherenkov and scintillation signals. LOLX is also investigating the use of 3D printed plastics for use in vacuum and cryogenic applications. This talk will give an overview of the LOLX project and its current state.
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2500
A Supernova Calibration Source for SNO+
Author: Janet Rumleskie1
1 Laurentian University
Corresponding Author: [email protected]
Only one supernova neutrino burst has ever been detected, and the detection of additional neutrinos from galactic core-collapse supernovae are expected to provide insight on the supernova explosion mechanism. One candidate for detecting supernova neutrinos is SNO+, a multipurpose ultra-low background particle detector. Within SNO+, a galactic supernova neutrino burst is expected to generate an unprecedented rate. Thus, it is necessary to stress-test and optimize the SNO+ data acquisition and electronics so that a supernova signal can be reliably read out. For this purpose, a Supernova Calibration Source is under development to mimic the light expected from supernova neutrino interactions [1]. Using one-dimensional simulated supernova neutrino datasets [2, 3], light profiles representing neutrino interactions are calculated and realised using a laser diode light source delivered into the detector via fibre optics and a deployed light diffuser. This talk will focus onthe software conversion of neutrino datasets to light profiles, which define the light intensity andtiming in the calibration source. [1] C. Darrach. The SNO+ Supernova Calibration Source: Development and Testing. MSc Thesis, Laurentian University, Sudbury, ON, Canada (2016) [2] L. Hüdepohl, B. Müller, H.-T. Janka, A. Marek, and G. G. Raffelt. Phys. Rev. Lett. 104, 251101 (2010) [3] A. Mirizzi et al. Rivista del Nuovo Cimento Vol. 39 N. 1-2 (2016)
T2-9 Fields and Strings I (DTP) | Champs et cordes I (DPT) / 2501
Dark matter from Kalb-Ramond gauge symmetry
Authors: Rainer Dick1; Andrii Dashko2
1 University of Saskatchewan 2 Taras Shevchenko National University of Kyiv
Corresponding Author: [email protected]
We point out that the Kalb-Ramond field of string theory can induce electroweak dipole dark matter, although the dark matter constituents of the dipoles do not carry weak charges. We also showthat the model is compatible with direct search constraints from electron recoils. However, the recoil cross sections are above the neutrino floor and should be testable in future experiments.
W2-9 Hadronic Physics (DNP/DTP) | Physique hadronique (DPN/DPT) / 2502
The GlueX Experiment: A Search for Exotic Matter
Page 56 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Papandreou Zisis1
1 University of Regina
Corresponding Author: [email protected]
A long-standing goal of hadron physics has been to understand how the quark and gluon degrees of freedom that are present in the fundamental QCD Lagrangian manifest themselves in the spectrum of hadrons. The GlueX Experiment’s place in the global spectroscopy program is complementary to efforts at other facilities: using 8-9 GeV linearly polarized photons at Jefferson Lab, GlueX isfocusing on the exploration of the light-quark domain, potentially accessing hybrid mesons with exotic JPC quantum numbers produced in photon-proton reactions. The experiment has recently finished its first phase of running having collected 280 billion triggers, with 20% of the data in active analyses. The key features and results of this compelling physics program will be presented with emphasison the beam asymmetry ratio between the eta-prime and eta mesons as it is sensitive to the exchange processes in the resonance production mechanism.
M1-7 Identity and Physics Education (DPE/CEWIP) | Identité et enseignement de la physique (DEP/CEFEP) / 2503
Assessing affective contributions to gender inequalities in intro- ductory physics courses
Authors: Jared Stang1; Emily Altiere1; Joss Ives1
1 University of British Columbia
Corresponding Authors: [email protected], [email protected]
Across several years of Physics 100 and Physics 101, two large introductory physics courses at UBC, a consistent pattern has emerged: On exams and diagnostic tests for nearly 3000 students, femalestu- dents underperform relative to their male peers. The existence of this performance gap is consistent with the science education literature. However, a focus on performance may be missing important details. Recent research has shown that affective outcomes—such as self-efficacy and belonging— may also suffer gender gaps and that differences in these may mediate learning. Here, weexplore the gender inequalities that exist in our introductory physics course in both the cognitive and affec- tive domains. Incoming knowledge was measured with the Force Concept Inventory (FCI), outgoing performance was measured with the FCI and the course exam, and we adapted survey tools to mea- sure student self-efficacy and level of test anxiety. We report the inequalities that exist and analyze correlations between them to understand what the causes within our courses might be. The ultimate goal is to suggest interventions that reduce the gender gap and create a more equitable classroom for all.
W2-2 Quantum Information (DAMOPC/DTP) | Information quantique (DPAMPC/DPT) / 2504
Experimental demonstration of a quantum optics solution to the partition problem
Author: Felix Hufnagel1
Co-authors: Avishy Carmi 2; Ebrahim Karimi 1
1 University of Ottawa 2 Ben-Gurion University of the Negev
Page 57 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Authors: [email protected], [email protected], [email protected]
Many computational problems require extensive processing or memory resources which can render solving them impossible when using known computer algorithms. An interesting problem in num- ber theory is that of determining whether a set of integers can be separated into 2 subsets in which the sum of the integers in each subset is equal. This is often referred to as the partition problem, which is NP complete. Moreover, counting the number of possible partitions is known to be in #P (sharp P). It has been shown that the partition counting problem can be reformulated as evaluating an integral up to an accuracy of n binary digits, where n is the number of integers. Computing this integral would generally not give us any speedup over a brute force approach to finding the partitions. However, we prove that upon particular encoding of this problem followed by an evalu- ation the Fourier transform and a decoding process we can effectively find the number of partitions. Therefore, we can experimentally encode our problem in the position space of an optical fieldand allow it to propagate to the far field to make a later measurement in momentum space, thus applying the Fourier transform. We use a spatial light modulator to show that this optical setup can have an advantage over solving this problem computationally. Furthermore, we show that if we prepare a quantum state of light, we can further speed up the computation using quantum tomography. Thus, this scheme is a unique display of utilizing a physical system alongside with quantum measurement techniques to solve a hard computational problem.
R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2505
E61 Status and Sensitivity Studies
Author: John Walker1
1 University of Winnipeg
Corresponding Author: [email protected]
E61 is a proposed intermediate water Cherenkov detector (IWCD) for the future Hyper-Kamiokande (Hyper-K) long baseline neutrino experiment. The detector can be raised/lowered to span a contin- uous 1-4 degree off-axis range, relative to the neutrino beam centre, in order to make a novel mea- surement of the interaction rate as a function of neutrino energy. In this way E61 will constrain the neutrino interaction model, which is the dominant uncertainty for Hyper-K; also by having the same interaction medium as the far detector we will also reduce the dependence of our analysis on the neutrino interaction model. Gadolinium doping may also be used to measure neutron emissions from neutrino interactions, enabling a statistical separation of neutrino and antineutrino events and reduction in wrong-sign background. This talk will describe the detector design, R&D, and progress towards construction. The sensitivity of the detector to different physics measurements will be demonstrated, in particular the abilityto constrain energy bias due to incorrect modelling, the electron neutrino cross-section which is critical to the measurement of CP violation, and the resultant sensitivity for a CP violation measurement at Hyper-K.
M1-1 Test of Fundamental Physics with Atoms (DAMOPC) | Tests de physique fondamentale avec des atomes (DPAMPC) / 2506
Tests of fundamental physics with trapped antihydrogen
Author: Tim Tim Friesen1
Co-author: The ALPHA collaboration
1 University of Calgary
Page 58 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
Antihydrogen, as the simplest purely antimatter atomic system, is a natural candidate for testing fundamental symmetries between matter and antimatter. For example, CPT symmetry predicts that the spectra of hydrogen and antihydrogen should be identical. By making precise measurements of antihydrogen’s transition frequencies, and making comparisons to high precision measurements in hydrogen, we have an excellent test of CPT symmetry in the atomic sector. The primary transitions of interest are the 1S – 2S and ground-state hyperfine transitions, which are known to 4.2 parts in 1015 and 7 parts in 1013 in hydrogen, respectively. In addition, the fact that antihydrogen is electrically neutral means it can be used as a probe of the gravitational interaction between matter and antimatter. If the weak equivalence principle holds then the gravitational mass of antimatter should be identical to that of matter but so far there have been no direct free-fall style experiments to test this.
The ALPHA collaboration at CERN aims to test these principles using antihydrogen atoms confined in a magnetic trap. The ALPHA experiment has developed antihydrogen trapping techniques that allow the simultaneous confinement of more than 1000 antihydrogen atoms. This has led to detailed measurements of antihydrogen’s 1S – 2S, 1S – 2P, and ground-state hyperfine transitions. In addition, ALPHA has recently built a new vertical antihydrogen trapping apparatus for a direct measurement of the gravitational free-fall of antihydrogen. In this talk, I will present a general overview of ALPHA’s apparatus, techniques, and results. Partic- ular focus will be placed on ground-state hyperfine spectroscopy and magnetometry for precision spectroscopy and gravity measurements on trapped antihydrogen.
M1-5 Nuclear Astrophysics (DNP) | Astrophysique nucléaire (DPN) / 2507
Investigation of High-Lying (,) Resonances in 22Ne via High- Resolution Gamma Ray Spectroscopy in Inverse Kinematics
Author: Beau Greaves1
Co-authors: Dennis Muecher 2; Stephen Gillespie 3
1 University of Windsor 2 University of Guelph 3 TRIUMF
Corresponding Authors: [email protected], [email protected]
In asymptotic giant branch (AGB) stars, 22Ne plays an important role in several nucleosynthesis processes, with its production competing with the synthesis of 19F through the so called ‘poisoning reaction’, and the following transfer into 25Mg acting as the main neutron sources for the heavy element s-process, affecting the reaction rates of numerous isotopes. In this contribution, we discuss a recent neutron transfer experiment done at TRIUMF in November 2018, directly populating 22Ne, allowing for high resolution measurements of the resonance ener- gies with the SHARC silicon detector, coupled to the HPGe detector array TIGRESS for accurate measurement of the characteristic gamma rays. We will then present the method of using the angu- lar distribution of these newly measured gamma rays to determine the spins of the resonance states, allowing for further constraint on the reaction cross-section.
W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2508
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Time-Dependent Artificial Gauge Fields in Ultracold Quantum Gases
Authors: Logan Cooke1; Benjamin Smith1; Taras Hrushevskyi1; Lindsay LeBlanc1
1 University of Alberta
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Here, we study the effects of various time-dependent artificial gauge fields on a Bose-Einstein con- densate (BEC) of rubidium-87 atoms. In particular, we perform numerical simulations of a quasi-3D BEC in a harmonic trap subjected to artificial gauge fields. We study oscillating synthetic electric fields, synthetic magnetic fields, and combinations thereof; we look at the contributions frominter- actions within the gas as well as other various system parameters. Simulations of spinor-BECs and progress towards experimental implementations are also discussed. This work is expected to further expand the quantum simulation toolbox, leading to new venues in quantum simulation.
T2-7 Nobel Prize Session (DAMOPC) | Session de prix Nobel (DPAMPC) / 2510
Strong fields for spectroscopy
Author: TJ Hammond1
1 University of Windsor
Corresponding Author: [email protected]
High harmonic spectroscopy has been used for decades for sub-femtosecond resolution of molecular dynamics and attosecond measurements of electronic configurations. Recently, these ideas have been transferred to condensed matter to understand strong field processes in semiconductors and dielectrics. In developing these attosecond techniques, we have discovered that we can fully mapthe waveform of an ultrashort pulse, or create a broad spectrum sensor for THz radiation. In this talk, I will discuss the possibilities for spectroscopy using some of these attosecond technologies.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2511
Stable negative mass solutions in de Sitter spacetime
Authors: Matthew Johnson1; Manu Paranjape2; Antoine Savard2; Natalia Tapia-Arellano3
1 York University/Perimeter Institute 2 Université de Montréal 3 Université de Montréal/Universidad de Santiago
Corresponding Authors: [email protected], [email protected], [email protected], an- [email protected]
We demonstrate the existence of stable, non-singular, negative mass solutions in de Sitter space- time. The solutions correspond to the exact negative mass Schwarzschild-de Sitter spacetime onthe outside of a thin, spherical wall and a smooth mass distribution on the inside, that is non-singular at the origin. The solution satisfies the Israel junction conditions at the location of thewall.The mass distribution satisfies the dominant energy condition everywhere, hence can represent physical matter. The central point of our analysis is that our construction of the effective potential forthe location of the wall admits a stable minimum for the position of the location of the wall. Such nega- tive mass bubbles could be important in understanding the formation and existence of voids in the universe.
Page 60 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
W2-4 Fields and Strings II (DTP) | Champs et cordes II (DPT) / 2512
New Gravitational Probes of Dark Matter
Author: Evan McDonough1
1 Brown University
Corresponding Author: [email protected]
Despite decades of searching, the strongest evidence for dark matter remains gravitational. It is thus worthwhile to consider the extent to which gravitational probes can discriminate between models of cold dark matter. With this in mind, in this talk I will discuss the early universe origins andlate universe observables of “superfluid” dark matter. Despite having only gravitational couplings tothe standard model, this scenario provides a suite of complimentary observable signatures. A concrete model realization is SU(2) gauge theory with two massless quarks: At finite particle number density and low temperature, the dark quarks condense and form a superfluid, the collective excitations of which behave as cold dark matter. The associated early universe production of gravitational waves can be probed by the CMB, while halo substructure in the form of vortices and disk-like bound states leaves a characteristic imprint on strong gravitational lensing. Talk based on arXiv:1801.07255 and arXiv:1901.03694.
W1-2 Teaching for Physics Skills Development (DPE) | Développement d’aptitudes pour l’enseignement de la physique (DEP) / 2513
Conceptual Understanding Through Visual Reasoning: An Exam- ple from Quantum Mechanics
Author: Gina Passante1 Co-author: Antje Kohnle 2
1 California State University Fullerton 2 St Andrews University
Corresponding Authors: [email protected], [email protected]
Analyzing, constructing, and translating between graphical, pictorial, and mathematical represen- tations of physics ideas and reasoning flexibly through them is a key characteristic of expertise. Abundant research shows that university physics students at all levels struggle to employ repre- sentations consistently and reflectively, but little instruction in physics is explicitly designed with this purpose in mind. We discuss how development of curricular activities intentionally designed to improve visual learning can improve student conceptual and visual understanding in physics using examples from quantum mechanics. The activities combine interactive computer simulations and University of Washington style tutorials. We will also discuss how learning theories have shaped the structure of the activities. We present results from pre, mid, and posttests to assess transitions in student thinking.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2514
71 - Multi-Bubble Reconstruction in PICO Bubble Chambers
Author: Clayton Coutu1
1 PICO - University of Alberta
Page 61 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
Dark matter signals are expected to be observed in PICO as single bubbles uniformly distributed within the chamber volume, and so far no dark matter candidates have been detected. During the collection of neutron calibration data, what is observed in the PICO chambers are recorded single bubble events that look exactly like the expected dark matter signals, in addition to a dominant pres- ence of multi-bubble events produced by the test source. These events can be used to understand the sources of backgrounds the detectors are sensitive too, and when fully reconstructed they pro- vide information on the chambers efficiency. This talk will show the progress towards the optical reconstruction of multi-bubble events in the PICO 60 bubble chamber.
T3-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-1 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-1 (DPN) / 2515
Production and purification of radium-225 and actinium-225 at TRIUMF’s Isotope Separation On-line (ISOL) facility and subse- quent radiolabeling studies with alpha-emitter actinium-225
Author: Caterina Ramogida1 Co-authors: Andrew K.H. Robertson 2; Peter Kunz 3; Una Jermilova 3; Jens Lassen 3; Ivica Bratanovic 3; Victoria Brown 3; Valery Radchenko 3; Chris Orvig 2; Paul Schaffer 3
1 Simon Fraser University 2 UBC 3 TRIUMF
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
With four alpha particles in its decay chain, actinium-225 (225Ac; t1/2 = 9.9 d) is a promising candidate isotope for Targeted Alpha Therapy (TAT) when coupled with a disease targeting vector. The current limited global supply of 225Ac (67 GBq/year), and lack of appropriate chelating ligands able to complex this isotope has delayed the advance- ment of 225Ac-drugs towards the clinic [1]. Herein, we describe efforts to produce, purify, and evaluate the radiolabeling ability of 225Ac, by leveraging TRIUMF’s ISAC isotope separation on-line (ISOL) facility. 225Ac alongside, parent nuclide radium-225 ( 225Ra; t1/2 = 14.8 d), were produced via spallation of uranium carbide targets with 480 MeV protons on ISOL’s radioactive beam facility. Downstream from the target, a high-resolution mass separator was used to isolate 225Ra and 225Ac ions from other isotopes produced in the spallation process. The 28 keV beam was directed towards an aluminum holder in which the ions were implanted at a depth between 10 and 30 nm. Implan- tation yields of 1.6x108 and 5.7x107 ions/s resulted in isolation of 1.0 – 7.5 and 1.4 – 18.0 MBq of 225Ra and 225Ac, respectively. The implanted activity was etched off the sample stage with dilute acid, and 225Ac was separated in >99% yield from 225Ra using solid phase extraction (DGA resin) [2]. This method has resulted in the isolation of MBq quantities of both 225Ra and 225Ac, where the former can be stored and used as a generator for 225Ac. Subsequently, 225Ac coordination properties with a library of acyclic chelators based on picolinic acids (such as H4(CHX)octapa [3],[4] [N4O4], and H6phospa [5] [N4O6]) along with commercial standard DOTA (N4O4) were evaluated by testing radiolabeling efficiency, and complex stability. In conclusion, wehave successfully established a production method for 225Ac which yields activities ade- quate for pre-clinical screening. Furthermore, several novel actinium-chelators showed promising 225Ac radiolabeling properties and kinetic inertness in vitro compared to DOTA, and will be tested in vivo in future studies.
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M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2516
WITHDRAWN - Low Threshold Analysis with DEAP-3600
Author: Jesse Lock1
1 Carleton University
Corresponding Author: [email protected]
DEAP-3600 (Dark Matter Experiment using Pulse Shape Discrimination) is a direct detection dark matter detector located at SNOLAB in Lively, Ontario. DEAP uses ~3.3 tonnes of liquid argonasits target volume that is housed in a acrylic sphere. In this discussion, I will highlight the technique used to perform a low mass WIMP search with DEAP followed by the expected sensitivity. I will include a brief overview of how the detector works, discuss results that were taken with the nominal DEAP threshold, which will lead into a description of the low mass WIMP search. The differences in how to approach low mass data compared to nominal data will be presented, leading into a showcase of the difference between low threshold data and nominal data. The expected sensitivity ofthelow mass WIMP search will then be discussed.
M1-2 Exploring the energy frontier (PPD) | Explorer la frontière d’énergie (PPD) / 2517
Vector Boson Scale Factor Measurement with the ATLAS Detec- tor
Author: Christina Nelson1
1 McGill University, (CA)
Corresponding Author: [email protected]
Scale factors (SF) are powerful tools for any particle physics analysis. They provide a clean way of estimating particle identification uncertainty. A SF is defined as the ratio of particle identifica- tion efficiency in data to Monte Carlo (MC) simulation. From the SF definition, correlations be- tween systematic uncertainties in data to MC may be cancelled, thereby reducing the systematic uncertainty on a measurement. Because the SF is applied directly to the measurement of a particle production cross-section, understanding the particle identification efficiencies and minimizing the systematic uncertainty are of primary importance. In this study, a W or Z vector boson is identified by its hadronic decay products using tagging techniques on jet substructure observables from the ATLAS detector. The observables implemented are mass and energy correlation fractions, which are functions based on transverse momenta and pair-wise angles between decay particles. After tagging a particle as a W or Z boson, fits with defined functional forms are done on the signal and background distributions in MC. The fits are then applied to data and the tagging efficiencies are extracted. SF measurements and results from the ATLAS detector at CERN using 2015-2018 data will be presented.
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2518
Alpha backgrounds in DEAP-3600
Author: Carl Rethmeier1
1 Carleton University
Corresponding Author: [email protected]
Page 63 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
DEAP-3600 is a liquid argon (LAr) based spin-independent direct dark matter search experiment. It is designed to detect nuclear recoils induced by the elastic scattering of weakly interacting massive particles (WIMPs) on argon nuclei. DEAP-3600 recently reported its second physics result that in- cluded the best reported upper limit on the WIMP-nucleon spin-independent cross section on a LAr target of 3.9×10^−45 cm^2 for a 100 GeV/c^2 WIMP mass at 90% C. L. An essential component of this result involved measuring the rates of alpha-decays within the detector and determining their im- pact on the expected background rate in the WIMP search region. Alpha-decays from the uranium and thorium series were measured in the liquid argon and on the surfaces of the inner-detector. The techniques used to measure and characterize these rates in-situ are presented.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2519
50 - A First Realization of a Quantum Pressure Standard
Authors: Pinrui Shen1; James Booth2; Kirk Madison3; Roman Krems4
1 Department of Physics and Astronomy, University of British Columbia 2 Department of Physics, British Columbia Institute of Technology 3 Department of Physics and Astronomy, University of British Columbia 4 Department of Chemistry, University of British Columbia
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Since the first demonstration of the vacuum by Torricelli (circa 1643), vacuum measurement and technology have been applied to scientific research and industrial technologies including the pro- cessing of semiconductors and the study of the upper atmosphere. However, until now, there has never been a primary pressure standard for the high-vacuum and ultra-high vacuum (UHV), P<10−9 Torr, and lower. Our study of cold atom - hot background particle collisions has solved this problem. In this section, I will present the first quantum pressure standard, which is based on our discovery of a new class of universality (describing the loss rate of atoms from shallow traps of depth). A direct application of this quantum pressure standard is to calibrate and characterize ion gauge performance with different gas species (He, Ar, Xe, N2, H2, and CO2). Further, a MOT can be used asatrans- fer standard, enabling the quantum pressure standard to be connected to other pressure regimes. Finally, some future directions for this quantum pressure standard will be displayed.
M1-8 Neutrinoless Double Beta Decay and Strangeness (DNP) | Double désintégration bêta sans neutrino et étrangeté (DPN) / 2520 nEXO’s Outer Detector: Status and Prospects
Authors: Soud Al Kharusi1; Thomas Brunner2; nEXO CollaborationNone
1 Graduate Student 2 McGill University, TRIUMF
Corresponding Authors: [email protected], [email protected]
The nEXO experiment is a proposed neutrino-less double beta decay (0νββ) search in the isotope Xe-136. Anticipated to be located at SNOLAB, nEXO aims to observe the Majorana nature of neutri- nos with a sensitivity that will probe the entire inverted mass hierarchy parameter space. nEXO’s stringent low-background requirements necessitate a water shield in order to reduce contributions from external radiation. Photomultiplier tubes inside the water will also measure Cherenkov light of passing muons; this active shield is referred to as the Outer Detector. We present the status of Monte Carlo simulations, the instrumentation plan, and muon veto capabilities of the Outer Detector. We
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also discuss the Outer Detector’s potential as a supernova neutrino observatory with a focus on the inverse beta decay interaction channel on hydrogen in the water.
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2521
Measurement of the single electron response of Spherical Propor- tional Counters for the NEWS-G light dark matter search experi- ment
Author: Daniel Durnford1
1 University of Alberta
Corresponding Author: [email protected]
The NEWS-G collaboration employs Spherical Proportional Counters (SPCs) to search for low-mass dark matter. Their excellent sensitivity to the minute energy depositions expected from light dark matter scattering make SPCs fundamentally well-suited for this task, but demands exquisite under- standing of the detector response at the level of single electron/ion pair events. A novel UV laser calibration system has been developed to address this need, allowing for precision measurements of the single electron response of SPCs, which are presented here. Additionally, this calibration system is shown to be ideal for several other key tasks, including measuring the trigger efficiency of SPCs, and monitoring detector stability in real time. The UV laser was also used together with a low energy Ar-37 source to measure the mean ionization energy in a Ne + 2% CH4 gas mixture, demonstrating its future applicability for measuring fundamental gas properties. Bolstered by these results, the UV-laser calibration system will play a crucial role in the next phase of the NEWS-G experiment at SNOLAB.
T2-8 Magnetic resonance imaging (DPMB) | Imagerie par résonance magnétique (DPMB) / 2522
Quantitative Magnetic Resonance Imaging
Author: Dan Xiao1
1 University of Windsor
Corresponding Author: [email protected]
Magnetic resonance imaging (MRI) is well known as a flexible and powerful non-invasive diagnostic imaging technique available to clinical medicine. MRI as a largely qualitative tool is well established, principally used to visualize the internal structure of biological systems through mapping the spa- tial position of hydrogen. The magnetic resonance signal lifetimes (relaxation times) and molecular diffusion usually manifest qualitatively in the MR image contrast. Quantitative analysis ofthese parameters will reveal molecular scale information, since magnetic resonance is sensitive to a range of physical/chemical characteristics including molecular structure, molecular motion, size and inter- actions, through the measurements of relaxation times and molecular diffusion. The potential for quantitative MR has been recognized. However, significant methodological developments are still required for this potential to be fully realized. I will present some recent progress and potential solutions to this challenging problem.
R2-3 Quantum Optics and Ion traps (DAMOPC) | Optique quantique et pièges d’ions (DPAMPC) / 2523
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Topological Structures and Dynamics of Spatially Structured Op- tical Beams
Author: Ebrahim Karimi1
1 University of Ottawa
Corresponding Author: [email protected]
Electromagnetic waves, solutions to Maxwell’s equations, are “transverse” in vacuum. Namely, the waves’ oscillatory electric and magnetic fields are confined within a plane transverse to the waves’ propagation direction. Thus, the polarisation of these fields canbe described by an arbitrary vectorial superposition of two vectors lying in the transverse plane. Though spatially uniform polarised beams are widely used in optics, spatially structured polarised beams have received much attention in the last decades. Such beams may possess well-defined polarisation topological structures in the transverse plane, which is isolated and preserved upon free-space propagation. Under tight-focusing conditions, the polarisation of these beams can exhibit three-dimensional structures, and may result in beams possessing longitudinal electric or magnetic field. Such structures can exhibit features such as transverse spin angular momentum; and non-trivial topologies such as Möbius or Ribbon strips. In my talk, I will present the recent progress, challenges, and developments in structuring the polarisation of optical beams. The stability and the dynamics of two- and three-dimensional polarisation topologies, e.g. Möbius and Ribbon strips, as well as knots, will also be the subject of my presentation.
W1-4 Advances in Nuclear and Particle Theory (DTP/PPD/DNP) | Progrès en théorie nucléaire et théorie des particules (DPT/PPD/DPN) / 2524
Cosmological Bounds on Non-Abelian Dark Forces
Authors: Lindsay Forestell1; David Morrissey2; Kris Sigurdson3
1 UBC, TRIUMF 2 TRIUMF 3 UBC
Corresponding Authors: [email protected], [email protected]
Non-Abelian dark gauge forces that do not couple directly to ordinary matter may be realized in nature. If the dark sector is reheated in the early universe, it will be realized as a set of dark gluons at high temperatures and as a collection of dark glueballs at lower temperatures, with a cosmological phase transition from one form to the other. These glueballs can be, if left alone, the cosmological dark matter. We explore the parameter space needed to satisfy present day densities. However, despite being dark, these new glueball states can also connect indirectly to the Standard Model through various operators. These interactions will transfer energy between the dark and visible sectors, and they allow some or all of the dark glueballs to decay. We investigate the cosmo- logical evolution and decays of dark glueballs in the presence of connector operators to the Standard Model. Dark glueball decays can modify cosmological and astrophysical observables, and we use these con- siderations to put very strong limits on the existence of pure non-Abelian dark forces. On the other hand, if one or more of the dark glueballs are stable, we find that they can potentially make up the dark matter of the universe.
Page 66 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2525
84 - On the Neutrino Floor for the Next Generation of Liquid No- ble Dark Matter Experiments
Author: Andréa Gaspert1
Co-authors: David Morrissey 1; Pietro Giampa
1 TRIUMF
Corresponding Authors: [email protected], [email protected], [email protected]
As dark matter detectors grow larger and more efficient, neutrinos from the sun and other cosmolog- ical sources become a significant background. If predictions hold true, the next generation of detec- tors is set to reach the neutrino floor. The neutrino floor typically shown was computed specifically for an ideal Xenon scintillator detector, using a Maxwellian speed distribution for the dark matter in the Milky Way. Although this represents a good estimation, it is of insufficient precision when good predictions for specific experiments are needed. In this work, the objective is two-fold. We first study the impact of detector properties on the neutrino floor. We then show how uncertainties on neutrino fluxes and on the distribution of dark matter in our vicinity impacts predictions. We first computed the neutrino floor for currently proposed future Xenon TPC and Argon single- phase dark matter detectors. We include the impact of neutrino-electron scattering and showthat Argon detectors have a significantly lower neutrino floor for higher dark matter particle masses.We also computed the impact of a potential anisotropy in the dark matter distribution and show that it has a negligible impact on the interpretation of future experimental results. We finally discuss how a more precise knowledge of neutrino fluxes on earth could potentially push the neutrino floor limit lower.
M1-3 Magnetism and Heavy Fermions I (DCMMP) I Magnétisme et fermions lourds I (DPMCM) / 2526
Frustrated magnetism on 2D triangular, metallic antiferromag- nets
Author: Eundeok MunNone
Co-authors: Jeonghun Lee 1; Anja Rabus 1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected]
For Ce- and Yb-based metallic systems, the competition between Kondo and RKKY interactions re- sults in a great variety of ground states. When these rare-earth ions are located on the geometrically frustrated lattices, the magnetic order may be tuned by the introduction of magnetic frustration. Although the lattices are geometrically frustrated for the short range, nearest neighbor spin-spin interaction, often the conduction electron degree of freedom in metals takes over the longer-ranged interactions. Due to this reason, the effect of geometrical frustration in metals is not obvious. In this talk, I will present the frustration effect on two-dimensional, triangular lattice, metallic antifer- romagnets.
M2-9 Magnetism and heavy fermions II (DCMMP) | Magnétisme et fermions lourds II DPMCM) / 2527
Page 67 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Anomalous transport property in Re3Ge7
Author: Anja Rabus1
Co-author: Eundeok Mun
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
The rhenium (Re)-based compounds are difficult to synthesize owing to the element’s highmelt- ing temperature and low solubility into solid solution. In this talk, we will present an anomalous transport property observed in single crystal Re3Ge7. In zero field, the temperature dependence of electrical resistivity sharply increases below a phase transition temperature Tc = 58.5 K, showing a metal-to-insulator-like transition. Analysis of the Hall coefficient measurements indicates that the carrier density is 0.04 per formula unit at 300 K and drops by two orders of magnitude below Tc. When magnetic field is applied, the temperature dependence of resistivity develops amaximum around 30 K, deviating from an ordinary metallic behaviour. At low temperatures, the Shubnikov- de Hass quantum oscillations are detected on top of the linear field dependence of magnetoresis- tance.
T2-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria AM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria AM-2 (DPN) / 2528
Life with a Scientific Cyclone: Personal reflections on my collab- orations with John D’Auria
Author: Thomas Ruth1
1 TRIUMF
Corresponding Author: [email protected]
From shortly after my arrival at TRIUMF I was swept up in the enthusiastic approach thatJohn pursued. Starting with basic studies in pion exchange to separated isotopes at TISOL to cyclotron produced tracers for DRAGON and back again to off-line separated isotopes for medicine. I will describe the breadth of the explorations John pursued and their impact on science in general and the arch of my career.
R2-7 Nuclear Structure IV (DNP) | Structure nucléaire IV (DPN) / 2529
Single-particle structure of 93,94,95Sr nuclei
Authors: Soumendu Sekhar Bhattacharjee1; S. Cruz2; P. C. Bender2; R. Krucken2; K. Wimmer3; F. Ames2; C. Andreoiu4; C. S. Bancroft5; R. Braid6; T. Bruhn2; W. N. Catford7; A. Cheeseman2; A. Chester2; D. S. Cross4; C. Aa. Diget8; T. Drake9; A. B. Garnsworthy2; G. Hackman2; R. Kanungo10; A. Knapton7; W. Korten11; K. Kuhn6; J. Lassen2; R. Laxdal2; M. Marchetto2; A. Matta12; D. Miller2; M. Moukaddam2; N. A. Orr13; N. Sachmpazidi5; A. Sanetullaev2; C. E. Svensson14; N. Terpstra5; C. Unsworth4; P. J. Voss4
1 F. Ames 2 TRIUMF, Vancouver, BC V6T 2A3, Canada 3 Department of Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 4 Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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5 Department of Physics, Central Michigan University, Mt Pleasant, MI 48859, USA 6 Department of Physics, Colorado School of Mines, Golden, CO 80401, USA 7 Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom 8 Department of Physics, University of York, York, YO10 5DD, United Kingdom 9 Department of Physics, University of Toronto, Toronto, ON M5S 1A7, Canada 10 Department of Astronomy and Physics, Saint Mary’s University, Halifax, NS B3H 3C2, Canada 11 IRFU, CEA, Universit ́e Paris-Saclay, F-91191 Gif-sur-Yvette, France 12 LPC, ENSICAEN, CNRS/IN2P3, UNICAEN, Normandie Universit\’{e}, 14050 Caen cedex, France 13 LPC, ENSICAEN, CNRS/IN2P3, UNICAEN, Normandie Universit ́e, 14050 Caen cedex, France 14 Department of Physics, University of Guelph, Guelph, ON, N1G 2W1, Canada
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], al- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] tokyo.ac.jp, [email protected], [email protected], [email protected], [email protected], [email protected]
The level structure of neutron rich 93,94,95Sr were studied via the \dtsr{94,95,96}, one neutron pickup reactions at TRIUMF. Excited states were populated when 94,95,96Sr beams of 5.5 AMeV bombarded a 2 0.44 (4) mg/cm CD2 target. The de-exciting γ-rays and outgoing charged particles were detected by using the TIGRESS and SHARC arrays, respectively. The level scheme was contructed by using bothEx vs Eγ and Eγ vs Eγ matrices. Three excited states were observed in 93Sr and 95Sr, respectively. A total of ten excited states were observed in 94Sr of which four states were newly identified in the present experiment. Angular distribution measure- ments suggest spin and parity assignments for the 1880 (0+), 2294 (0+) and 2415 (3+) keV levels and constrain the other five levels 2615, 2705, 2921, 3077 and 3175 keVin 94Sr. In this work no γ-ray transitions were observed from the 1880 and 2294 keV levels directly to the ground state. This is consistent with spin and parity assignments of the 1880 and 2294 keV levels as 0+. The spectro- scopic factors were calculated by fitting DWBA calculations to experimental angular distribution data and taking into consideration γ-decay branching ratios. Shell model calculations were carried out to understand the present experimental observations by using updated interaction and appropri- ate truncation schemes. The calculation was performed by using an updated NuShellX codeand glek interaction. The single- particle energies of the interaction were adjusted in such a way that the calculated and experimen- tally observed energy levels were in good agreement in the N ∼ 56 and Z ∼ 38 region. In the present calculations the valence [1d5/2], [2s1/2], [1d3/2] and [0g7/2] orbitals were included for neu- trons outside the N = 50 inert core. The proton degrees of freedom were varied systematically so that the effect of the proton valence space on the calculated levels could be studied. The calculated energy levels and spectroscopic fac- tors that were predicted are in reasonable agreement with the experimental findings. This suggests that the low-energy states are predominantly neutron configurations with minor contributions from excitations between the proton [1p3/2] and [1p1/2] orbitals.
M1-3 Magnetism and Heavy Fermions I (DCMMP) I Magnétisme et fermions lourds I (DPMCM) / 2530
Physical properties of Yb3Ru4Ge13 and Lu3Ru4Ge13
Authors: Jeonghun Lee1; Eundeok MunNone
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
Page 69 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Cubic compounds with Yb3Rh4Sn13-type structure have drawn attention because of their rich ground states such as heavy fermion behavior, intermediate valence behavior, charge density wave, and su- perconductivity. In this talk, we will present the structural, magnetic, and electrical properties of cubic R3Ru4Ge13 (R = Yb and Lu) compounds. Single crystals of R3Ru4Ge13 were characterized by magnetization, specific heat and electrical resistivity measurements. The resistivity measurement of Yb3Ru4Ge13 compound exhibits a metallic behavior, whereas Lu3Ru4Sn13 compound shows a semiconductor-like behavior with a superconducting transition at ~2.2 K. Low-temperature specific heat measurement indicates Yb3Ru4Ge13 is a heavy fermion.
DTP Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPT et finales du concours d’affiches étudiantes (4) / 2531
24 - Einstein-Maxwell-dilaton solution in Bianchi type IX
Author: Bardia Hosseinzadeh FahimNone Corresponding Author: [email protected]
We construct new classes of cosmological solution to the five-dimensional Einstein-Maxwell-dilaton theory that are non-stationary and almost conformally regular everywhere. The base geometry for the solutions is four-dimensional type XI Bianchi geometry. In the theory, the dilaton field couples to both electromagnetic field and the cosmological constant term with two different coupling constants. We consider all possible solutions with different values of the coupling constants as well as the cosmological constant, as a positive, negative or zero -valued constant. In the ansatzes for the metric, dilaton and electromagnetic fields, we consider dependence on one time and two spatial directions. We discuss the physical properties of the five-dimensional space- time. We also consider the special case of the Bianchi type IX geometry in which the geometry reduces to that of Eguchi-Hanson space. Presentation type: poster
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2532
Cardiorespiratory Fitness Evaluation using Submaximal protocol with Muscle Oxygenation
Authors: Zhaopeng Fan1; Gong Zhang2; Huixin Zhang3; Melanie Martin2; Liping Huang4
1 Winnipeg Regional Health Authority 2 University of Winnipeg 3 University of Manitoba 4 Chinese PLA General Hospital
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Low levels of cardiorespiratory fitness (CRF) are associated with high risk of cardiovascular disease (CVD) and all-cause mortality. Maximal oxygen consumption (VO2max) has been considered as a gold standard for determining CRF, which can be precisely measured by using the cardiopulmonary exercise testing (CPX) device with a maximal exercise protocol. However, this traditional method- ology can be unavailable due to its high cost and risk. VO2max itself is not complete solution for CRF evaluation as it shows the level of CRF only. What limits the level of CRF and how to make improvement efficiently are not answered by VO2max. Recently, an alternative approach hasbeen raised by researchers to evaluate VO2max by submaximal test based on the heart rate (HR). Com- pared with the maximal exercise based method, this submaximal test approach is more applicable
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and much safer, but at an expense of the VO2max estimation accuracy. Motivated by this, our group has proposed a novel method, which adds a new personalized performance related metric-muscle oxygen saturation (SmO2) that can be measured by a portage Near infrared spectroscopy (NIRS) de- vice, to further improve the submaximal test accuracy and show the physical limitations that caused low levels of CRF. Furthermore, we also propose an adjustment algorithm to evaluate CRF with ma- chine learning approach. Our test results show that the proposed adjustment algorithm improves the VO2max estimation in submaximal test and indicates the physical limitation for each subject at their own level of CRF, which thus demonstrates the feasibility of using SmO2 for CRF evaluation. To our best knowledge, our group is the first to propose this idea, which will be of great significance to clinical applications.
W1-7 Detectors for Particle Physics (DAPI/PPD) | Détecteurs pour la physique des particules (DPAI/PPD) / 2533
Analog Electronics and SiPM Characterization for LOLX
Author: Austin de St. Croix1
1 TRIUMF/UBC
Corresponding Author: [email protected]
The Light Only Liquid Xenon (LOLX) experiment aims to investigate both scintillation andCherenkov light emission in liquid xenon using 24 Hamamatsu VUV4 Silicon Photomultipliers (SiPMs). Analog electronics are used to perform summing of 4 SiPM channels prior to signal amplification, with the goal of retaining single photon counting and sub nanosecond timing resolution. Additionally, LOLX aims to characterize cross-talk between opposing SiPMs as this process can falsely contribute to the measured light signal. LOLX will provide SiPM R&D and testing of photon transport codes related to the nEXO neutrinoless double beta decay experiment. This talk will discuss the optimization of SiPM performance with the analog electronics andcharac- terization of external cross-talk in air.
M1-5 Nuclear Astrophysics (DNP) | Astrophysique nucléaire (DPN) / 2534
Decay Spectroscopy of Neutron-Rich Cd Around the N = 82 Shell Closure with GRIFFIN
Authors: Yukiya Saito1; Nikita Bernier2 Co-authors: Iris Dillmann ; Reiner Kruecken 3; M. Bowry 4; A. N. Murphy 3; Corina Andreoiu 5; Gordon Ball 3; H. Bidaman 6; Paula Boubel 7; Christina Burbadge ; Roger Caballero-Folch 3; Michelle Dunlop 7; Ryan Dunlop 7; Lee Evitts 3; Fatima Garcia 5; A. B. Garnsworthy 4; P. E. Garrett 8; Greg Hackman 3; S. Hallam 3; Jack Henderson 3; Sergey Ilyushkin ; Andrea Jungclaus 9; D. Kisliuk 7; Jens Lassen 3; R. Li 3; E MacConnachie 3; A. D. MacLean 8; E. McGee 7; Mohamad Moukaddam 3; B. Olaizola 4; E Padilla-Rodal 10; Jason Park 11; O. Paetkau 3; Costel Petrache 12; Jennifer Pore ; Allison Radich 13; P. Ruotsalainen 3; J. Smallcombe 4; J. K. Smith 14; C. E. Svensson 8; S. L. Tabor 15; Andrea Teigelhoefer 3; Joseph Turko 7; T. Zidar 6
1 The University of British Columbia / TRIUMF 2 UBC/TRIUMF 3 TRIUMF 4 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 5 Simon Fraser University 6 Department of Physics, University of Guelph, Guelph, Ontario 7 University of Guelph
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8 Department of Physics, University of Guelph, Guelph, Ontario 9 CSIC 10 ICN-UNAM 11 University of British Columbia/TRIUMF 12 University Paris Sud 13 university of Guelph 14 Reed College 15 Florida State University
Corresponding Authors: [email protected], [email protected], [email protected], hack- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], rcaballero- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Nuclei around doubly magic 132Sn are of particular interest in nuclear structure as well as nuclear astrophysics. The evolving shell structure near the shell closure is ideal for testing the current nuclear models far from stability. Additionally, the extra binding energy observed around 132Sn has direct implications in astrophysical models, leading to the second r-process abundance peak at A ∼ 130. While the decays of neutron-rich Cd isotopes around the N = 82 shell closure have been previously investigated, the information on some of the daughter In isotopes such as 128In is still limited. For 129In, the two reported level schemes have large discrepancies [1, 2]. It is also worthwhile to verify the recent results on the decay of 130-131Cd [3, 4, 5]. Detailed β-γ-spectroscopy of 128-131Cd was performed at the ISAC facility of TRIUMF, Canada. The data was collected with the GRIFFIN spectrometer, along with the β-particle detector SCEPTAR. The half-lives of 128-130Cd have been measured and reported [6]. In 128In, 32 new transitions and 11 new states have been observed in addition to the four previously observed excited states. The 128Cd half-life has also been re-measured with a higher precision via the time distribution of the strongest gamma rays observed in the decay. For 129In, 29 new transitions have been observed and 5 new excited states have been established. The logft values obtained suggest the dominant β- decay mode is the ν0g7/2 → π0g9/2 Gamow-Teller transition, which is consistent with the known characteristics of the β-decays in the Z < 50, N ≤ 82 region. The new results for the decay of 128-131Cd will be presented and compared with previous studies as well as with shell model and IM-SRG calculations. [1] O. Arndt et al., Acta Phys. Pol. B 40, 437 (2009). [2] J. Taprogge et al., Phys. Rev. C 91, 054324 (2015). [3] J. Taprogge et al., Phys. Rev. Lett. 112, 132501 (2014). [4] A. Jungclaus et al., Phys. Rev. C 94, 024303 (2016). [5] J. Taprogge et al., Eur. Phys. J. A 52, 347 (2016). [6] R. Dunlop et al., Phys. Rev. C 93, 062801(R) (2016).
W2-8 Nuclear Astrophysics II (DNP) | Astrophysique nucléaire II (DPN) / 2535
Mass Measurements of Neutron-Rich Indium Isotopes for Enhanced r-Process Studies
Author: C. Izzo1
Co-authors: T. Brunner 2; K. Dietrich 1; J. Dilling 3; I. Dillmann ; E. Dunling 1; D. Fusco 4; G. Gwinner 5; A. Jacobs 1; B. Kootte ; G. Kripkó-Koncz 6; Y. Lan 1; D. Lascar 7; K.G. Leach 8; E. Leistenschneider 1; M. Lykiardopoulou 1; I. Mukul 1; S.F. Paul 1; M.P. Reiter 9; R. Thompson 10; J.L. Tracy, Jr. 1; M. Wieser 11; A.A. Kwiatkowski 1
1 TRIUMF
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2 McGill University 3 triumf/UBC 4 TRIUMF/University of Waterloo 5 University of Manitoba 6 Justus-Liebig University Giessen 7 Northwestern University 8 Colorado School of Mines 9 TITAN 10 University of Calgary, Canada 11 University of Calgary
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], ish- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], gwin- [email protected]
The astrophysical r-process is responsible for the production of approximately half of the observed abundance of atomic nuclei heavier than iron. A complete understanding of the r-process requires reliable atomic mass data for neutron-rich isotopes far from stability, where experimental access is often limited by low production rates, high rates of contamination, and short half-lives. Asare- sult, r-process simulations rely heavily on phenomenological models which predict atomic masses using extrapolations from known masses. Such predictions come with a relatively high degree of uncertainty, limiting the ability of r-process simulations to constrain the astrophysical conditions required to obtain the observed elemental abundances. In particular, recent sensitivity studies have demonstrated that reducing current uncertainties in the masses of neutron-rich indium isotopes would play an important role in constraining astrophysical models at the second r-process abun- dance peak around A=130. TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) is among the world leaders in achiev- ing precise and accurate mass measurements of exotic isotopes. The recent addition of a Multiple- Reflection Time-of-Flight (MR-TOF) mass spectrometer has further expanded the measurement capa- bilities at TITAN, combining high resolution with fast measurement times to achieve high-precision mass measurements of rare isotopes previously inaccessible due to high contamination rates and short half-lives. Most recently, the TITAN MR-TOF was used to measure the masses of neutron-rich indium isotopes from A=125-134. This is the first time the masses of 133,134In have ever been measured. Additionally, several isomeric state masses with half-lives as short as 5 ms were resolved from the ground state masses in these measurements. The results of these measure- ments will be presented along with a discussion of their impact for understanding the astrophysical r-process.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2536
Atomic force microscopy reveals how structural variations im- pact the flexibility of collagen
Authors: Alaa Al-Shaer1; Nancy Forde2; Aaron Lyons2 Co-authors: Billy Hudson 3; Sergey Boudko 3
1 Simon Fraser Univeristy 2 Simon Fraser University 3 Vanderbilt University
Corresponding Authors: [email protected], [email protected]
Collagen, the most abundant protein in mammalian organisms, is responsible for the cohesion of tissues and organs. It is a major structural component of our extracellular matrix, contributing to
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the mechanical stability, organization, and shape of a wide variety of tissues. Many collagen types have been reported in humans, all of which are triple-helical proteins that assemble into distinct higher-order organizational structures. To date, there has been greater focus on characterizing the more abundant fibrillar collagen types, leaving the mechanical properties of network-forming col- lagen type IV comparatively understudied. A key feature that differentiates fibrillar collagens from collagen IV lies in the characteristic triple-helical defining (Gly-X-Y)n sequence of the collagenous domain, where collagen IV has intrinsic discontinuities in its sequence. The role and structure of these interrupted Gly-X-Y regions remains unknown; however, it has been suggested that they play a role in the flexibility of the collagen molecule. To address this question, we used atomic force microscopy (AFM) to sample the two-dimensional conformations adopted by collagen on mica and performed statistical analysis to calculate its persistence length – a mechanical property that is used to quantify the flexibility of a polymer. By assuming homogeneous flexibility across the lengthof the molecule, we found the persistence length of collagen IV to be less than half of that of the con- tinuously triple-helical fibrillar collagens. To investigate local sequence variations, we developed an algorithm that determines position-dependent persistence length profiles. We found significant vari- ations in persistence length along the contour of the collagen IV molecule, where regions of higher flexibility correlated strongly with interrupted Gly-X-Y regions in its amino acid sequence.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2537
76 - Measurement of SuperKEKB Electron Beam Polarization through Tau Forward-Backward Polarization Asymmetry
Author: Caleb Miller1
Co-author: Michael Roney 1
1 University of Victoria
Corresponding Authors: [email protected], [email protected]
Presently the Belle II experiment at SuperKEKB is colliding e+e− beams at the Υ(4S) resonance. These beams currently have no polarization, but if SuperKEKB and Belle II were to be upgraded to make use of polarized electron beams a significant number of electroweak precision measurements could be made. However, in addition to the technical difficulties in creating a polarized beam for collisions, it is difficult to know the exact amount of polarization that remains at the momentof collision. This uncertainty can become a leading systematic uncertainty limiting the precision of physics measurements. The beam polarization can be measured with sub-percent precision by making use of the relation- ship between beam polarization and the forward-backward asymmetry in the polarization of tau leptons produced in the e+e− collisions. By measuring the asymmetry, a precise value for the beam polarization at the e+e- interaction point can be determined. In this talk I will show results from applying this analysis method to the unpolarized beams deliv- ered by SLAC to the BaBar experiment. I will also discuss the feasibility of applying the analysis technique as a measurement tool of beam polarization for a potential upgrade of polarized electron beams to SuperKEKB/Belle II.
M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2539
Li-Hong as a supporter of Asian Arts: A dance dedication
Author: Irene Vavasour1
1 University of British Columbia
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Corresponding Author: [email protected]
Devi. She is a warrior, a beautiful wife, a mother, a scholar. These attributes can equally describe Li- Hong. Apart from her strength as a physicist, Li-Hong was a huge patron of the Asian Arts in Saint John. This dance presentation in Bharatanatyam, a classical dance style of South India, describes the goddess Devi. As a dedication to Li-Hong, I will draw parallels between her and the goddess.
M2-1 Interaction Between Matter and Light (DAMOPC) | Interaction de la matière et de la lumière (DPAMPC) / 2540
Do the temperature dependencies of spectral line parameters change when we approach cryogenic temperatures?
Authors: Adriana Predoi-Cross1; Nazrul Islam1; Mary Ann Smith2; Malathy Devi3; Sergey Ivanov4; Oleg Buzykin5; Franck Thibault6
1 University of Lethbridge 2 Science Directorate, NASA Langley Research Center 3 Department of Physics, The College of William and Mary 4 Institute on Laser and Information Technologies, Russian Academy of Sciences 5 Central Aerohydrodynamic Institute (TsAGI) 6 Universite de Rennes
Corresponding Author: [email protected]
We have recently studied a set of 40 spectra of carbon monoxide in pure state and mixed with air, recorded at temperatures between 79 to 296 K. Our aim was to investigate if the temperature depen- dencies of line parameters, such as half widths and pressure induced shifts, stay the same at very low temperatures, close to 79 K. The spectra were all recorded over two decades using the 1-m Fourier Transform spectrometer located at Kitt Peak, AZ, USA and two temperature controlled gas cells. The spectra were calibrated using the line positions for residual carbon dioxide and water vapour and referencing them to the HITRAN database. The constrained analysis technique was used together with the software Labfit [2]. Three lineshape models were employed: Voigt, speed-dependent Voigt and Rautian. In the absence of experimental narrowing parameters, we have calculated them using computed diffusion constants [3]. The theoretical half-width coefficients for CO-N2 have been determined at several temperatures em- ploying a potential energy surface of Tipping-Herman type, vibrationally independent potentials and by taking into account the electrostatic interactions. We will discuss what laws were fund to best represent the temperature dependencies over a wide range of temperatures, approaching cryo- genic temperatures. We thank D. Chris Benner for the Labfit software. The work of V.M. Devi was funded byNASA grants and contracts, and the research by M. A. H. Smith was performed as part of her employment at NASA Langley Research Center. No official endorsements are intended or implied. N. Islam andA. Predoi-Cross have been funded by NSERC. S. Ivanov and O. Byzykin received financial support from the Ministry of Science and Higher Education within the State assignment FSRC «Crystallography and Photonics» RAS and Russian Science Foundation (Project No.18-55-16006). References: 1. I.E. Gordon, L.S. Rothman, C. Hill, R.V. Kochanov, Y. Tan, P.F. Bernath, et al. J. Quant. Spectrosc. Radiat. Transfer 203, 3–69 (2017). 2. D.C. Benner, C.P. Rinsland, V.M. Devi, M.A.H. Smith, D. Atkins, J. Quant. Spectrosc. Radiat. Transfer 53(6), 705-721 (1995). 3. J.O. Hirschfelder, C.F. Curtiss, R.B. Bird, Molecular theory of gases and liquids. New York: Wiley and Sons, 1952.
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M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2541
Li-Hong Xu as a mentor and scholar
Author: Adriana Predoi-Cross1
1 University of Lethbridge
Corresponding Author: [email protected]
Physics continues to be a male-dominated field. Sometimes it is difficult for women in physics with diverse cultural backgrounds, to find mentors that they can trust and that will guide them through difficult times in their career. This talk will discuss how younger women in physics havebenefited from the one-on-one mentoring offered by Li-Hong Xu during her distinguished academic career. As a role model, Li-Hong Xu was leading by example, sharing her own stories and experiences, dis- cussing how to balance work and personal life, guiding and providing support for the professional development of other women physicists. The mentees were encouraged to strive to achieve their full potential. Career expectations, career stages and paths to achieve them were often discussed. Par- ticipating together with Li-Hong at social activities and events contributed to building communities in the department or at national level through CEWIP.
T3-9 Cosmology (DTP) | Cosmologie (DPT) / 2542
Searching for new physics with next generation CMB experiments
Author: Levon Pogosian1
1 SFU
Corresponding Author: [email protected]
I will discuss the current status and future prospects of searching for cosmic microwave background signatures of cosmic birefringence, primordial magnetic fields and cosmic strings, and implications for fundamental physics.
M2-6 Accomplished women inspiring future women in physics: Li-Hong Xu (CEWIP) I Femme accomplie qui inspire de futures physiciennes: Li-Hong Xu (CEFEP) / 2543
UBC High School Physics Olympics: Past, Present, and Future
Authors: Janis McKenna1; Marina Milner-Bolotin2
1 University of British Columbia 2 The University of British Columbia
Corresponding Authors: [email protected], [email protected]
University of British Columbia (UBC) Physics Olympics is a high school physics competition held on UBC Vancouver campus ( https://physoly.phas.ubc.ca/ ). This annual outreach event attracts more than 500 high school students, competing in teams, accompanied by more than 70 teachers and coaches from across the province. This competition, organized by the Department of Physics and Astronomy and the Department of Curriculum and Pedagogy at UBC, is one of the largest and
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oldest high school physics competitions of its kind in North America. More than 70 UBC volunteers – physics and education faculty members, graduate and undergraduate students, and staff collaborate before and during the event to make it a reality. The competition consists of six hands-on events (heats), of which two require devices which are designed and built by the students in the weeks before the competition. In recent years, it has also included professional development workshops and networking opportunities for physics teachers and coaches who accompany the teams to the competition. The event engages students in physics in a friendly and collaborative environment where all students are welcome. Many of the teams come from the far reaches of the province of British Columbia, and the event has become an annual field trip for the students - one of the perks of getting involved in secondary school physics. Many of the high schools have been attending the event for decades, thus helping support a physics teaching community in the province.
T4-9 Quantum Theory (DTP) | Théorie quantique (DPT) / 2544
First Order Relativistic Correction to Landau Levels in the Pres- ence of a Parallel Linear Electric Field
Author: Yann Audin1
1 Bishop’s University
Corresponding Author: [email protected]
We consider a three-dimensional system where a relativistic electron moves under a constant mag- netic field and a linear electric field parallel to the magnetic field above the z=0 plane andantiparallel below the plane. We use the Dirac equation and perturbation theory to determine analytically the first order relativistic correction to the Landau levels under the above static fields.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2545
WITHDRAWN - 2H NMR investigation of the phase behaviour of phospholipid membranes containing cholesterol and ceramide
Author: Reza Siavashi1
Co-authors: Tejas Phaterpekar 2; Sherry Leung 2; Felix Goni 3; Alicia Alonso 3; Jenifer Thewalt 2
1 Department of physics- Simon Fraser University 2 Simon Fraser University 3 Department of Biochemistry and Molecular Biology, University of the Basque Country
Corresponding Authors: [email protected], [email protected]
Sphingolipids constitute a significant fraction of cellular plasma membrane lipid content. Among sphingolipids, ceramide levels are usually very low. However, in some cell processes like apoptosis, cell membrane ceramide levels increase markedly due to activation of enzymes like sphingomyeli- nase. This increase can alter membrane fluidity. Increased molecular order and solid ordered (So) phase domain formation has been observed in a previous 2H NMR study on membranes consisting of palmitoyl sphingomyelin (PSM) and palmitoyl ceramide (PCer). Cholesterol (Chol), which is also present at high concentrations in mammalian plasma membranes, has a favorable interaction with sphingomyelin (SM). Together they form domains liquid ordered (Lo) phase domains in model mem- branes. There are reports that Chol is able to displace ceramide (Cer) in SM bilayers and abolishthe So phase domains formed by SM:Cer. This ability of Chol appears to be concentration dependent; in membranes with low Chol and high Cer contents, So phase domains hypothesized to be rich in Cer
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coexist with the continuous fluid phase of the membrane. Here, we present studies on the effectof increasing PCer concentration in PSM:Chol bilayers, using 2H NMR. Chol:PCer mol ratios were 3:1, 3:2 and 3:3, at a fixed 7:3 PSM:cholesterol mol ratio. Both PSM and PCer were monitored, insepa- rate samples, for changes in their physical state by introducing a perdeuterated palmitoyl chain in either molecule. Second, we investigate the effect of replacing PSM with DPPC to test the influence on membrane phase behavior of replacing sphingosine with a palmitoylated glycerol backbone. We found that PCer induces highly stable So phase domains in both PSM:Chol, DPPC:Chol bilayers. This effect is most pronounced in bilayers with Chol:PCer 1:1 molar ratios, and below 40 oC. PCerismore effective in ordering PSM:Chol bilayers than analogous bilayers composed of DPPC:Chol.
W2-8 Nuclear Astrophysics II (DNP) | Astrophysique nucléaire II (DPN) / 2546
High-precision mass measurement of n-rich Rb & Sr isotopes at TITAN
Author: Ish Mukul1
Co-authors: Anna Kwiatkowski 1; C. Andreoiu 2; Maxime Brodeur 3; Kilian Dietrich 4; Thomas Brunner 5; Iris Dillmann ; ELEANOR DUNLING 1; Gerald Gwinner 6; D. Fusco 7; A. Jacobs 1; Christopher Izzo 1; Brian Kootte ; Yang Lan 1; Erich Leistenschneider 1; M. Lykiardopoulou 1; S.F. Paul 1; Moritz Pascal Reiter 8; Robert Thompson 9; J.L. Tracy, Jr. 1; Michael Wieser 10; Jens Dilling 11
1 TRIUMF 2 Simon Fraser University 3 University of Notre Dame 4 Heidelberg University, Germany; TRIUMF, Canada 5 McGill University 6 U. Manitoba 7 TRIUMF/University of Waterloo 8 TITAN 9 University of Calgary, Canada 10 University of Calgary 11 triumf/UBC
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
High-precision mass spectroscopy plays a decisive role in addressing several open questions in con- temporary nuclear physics, for example, to explain the observed abundances of atoms heavier than iron. About half of the neutron-rich isotopes up to uranium are synthesized via the rapid-neutron capture process (r-process) where the final nuclear abundance depends sensitively on the nuclear mass. Due to the exotic nature of r-process nuclei, their masses are usually uncertain (or unmea- sured) and must be calculated using nuclear mass models. We have performed mass measurements of nuclei in the A = 100 mass region that lies in the r-process path using ion-trapping techniques to better constrain nuclear mass models. The masses of isotopic chains of 99-103 Rb and 99-105Sr were measured with 103Rb and 104-105Sr be- ing measured for the first time. The mass measurements were performed at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) facility, which is one of a kind for precision mass spectrometry. A Multi-Reflection Time- Of-Flight Mass Separator (MR-TOF-MS) was used as the mass spectrometer of choice. We have used the MR-TOF technique to measure these masses of ions with low intensities (~0.1 pps) and small half-lives (>25 ms). In this conference, we would like to present the results of mass measurements of n-rich Rb and Sr isotopes.
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T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2547
Interplay between native state topology and sequence in two-state protein folding
Authors: Stefan Wallin1; Daniel Trotter2
1 Memorial University of Newfoundland 2 University of Ottwawa
Corresponding Author: [email protected]
One of the outstanding questions in protein folding is why the folding into some native state topolo- gies, e.g. all-α folds, are more sensitive to sequence variations than other, more nonlocal protein folds, such as all-β folds? To explore this question, we design and study three 35-54 amino acid se- quences within a coarse-grained sequence-based model and show that they fold spontaneously into stable 3α, 4β + α and β-barrel folds, respectively. Their thermodynamic behaviors, calculated using Monte Carlo techniques, exhibit features in line with experimental data including rank order of fold- ing cooperativity and temperature-driven Hammond shifts of transition states. Using a novel gen- eralized ensemble algorithm (A. Aina and S. Wallin, Journal of Chemical Physics 147, 095102, 2017) we then systematically study the effect of single- and double-point mutations on each of the three proteins. In total, >2,000 mutants are studied. We find that the proteins respond to sequence varia- tions in a topology-dependent manner. In particular, the folding landscape of the β-barrel protein is the least perturbed of the three proteins, explaining previously observed mutational robustness of non-local folds. Moreover, we observe a link between the size of conformational fluctuations of these proteins and the divergence exhibited by their respective mutants. One consequence of such a link is that proteins with diverse folding pathways might be more sensitive to sequence variations than proteins with restricted folding pathways.
T2-8 Magnetic resonance imaging (DPMB) | Imagerie par résonance magnétique (DPMB) / 2548
Development of 7 Tesla Magnetic Resonance Imaging Guided Robotic System
Authors: Bocheng Xu1; Qingjin Peng1; Gong Zhang2; Huixin Zhang1; Melanie Martin2; Liping Huang3
1 University of Manitoba 2 University of Winnipeg 3 Chinese PLA General Hospital
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Stereotaxy is a neurosurgical technique guided by preoperative imaging. Its procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization. The intervention is basically “blind” for the operator with limited means of intra-operative confirmation that may result in the reduced accuracy and safety. It may take several hours to reach a specific target. The magnetic resonance imaging (MRI)-guided robotic stereotactic neural intervention system offers the potential to reduce surgical duration while improving target accuracy and safety. Current studies show that the use of MRI for guiding robotic surgical devices has a great potential for performing precisely targeted and controlled interventions. However, the currently developed project of robotic system is limited to being compatible with clinical 1.5T-3.0T MRI scanners as well as expensive sales. The proposed project dedicates in developing and deploying MRI-compatible robotic systems, and enables the technologies for intra-operative MRI-guided based interventions. The preliminary work will be involved in the design of robotic mechanisms, the customization and development of motors as well as sensors. The developed robot will be used for MR safe and MR compatibility test, which is a new generation of 7.0T MRI developed by Sino Canada Health Engineering Research
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Institute. The follow-up work will be involved in the integration between the intervention robotand control system, network environment building, etc. Our aims are focus on developing stereotactic neurosurgical robotic assistant system with MR-compatible, high accuracy and low price, which could benefit both surgeons and patients.
T1-5/T1-7 Strong Correlations in Cold atoms (DAMOPC/DCMMP) | Corrélations fortes dans les atomes froids (DPAMPC/DPMCM) / 2549
Conductivity of a perfect crystal
Author: Joseph Thywissen1
1 University of Toronto
Corresponding Author: [email protected]
Dissipation of electrical current in typical metals is due to scattering off material defects and phonons. But what if the material were a perfect crystal, and sufficiently stiff or cold to eliminate phonons– would conductivity become infinite? We realize an analogous scenario with atomic fermions ina cubic optical lattice, and measure conductivity. The equivalent of Ohm’s law for neutral particles gives conductivity as the ratio of particle current to the strength of an applied force. Our measure- ments are at non-zero frequency (since a trapping potential prevents dc current flow), giving the low-frequency spectrum of real and imaginary conductivity. Since our atoms carry no charge, we measure particle currents with in-situ microscopy, with which both on- and off-diagonal response is visible. Sum rules are used to relate the observed conductivity to thermodynamic properties such as kinetic energy. We explore the effect of lattice depth, temperature, interaction strength, andatom number on conductivity. Using a relaxation-time approximation, we extract the transport time, i.e., the relaxation rate of current through collisions. Returning to the initial question, we demonstrate that fermion-fermion collisions damp current since the lattice breaks Galilean invariance.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2550
2 - Determination of Activity Concentrations in Selected Rock Samples from Quarry Sites in Ibadan, Nigeria
Author: Babatunde Adebo1
1 Lead City University
Corresponding Author: [email protected]
Measurement of natural radioactivity in rock is very important to determine the amount of change in the natural background activity with time as a result of any ra- dioactive releases. It is very important to monitor radioactive substances released to the environment for proper environmental protection. The aim of this work is to investigate the concentration of radioactive substance in selected rock samples in a quarry site in Ibadan for the purpose of safety assessment. Fifteen rock samples, each of mass 1kg were collected from the quarry site inIbadan and then hammered into pieces before being crushed into very ne grain. The desired samples were then stored in polythene sachets for 28 days so as to reach secular equi- librium. Samples were thereafter taken to the Nuclear Physics Laboratory for counting and analysis. The gamma analysis was performed on a 76mm X 76mm Sodium Iodide (Thallium doped) NaI (TL) scintillation counter detector photomultiplier. Results ob- tained showed that the ranges of the activity concentrations of 40K, 238U, 232Th in the rock samples are 87:058:46 to 174:452:56, 8:251:46 to 21:351:25 and 1:020:32 to 10:63 0:71Bqkg 1. Activity concentrations obtained are less than that of United
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Nations Scientic Committee on Eects of Atomic Radiation Report (UNSCEAR) report 2000 which indicated the worldwide activity concentration of 40K, 238U and 232Th within the ranges 140-850, 17-60 and 11-64Bqkg 1 and mean 400, 35 and 30Bqkg 1 respectively. Keywords: Natural Radioactivity, activity concentration, secular equilibrium, rock samples 1Lead City University, Ibadan 1
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2551
Updates from SNOLAB
Author: Erica Caden1
1 SNOLAB
Corresponding Author: [email protected]
Answering many of the outstanding questions in astroparticle and subatomic physics today requires the ultra-quiet environment provided by deep underground research facilities. SNOLAB is Canada’s deep underground facility, at a depth of 2 km in Vale’s Creighton mine near Sudbury, Ontario. In this environment, cosmic radiation induced backgrounds are minimized to levels allowing the oper- ation of sophisticated experiments. SNOLAB is home to a number of experiments that make use of this unique location. The facility is growing, and the number of projects hosted is increasing. I’ll review the new construction projects and the status of the currently running experiments, as well as improvements to the infrastructure.
W1-7 Detectors for Particle Physics (DAPI/PPD) | Détecteurs pour la physique des particules (DPAI/PPD) / 2552
Direct plasmon production from Thomson scattering in Super- CDMS silicon detectors
Author: Émile Michaud1
1 Université de Montréal
Corresponding Author: [email protected]
SuperCDMS (Super Cryogenic Dark Matter Search) is an experiment for the direct detection of dark matter with great sensitivity to Compton scattering at low energies where electron binding andcrys- tal structure affect Compton scattering spectra. We can take advantage of the SuperCDMS detector sensitivity to these low energies to look for plasmon production from Thomson scattering in silicon. Using the adiabatic local-density approximation (ALDA) of the dynamic structure factor S(q, ω) of silicon, we expect the differential cross section of plasmon production from Thomson scattering to be high enough so that our detectors could be the first in the world to detect these plasmons. We will report on the status of the search for a signal from plasmon production.
R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2553
WITHDRAWN- Water Cherenkov Detector Calibration for Super- Kamiokande and Hyper-Kamiokande
Author: Patrick de Perio1
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1 TRIUMF
Corresponding Author: [email protected]
The future Hyper-Kamiokande neutrino oscillation experiment has the potential to discover CPvio- lation in the lepton sector. In order to distinguish the small difference between neutrino and antineu- trino oscillation, the experiment is designed to achieve an unprecedented statistical uncertainty of 3%. Correspondingly, a systematic uncertainty below this level is necessary for a robust and precise measurement. Water Cherenkov detector calibration will become one of the limiting systematics and will require significant improvements. This talk will review the various Super-Kamiokande calibra- tion data, including laser and radiation sources, and Canadian initiatives on photosensor characteri- zation and photogrammetry for detector geometry determination. These initiatives are expected to bolster our low-level understanding and facilitate a bottom-up modeling of the detector that consis- tently describes all data. A prototype Hyper-K intermediate water Cherenkov detector is planned to be installed in a CERN beamline to test these calibration techniques and demonstrate a percent-level understanding.
T1-4 Direct Detection of Dark Matter (PPD) | Détection directe de la matière sombre (PPD) / 2554
SuperCDMS SNOLAB: the search for low-mass dark matter parti- cles
Author: Silvia Scorza1
1 SNOLAB
Corresponding Author: [email protected]
Cosmological and astrophysical observations indicate that the vast majority of the universe’s matter content is made out of dark matter. Over the past decades, the physics community has largely focused on searching for dark matter within the 10 GeV-1 TeV mass range (WIMPs). The absence of a discovery has motivated us to broaden our experimental search program andto look for lighter dark matter particles in the <10 GeV mass range. The forthcoming SuperCDMS SNOLAB experiment will test a range of low mass dark mattermodels using cryogenic silicon and germanium detectors. In this talk, recent results and detector R&D efforts will be described, as well as the latest status and prospects for the new SuperCDMS SNOLAB effort.
R1-3 Condensed Matter Theory II (DCMMP) | Théorie de la matière condensée II (DPMCM) / 2555
Valley filters, accumulators, and switches induced in graphene quantum dots by lines of adsorbed hydrogen atoms
Authors: Mohammadhadi Azari1; George Kirczenow1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
We present electronic structure and quantum transport calculations that predict conducting channels induced in graphene quantum dots by lines of adsorbed hydrogen atoms to function as highly effi- cient, experimentally realizable valley filters, accumulators, and switches. The underlying physics is an interesting property of graphene Dirac point resonances (DPRs) that is revealed here, namely, that an electric current passing through a DPR mediated conducting channel in a given direction
Page 82 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
is carried by electrons of only one of the two graphene valleys. Our predictions apply to lines of hydrogen atoms adsorbed on graphene quantum dots that are either free standing or supported on a hexagonal boron nitride substrate.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2556
37 - Ion beam injection and extraction simulations in TITAN’s cooler Penning trap
Authors: Roshani Silwal1; Brian Kootte2; Stefan F. Paul3; Gerald Gwinner2; Ania A. Kwiatkowski1
1 TRIUMF 2 University of Manitoba 3 University of Heidelberg
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
The Cooler Penning Trap (CPET) at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) facility was developed with a goal to further enhance the precision capabilities of TITAN’s mass measurement Penning trap (MPET) for short-lived radioactive isotopes. The sub-ppb precision of the MPET can be further increased by an order of magnitude or more by using highly charged ions extracted from the TITAN electron beam ion trap as the mass precision scales with the charge state of the species. However, the energy spread induced in these ions by charge breeding may introduce some additional challenges to these mass measurements. By cooling the highly charged ions with room temperature electrons in the CPET, the energy spread can be reduced from a few 10 eV/q to 1 eV/q. We conducted ion injection and extraction simulations with the SIMION package to evaluate the optimum operational conditions of the off-line/development setup and for the integration into the on-line setup. The injection and extraction characteristics of the ion beam were evaluated and the focusing optics were optimized for maximum ion transmission to and from CPET. The effect of different initial ion beam conditions in the trap and various trapping schemes in the optimization of the final beam properties were studied to match the transversal and longitudinal emittance of the cooled ion bunches extracted from CPET to the acceptance of MPET. The simulations showed that the transmission efficiency is sensitive to the axial potential applied to the nested wells,the extraction potential and the length of the ion bunch.
M1-2 Exploring the energy frontier (PPD) | Explorer la frontière d’énergie (PPD) / 2557
Search for Magnetic Monopoles and High Electric Charge Objects in the ATLAS Detector
Author: Ana Maria Rodriguez Vera1
1 York University (CA)
Corresponding Author: [email protected]
The concept of a magnetic charge, analogous to electric charge, has been around formanycen- turies. Paul Dirac formally introduced the concept into electromagnetism and quantum mechanics concluding that, If observed, Magnetic Monopoles would potentially explain the quantization of the electric charge and complete the symmetry between electricity and magnetism in Maxwells’ equations. Since then there have been many searches for Magnetic Monopoles through different experimental techniques, none of which have given conclusive results on the matter. We present a search for Dirac Magnetic Monopoles and High Electric Charge Objects in the ATLAS detector from 13TeV pp collisions at the LHC. Detection is based on the particles’ characteristic high ionization,
Page 83 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
penetration distance and lack of shower. A data driven method called the ABCD method is used to estimate the background in the signal region. Model independent efficiency maps are implemented to reduce the need for computationally intensive simulations.
R2-8 Ultracold Neutrons (DNP/PPD) | Neutrons ultrafroids (DPN/PPD) / 2558
Progress on ultracold neutrons at TRIUMF
Authors: Jamieson Blair1; for the TUCAN CollaborationNone
1 University of Winnipeg
Corresponding Author: [email protected]
The TRIUMF Ultracold Advanced Neutron (TUCAN) source, a collaboration between Canadian and Japanese researchers has had two successful ultracold neutron (UCN) runs, demonstrating the pro- duction of 70,000 UCN in standard operation. The UCN are produced by cooled spallation neutrons down-scattering in energy in He-II, and at UCN temperatures can be guided in beam-pipes toexper- imental areas. The first experiment planned for the TUCAN source is a search for a neutron Electric Dipole Moment (nEDM) which is a T-violating process, and through CPT invariance would imply a new source of CP-violation. A new horizontal UCN source that in its standard operation will pro- duce two orders of magnitude more UCN than the current source, that can handle larger heat loads, and has improved cold moderation, has been designed. This talk will review the progress onthe TUCAN facility, its recent run in Fall 2018, its plans for an improved UCN source, and status of the planning for the nEDM experiment at TRIUMF.
T2-10 Nuclear Instrumentation (DNP) | Instrumentation nucléaire (DPN) / 2559
Development of multi-detector systems for radiation measure- ments at Simon Fraser University
Author: Melanie Gascoine1
1 Simon Fraser University
Corresponding Author: [email protected]
Gamma ray spectroscopy in the Nuclear Science Laboratory (NSL) at Simon Fraser University (SFU) is used for nuclear structure studies, neutron activation analysis, and environmental radioactivity monitoring. The current detection system is the Germanium detector for Elemental Analysis and Radioactivity Studies (GEARS), and consists of a single high purity germanium (HPGe) detector which is housed in a lead box for passive shielding. Sensitivity is limited especially at low energies due to background radiation and Compton scattering. The detection capabilities of the NSL canbe improved through the use of Compton suppression and time coincidence measurements. The time coincidence method allows for the possibility of gamma-gamma, beta-gamma, and alpha-gamma measurements that will help distinguish between events of interest, and background radiation or events caused by contaminant induced reactions. However a multi-detector system is required to take advantage of this method. The 8-pi spectrometer, recently acquired by SFU from the ISAC-I facility at TRIUMF, isasetof 20 HPGe detectors equipped with BGO Compton suppressors arranged in a spherical array. The 8-pi is being rebuilt to its original design of a high multiplicity spectrometer to be used in fission studies. All photomultiplier tubes and 18 out 25 HPGe are currently operational. HPGe detectors operate at liquid nitrogen (LN2) temperatures and the required cooling system is being expanded from GEARS to support the 8-Pi. Implementation of the data acquisition (DAQ) system poses a greater challenge as it requires 332 channels for the BGO photomultipliers plus 20 channels for the
Page 84 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
HPGe detectors in order to operate the full array. A DAQ based on the TIG-10 and VF-48 digitizers is under development. In the interim, a subset of six 8-Pi Compton Suppressed Spectrometers (CSS) will be arranged in a cubic array for the purpose of time coincidence measurements. A frame has been designed and will be constructed by the SFU machine shop. The HPGe detectors will be cooled using the LN2 cooling system intended for the full 8-pi array. The High Voltage distribution for the CSS shield photomul- tipliers built for the 8-pi will be used. Additionally NIM/CAMAC-based DAQ can be adapted from the existing GEARS system to allow operation of six CSS for the cube. Progress towards completion of this array will be presented and discussed.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2560
62 - EMPHATIC detector development
Author: Blair Jamieson1
Co-author: for the EMPHATIC collaboration
1 University of Winnipeg
Corresponding Author: [email protected]
The next generation of long-baseline neutrino oscillation experiments that will search for CP-violation of neutrions will be limited by systematic uncertainties. One of the systematic uncertainties that needs to be reduced is the neutrino flux uncertainty, which can be improved with more precise mea- surements of the pion and kaon production by beams of protons. The EMPAHTIC experiment plans to use the Fermilab test beam to measure pion and kaon production using beams of protons with momenta between 1 GeV/c and 120 GeV/c to measure the forward production rates of pions and kaons that can be used to improve neutrino flux production simulation. A compact spectrometer has been designed that includes silicon strip detectors for tracking, a permanent dipole magnet for momentum measurement, an aerogel ring imaging cherenkov detector for pion versus kaon separa- tion, a time of flight detector, and a lead glass calorimeter. This talk will discuss the detector design, and the development of components of the detector.
R2-4 Testing Fundamental Symmetries II (DTP/PPD/DNP) | Tests de symétries fondamentales II (DPT/PPD/DPN) / 2561
An Improved Extraction of the Vud CKM Matrix Element
Author: Kyle Shiells1
1 University of Manitoba
Corresponding Author: [email protected]
The CKM matrix of the Standard Model (SM) is aunitary 3×3 matrix which holds information on how strongly the various quark flavours couple to each other. Consequently, nature’s adherence tothe SM can be tested by the normalization condition of its rows. |Vud| = 0.97417(21) is a dominant term 2 2 2 in the first row unitarity condition: |Vud| + |Vus| + |Vub| = 1, and thus carries more weight than its 2 neighbours. The largest source of its uncertainty comes from a troublesome, model-dependent radiative correction: the γW box. I outline a new way to calculate this Feynman diagram using dispersion relations, which lead to a more realistic value of Vud and its uncertainty estimate.
Page 85 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
M2-8 General Relativity I (DTP) | Relativité générale I (DPT) / 2562
Laws of Black Hole Thermodynamics in Semiclassical Gravity
Author: Bruno Arderucio Costa1
1 University of British Columbia
Corresponding Author: [email protected]
We show how the zeroth, first, and second laws of black hole thermodynamics emerge from a generic semiclassical theory of gravity. The zeroth law is a kinematic property of bifurcate Killing horizons. It depends neither on details of the semiclassical coupling nor on the dynamics of gravity. The first law is established for stationary spacetimes for which a Hamiltonian can be defined. The second law is established in “piecewise stationary” spacetimes, roughly speaking a stationary spacetime that is disturbed and eventually returns to a different stationary sate. Black hole entropy is consistently defined in the Noether charge approach, and the entropy for the matter in its exterior isthevon Neumann entropy of the quantum fields. These results elucidate the meaning of these lawsand strongly support the interpretation of black hole entropy as an account of the information that is hidden behind the horizon.
M1-10 Materials synthesis and characterization I (DCMMP) | Synthèse et caractérisation de matériaux I (DPMCM) / 2563
Effect of temperature on plasmonic resonances in semiconduc- tors and metals
Authors: Vaibhav Thakore1; Janika Tang2; Kevin Conley3; Tapio Ala-Nissila4; Mikko Karttunen5
1 Department of Applied Mathematics and Center for Advanced Materials and Biomaterials Research, Western Uni- versity 2 QTF Center of Excellence, Department of Applied Physics, Aalto University School of Science, Espoo, Finland 3 QTF Center of Excellence, Department of Applied Physics, Aalto University School of Science, Finland 4 QTF Center of Excellence, Department of Applied Physics, Aalto University School of Science, Aalto, Espoo, Finland; Department of Physics, Brown University, Providence, Rhode Island, USA; Interdisciplinary Centre for Mathe- matical Modelling, Department of Mathematical Sciences, Loughborough University, Loughborough, UK 5 Departments of Applied Mathematics and Chemistry; Center for Advanced Materials and Biomaterials Research, Western University, London, Ontario, Canada
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Plasmonically enhanced absorption or scattering of radiation on the mesoscale forms the basisof promising applications in a wide variety of fields such as: biosensing, photothermal therapy, photo- catalysis, solvothermal chemistry, energy harvesting, magnetic recording for data storage, control of radiative heat transfer and so on. In a majority of the applications based on plasmonics, the noble metals - gold (Au) and silver (Ag) - have been the materials of choice. However, it is also now widely acknowledged that these materials suffer from problems of poor thermal and chemical stability ac- companied by significant dissipative losses under high-temperature conditions. These issues have thus prompted a quest for materials with better thermoplasmonic properties. In this regard, semi- conductor particles have lately attracted a lot of attention because they exhibit low ohmic losses, are thermochemically more stable, and exhibit highly tunable plasmonic resonances through bandgap engineering, control over dopant concentration and dielectric environment. Here, we will present results from our recent work on the multiscale modeling of plasmonically enhanced control of heat radiation using semiconductor inclusions [1, 2]. Furthermore, a comparison of the size-dependent thermoplasmonic behavior of indirect and direct bandgap semiconductor particles of undoped silicon (Si) and gallium arsenide (GaAs), respectively, with the metallic (Au) particles that are characterized by a complete absence of the bandgap will also be presented [3].
Page 86 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
References
1. Vaibhav Thakore, Janika Tang, Kevin Conley, Tapio Ala-Nissila, Mikko Karttunen, Thermoplas- monic response of semiconductor nanoparticles – A comparison with metals, Adv. Theory Sim. 1800100, 2018. 2. Janika Tang, Vaibhav Thakore, Tapio Ala-Nissila, Plasmonically enhanced reflectance of heat radiation from low-bandgap semiconductor microinclusions, Sci. Rep. 7, 5696, 2017. 3. Kevin Conley, Vaibhav Thakore, Tapio Ala-Nissila, Plasmonically Enhanced Spectrally-sensitive Coatings for Gradient Heat Flux Sensors, PIERS 2018, Toyama, Japan, August 1-4, 2018.
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2564
87 - Concentration of Cells and Elimination of Extraneous Back- ground Signals in Laser-Induced Breakdown Spectroscopy to Iden- tify, Differentiate and Detect Bacteria
Authors: Jeremy Marvin1; Alexandra Paulick1; Emma Blanchette1; Sydney Sleiman1; Steven Rehse1
1 University of Windsor
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Our lab has been investigating the use of laser-induced breakdown spectroscopy (LIBS) for the rapid identification of bacteria in clinical specimens. The ability to rapidly identify harmful pathogens in such specimens is crucial for initiating appropriate treatment of infectious diseases that can kill within hours of the onset of symptoms. Current laboratory techniques can take as long as 24-72 hours for a positive identification. Our research program is attempting to reduce that time to minutes. Sample preparation methods utilized in our procedure include common materials and equipment that could be easily implemented in clinical settings. The current protocol involves the collection of bacteria using pathology swabs, centrifuging the suspension through a custom-fabricated cone device and concentrating the bacterial cells in a liquid suspension onto a small circular deposition area 1 mm in diameter upon a nitrocellulose filter medium. A pulse of high-intensity laser light focused onto the circular deposition allowsa sensitive measurement of the elemental composition of the cells, leading to the detection and identification of the bacteria. By reducing the cell concentration in various suspensions, thelimit of detection may be calculated. Laser ablation of the filter medium and other elemental contaminants yields a non-zero background signal when a control experiment is performed in the absence of bacterial cells. This poster will present our efforts to identify exactly what the sources of this non-bacterial signal are, test other types of filter media which may contribute to reduced background signal and toadd preparation steps to the protocol, which might reduce or eliminate this undesired background signal. In addition, the investigation of how chemometric algorithms such as Partial Least Squares Discriminant Analysis and Discriminant Function Analysis can be used to differentiate between the LIBS emission spectra obtained from 4 different bacterial species will be discussed.
W1-8 Probing and controlling matter with light II (DCMMP) | Sonder et contrôler la matière avec de la lumière II (DPMCM) / 2565
Cavity Spintronics: Foundations and Applications of Spin-Photon Hybridization
Author: Michael Harder1
Page 87 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 Department of Physics, Kwantlen Polytechnic University
Corresponding Author: [email protected]
Light-matter interactions lie at the heart of condensed matter physics, providing physical insightinto material behaviour while enabling the design of new devices. Perhaps this is most evident in the push to develop quantum information and spintronic technologies. On the side of quantum informa- tion, engineered light-matter interactions offer access to and control of quantum states. Meanwhile insights into spin-photon manipulation are driving the development of spintronic technologies. In this context the discovery of hybridization between ferromagnets and cavity photons has ushered in a new era of light-matter exploration at the crossroads of quantum information and spintronics. The key player in this rapidly developing field of cavity spintronics is a new quasiparticle, the cavity- magnon-polariton (CMP). In this talk I will describe the defining characteristics of the CMP and recent spintronic applications. In the last few years we have developed a comprehensive theoretical framework of spin-photon hybridization, which has revealed the electrodynamic origin of hybridiza- tion. As I will describe, this model is supported by our experimental observations and is motivated by a deeper microscopic description. Based on this foundation in depth experimental investigations of the coupled spin-photon system have been performed. For example, we have found that hybridiza- tion will influence spin current generated through the spin pumping mechanism, demonstrating a firm link between spin-photon coupling and spintronics. Furthermore, several in-situ coupling con- trol mechanisms have been revealed and utilized to perform non local spin current manipulation over distances of several centimetres. These many recent developments represent only the first stepsin this exciting frontier of condensed matter research lying at the crossroads of magnetism and cavity quantum electrodynamics.
Papers Published During Thesis Work (Selected) M. Harder et al. PRL 121, 137203 (2018) (Editor’s Suggestion) M. Harder et al. PRB 95, 214411 (2017) L. Bai, M. Harder et al. PRL 118, 217201 (2017) H. Maier-Flaig, M. Harder et al. APL 110, 132401 (2017) M. Harder et al. PRB 94, 054403 (2016) M. Harder et al. Science China 59, 117511 (2016) H. Maier-Flaig, M. Harder et al. PRB 95, 054433 (2016) L. Bai, M. Harder et al. PRL 114, 227201 (2015) (Editor’s Suggestion)
W2-4 Fields and Strings II (DTP) | Champs et cordes II (DPT) / 2566
Computing Conformal Blocks through Geodesic Witten Diagrams
Author: Jonathan Classen-Howes1
1 McGill University
Corresponding Author: [email protected]
Conformal blocks are used to study the correlation functions of conformal field theories; quan- tum field theories which are invariant under conformal transformations. A consideration affect- ing the use of conformal blocks is that they can be difficult to compute efficiently. The anti-de Sitter/conformal field theory correspondence, a conjectured duality with wide applications intheo- retical physics, provides a way to overcome this difficulty. It does so by addressing computationally- complicated conformal blocks through more manageable geodesic Witten diagrams, which are their geometric configuration within the dual anti-de Sitter space. The resulting integral representations of the conformal blocks provide a more efficient way to compute them numerically than the tradi- tional series expansion techniques. This presentation will provide a background to the calculation of conformal blocks through geodesic Witten diagrams within the context of the AdS/CFT correspon- dence, and discuss current research on their ensuing integral representations.
Page 88 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
W1-5 ”Bertram Brockhouse and the History of Canadian Neutron Scattering” (DHP) | ”Bertram Brockhouse et l’histoire de la diffusion de neutrons canadienne” (DHP) / 2567
The Canadian Neutron Beam Centre at Chalk River
Author: John Root1
1 Fedoruk Centre
Corresponding Author: [email protected]
Building on a foundation of scientific excellence, through the pioneering work of Bertram Brock- house and others, the “Neutron and Solid State Physics” branch of Atomic Energy of Canada Lim- ited, at Chalk River, transitioned to a modern international user facility, beginning in the 1980s. The program was transferred to the National Research Council of Canada in 1997, from which time the “Canadian Neutron Beam Centre” thrived and supported a growing community of research partic- ipants from across Canada and abroad, involving more than 800 individuals in the final five years of operation with six neutron beam lines at the NRU reactor. This presentation will follow the ups and downs of the Canadian Neutron Beam Centre from about 1985 to 2018. We shall touch on some scientific highlights, technical achievements, and our Canadian approach to user access. Finally, we shall summarize the 30-year quest to replace the NRU reactor with a modern neutron source, as well as to establish a new framework to manage our national program for materials research with neutron beams, in decades to come.
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2568
Characterizing the SNOLAB radiation environment
Authors: Deepak Tiwari1; PICO CollaborationNone
1 PICO Collaboration, Universite de Montreal
Corresponding Author: [email protected]
The flux of thermal neutrons, fast neutrons, and gamma photons, arising due to radioactivity inthe materials surrounding the detector, constitute the principle component of the radiation environment for the underground experiments at SNOLAB. The flux of fast neutrons comprising (α, n) and spon- taneous fission constitutes a significant background and the SNO collaboration estimated thisflux − to be ∼ 4000 neutrons m−2 day 1(2πsr)−1, with an unknown spectrum. PICO-2L, operating as a very sensitive low background fast neutron detector with shielding removed, measured this fast neutron flux for ∼ 20 live-days. We performed a simulation of neutron propagation for PICO-2L to understand the spectral shape of the fast neutron flux, the detector sensitivity and the effect of the drift environment on neutron propagation. Through comparing and correlating the simulations with PICO-2L and previous measurements for gamma fluxes, slow and fast neutrons, and under- standing the radioactive contamination of the materials around the detector, a coherent model for the radiation environment in the SNOLAB drifts can be constructed.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2569
51 - Precision characterization of the linear-zigzag transition in ultracold trapped ion crystals
Author: Brendin T Chow1 Co-authors: Mahdi Qaryan 1; Jie Zhang 2; Paul C Haljan 1
Page 89 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 Department of Physics, Simon Fraser University 2 Interdisciplinary Center of Quantum Information, National University of Defense Technology
Corresponding Authors: [email protected], [email protected], [email protected]
In a linear Paul ion-trap, the structural transition from a 1-D linear chain of ions to a 2-D zigzag structure, known as the linear-zigzag transition, is a well-known behavior for crystals of laser cooled, trapped ions. Here we present the first studies of the linear-zigzag transition at ultracold temper- atures following cooling to near the ground-state of motion. We characterize the transition using Raman sideband spectroscopy , revealing the shape of the effective potential near the critical point and thereby the nature of the transition. In an ideal linear Paul trap, the linear-zigzag transition is associated with the onset of a symmetric double-well potential that is indicative of its continuous nature . Experimentally in our setup, we observe a bias in the double-well potential near the critical point; we attribute this to small asymmetries in the ion trap . We also observe a shift in thecritical point of approximately 0.5% from the value predicted in the pseudopotential approximation for the ion trap , consistent with the effect of micromotion on the ions in the radio-frequency trap.Ata technical level, our spectroscopic measurements of the linear-zigzag transition are enabled by a high level of long-term trap stability over the duration of data acquisition. This work sets the stage for measurements of coherent effects near the critical point.
M1-11 Probing and controlling matter with light I (DCMMP) | Sonder et contrôler la matière avec de la lumière I (DPMCM) / 2570
Terahertz conductivity measurements of MnSi
Authors: Laleh Mohtashemi1; F. Michael BartramNone; Amir FarahaniNone; Eric KarhoNone; Theodore L. Monchesky2; J. Steven Dodge3
1 Simon Fraser University 2 Department of Physics, Dalhousie University, Canada 3 Department of Physics, Simon Fraser University, Canada
Corresponding Authors: [email protected], [email protected]
We will present time-domain terahertz spectroscopy measurements of the optical conductivity of MnSi thin films. Measurements cover a temperature range T = 5−300 K and a frequency rangeν= 0.1−4 THz. We find that at low temperatures and frequencies, the scattering rate is proportional to both the square of the temperature and the square of the frequency, as predicted Fermi liquid theory. As the temperature increases further, the system loses quasiparticle coherence, while the plasma frequency inferred from a Drude fit decreases dramatically.
W1-4 Advances in Nuclear and Particle Theory (DTP/PPD/DNP) | Progrès en théorie nucléaire et théorie des particules (DPT/PPD/DPN) / 2571
Asymptotic Safety in the Conformal Hidden Sector
Authors: Tom Steele1; Robert Mann2; Fred Sage3; Zhi-Wei Wang4
1 U of Saskatchewan 2 U of Waterloo 3 U Saskatchewan 4 CP3 and U Waterloo
Page 90 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
The notion of asymptotic safety is combined with conformal invariance in an extension oftheStan- dard Model. Renormalization group equations are used as a bridge to connect asymptotic safety UV boundary conditions and EW/TeV scale physics in the context of a leptophobic U(1)′ model. A broad selection of UV boundary conditions are formulated corresponding to differing AS scenar- ios. An asymptotically-safe scenario is found with very strong predictive power, allowing unique determination of most of the parameters in the model. Interrelationships among the couplings, the UV transition scale of the fixed point, and other phenomenological features of the model will be discussed.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2572
52 - Electron plasma studies for a cooler Penning trap at TITAN
Author: Stefan Felix Paul1
Co-authors: Brian Kootte ; Roshani Silwal 1; Gerald Gwinner 2; Jens Dilling 3; Anna Kwiatkowski 1
1 TRIUMF 2 University of Manitoba 3 triumf/UBC
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
The TITAN facility at TRIUMF performs mass measurements of rare isotopes, e.g. to test thestan- dard model. Charge breeding the radionuclides can increase the attainable measurement precision; however, it may increase the ions’ energy spread, thereby negatively impacting the mass measure- ment. To leverage the full benefits of Penning trap mass spectrometry with highly charged ionswe are implementing a cooler Penning trap (CPET) into the TITAN system. In CPET the charge-bred ions will be trapped with an electron plasma in a nested potential and sympathetically cooled. The ion cooling rate and the lowest attainable ion temperature critically depend on the electron density distribution and the impact of the electron space charge on the effective trapping potential. Electrons will be injected into the 7T magnetic field, undergo cyclotron radiation cooling, and form a room-temperature plasma at the trap centre. To study the plasma behavior we simulated it with the particle-in-cell code WARP. A limiting factor for simulations on electron plasmas in high mag- netic fields are the extremely small time steps needed to sample the fast cyclotron gyro-motion. By using WARP’s Drift-Lorentz particle mover the time steps could be increased above the electron cy- clotron period reducing the required computation times by more than two orders of magnitude. We initialized the electrons as a cylindrical column along the magnetic field axis with a thermal velocity distribution and let them evolve into a near-equilibrium state. We simulated the resulting electron density and distribution for several potential shapes. From these results we evaluated the space charge and its effect on the trapping potentials as well as the confinement limits of the electron trap. We determined suitable trapping potentials for plasmas with different numbers of electrons. These simulation results will enable a fine tuning of the voltages applied to the trap electrodes for optimal cooling performance.
M2-4 Emerging investigators in bioimaging and medical applications of optics (DPMB/DAMOPC) | Chercheurs émergeants en bioimagerie et applications médicales de l’optique (DPMB/DPAMPC) / 2573
Analysis of Plasmonic and Plasma Assisted Photoacoustic Response
Page 91 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts from Metallic Nanostructures Irradiated by Fast and Ultrafast Laser
Author: Ali Hatef1
1 Nipissing University
Corresponding Author: [email protected]
Nanotechnology is rapidly developing as an enabling technology for introducing new highly per- formant theragnostic tools for biomedical applications. Recently, plasmonic nanostructures (PNs) have shown a great potential for providing an effective method in this field of research and appli- cations. PNs present very peculiar optical properties related to the presence of a large optical ab- sorption cross-section due to the collective oscillation of the conduction electrons by incident laser field known as localized surface plasmon resonance (LSPR). The PNs are also capable ofenhanc- ing the incident laser field in the form of scattered near field for even an off-resonance irradiation where the incident laser wavelength is far away from LSPR. If the intensity of the incident laser is large enough, this field enhancement capability can be employed to generate a highly localized free electron (plasma) in the vicinity of the particles. The energy deposition in generated plasma can be considered as an energy source for photothermal ablation therapy, photoacoustic tomography, and light-controlled drug release. In this presentation we will present a model that will serve as a design tool for simulating ultrashort pulsed laser interaction with PNs in water for such applications. This tool is built based on the following physical phenomena that couples: 1) optical properties of the PN obtained from simulation of electromagnetic wave interaction with PN and coupled through resistive heating due to laser pulse to; 2) two temperature model to analyze transient heat transfer in ultrafast regime and temperature increase calculation, where temperature is used as a coupling parameter to; 3) plasma dynamics and 4) structural mechanics analysis for linear thermal expansion, stress and strain calculation for the input as a boundary condition in acoustic-structure interaction for; 5) acoustic pressure wave propagation modeling.
M2-10 Soft condensed matter II (DCMMP) | Matière condensée molle II (DPMCM) / 2575
Nanoscale Surface Morphology Induced by Poor Solvents on Glassy Polymer Films
Author: Tiana Trumpour1
Co-authors: James Forrest 1; Adam Raegen 1
1 University of Waterloo
Corresponding Author: [email protected]
Thin polymer films are commonly used as samples in numerous areas of materials physics. Tech- niques applied to the preparation and application of thin films, including etching and nanolithogra- phy, often involve the addition of a solvent to the polymer surface. It is currently understood that there exist two classifications of polymer solvents. Good solvents are used to fully dissolve apoly- mer film while poor solvents are thought to have no lasting effects on a surface. However, recent research has shown that some poor solvents significantly impact polymer film surfaces and pro- duce surface morphology on the nanoscale. In this study, polystyrene thin films of number average molecular weights ranging from 8000 g/mol to 545000 g/mol were produced through spin casting onto a silicon substrate. The films were then exposed to various poor solvents for differing time durations. The change in surface morphology was examined with an atomic force microscope and analyzed to determine the extent to which solvents change the polymer surface. It is shown that poor solvents produce a nanoscopic surface morphology with a characteristic length scale that is independent of the solvent used. The characterization results will allow for discussion of polymer surface morphology.
Page 92 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
T1-1 Soft Matter AM-1 (DCMMP) | Matière molle AM-1 (DPMCM) / 2576
Crystallization Studies of Highly Monodisperse Oligomeric Poly(Ethylene Oxide)
Authors: Junjie Yin1; Adam Raegen1; James Forrest1
1 University of Waterloo
Corresponding Authors: [email protected], [email protected], [email protected]
Polydispersity can significantly affect the physics properties of polymers. In this study we showthe differences in poly(ethylene oxide) oligomer crystallization between monodisperse and polydisperse samples as an example. Commercial polymers even with a low polydispersity index (PDI) of about 1.01, still contain a rather broad distribution of different molecular weights. In this study we pro- duced highly monodisperse PEO through evaporative purification of aMn 600 PEO sample, achiev- ing a PDI significantly lower than the as purchased sample, as measured by mass spectroscopy. Melt- ing temperatures were obtained using differential scanning calorimetry (DSC). Based on the Gibbs Thomson relation, we show that during crystallization, some monodisperse samples form crystal lamellae with both extended chains and once-folded chains. In contrast, polydisperse samples have been shown to only contain extended chains in the crystal form. The fact that we are able totune the melting temperature through annealing treatment on the crystal validates the existence of both folded and extended chains in the monodisperse samples.
M2-1 Interaction Between Matter and Light (DAMOPC) | Interaction de la matière et de la lumière (DPAMPC) / 2577
Light-cone like spreading of correlations in the Bose-Hubbard model at strong coupling
Authors: Matthew Fitzpatrick1; MALCOLM KENNETT2
1 Simon Fraser University 2 SIMON FRASER UNIVERSITY
Corresponding Authors: [email protected], [email protected]
We study the spreading of correlations in space and time after a quantum quench in the Bose Hubbard model. We derive equations of motion for the single-particle Green’s function within the contour- time formalism, allowing us to study dynamics in the strong coupling regime. We discuss the nu- merical solutions of these equations and calculate the single-particle density matrix for quenches in the Mott phase. We demonstrate light-cone like spreading of correlations in the Mott phasein one, two, and three dimensions and calculate propagation velocities in each dimension. Our results show excellent agreement with existing results in one dimension and demonstrate the anisotropic spreading of correlations in higher dimensions. We also discuss how our results can be extended to disordered systems.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2578
77 - Position resolution in the DEAP-3600 dark matter experi- ment
Author: Joseph Willis1
Page 93 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 University of Alberta
Corresponding Author: [email protected]
DEAP-3600 is a direct detection dark matter experiment using a cryogenic liquid Argon target mass. The detector is situated within a water tank and placed 2 kilometres underground at SNOLABto shield it from outside sources of radiation. However, contaminants on the inner surface of the spher- ical acrylic vessel (AV) can trigger the detector and must be removed using data analysis. A cut is applied to remove such events that reconstruct near the surface of the AV, but the efficiency of this cut is strongly dependent on the accuracy of our reconstruction algorithms and so it is vital to un- derstand the resolution of these fitters. This presentation details the development of a data-driven method for measuring the position resolution of a charge-based reconstruction algorithm. In Febru- ary 2019 the collaboration released a first year paper with 758 tonne-day exposure, in which we showed a resolution of ~20 mm for events near the detector surface.
T4-7 Optical Spectroscopy and control (DAMOPC) | Spectroscopie optique et contrôle (DPAMPC) / 2579
Laser cooling of antihydrogen using pulsed VUV radiations
Author: Takamasa Momose1
1 The University of British Columbia, ALPHA Collaboration
Corresponding Author: [email protected]
The ALPHA (Antihydrogen Laser PHysics Apparatus) Collaboration at CERN is engaged in precision tests of fundamental symmetries between matter and antimatter. A primary goal is to study the optical spectroscopy of antihydrogen, the bound state of an antiproton and positron. Recent progress in the synthesis and confinement of antihydrogen has resulted in the availability for spectroscopy of a thousand trapped anti-atoms at a time. The two-photon 1S-2S transition frequency has been measured to a relative precision of 2 × 10−12, only some three orders of magnitude away from the precision of normal hydrogen atom. In order to further improve the measurement accuracy, we are now implementing laser cooling of trapped antihydrogen via the 1S- 2P transition using a nano- second VUV laser pulses. The 1S-2P manifold contains a cycling transition, presenting the possibility of laser cooling of antimatter, but the control of the 1S- 2P excitation is challenging due tothelack of convenient VUV laser source. We have developed an all solid state, narrow linewidth, nano- second pulsed laser system at 121.6 nm and successfully demonstrated that the 1S- 2P transition of antihydrogen can be controlled with a precision of better than several tens of MHz at 121.6 nm.This accuracy is enough to cool antihydrogen from the present 500 mK temperature to a few tens of mK. We will discuss how the cooling of trapped atoms with pulsed laser radiation works, and will also report the status and outlook for laser cooling of antihydrogen.
M1-1 Test of Fundamental Physics with Atoms (DAMOPC) | Tests de physique fondamentale avec des atomes (DPAMPC) / 2580
A new electron gun for the TITAN-EBIT
Author: Kilian Dietrich1
Co-authors: Jens Dilling 2; Oliver Kester 1; Ish Mukul 1; Anna Kwiatkowski 1
1 TRIUMF 2 triumf/UBC
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Page 94 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
One method to improve our understanding of nuclear physics, for example the nuclear structures within atoms, is performing high-precision mass measurements of ions. Penning traps are widely used for mass spectroscopy with the lowest uncertainty and they can reach a precision of m/m~1*10−9 with radioactive ion beams. This precision can be further improved by using highly charged ions (HCI) of the isotope of interest because m/m directly depends on the ions’ charge state q. These HCIs can be created with charge breeding inside an Electron Beam Ion Trap (EBIT) where high elec- tron current densities are used to knock out electrons of trapped ions via electron impact ionization. This boost in measurement precision has been successfully demonstrated at the TITAN facility at TRIUMF. At TITAN, the EBIT high voltage has recently been upgraded to allow 65 keV electron beams. To bet- ter take advantage of the higher energies, we are upgrading the electron gun of the EBIT to achieve maximum current densities and therefore the shortest breeding times and the highest charge states. In order to get the optimized setup, the electron beam properties of the electron gun were simulated using the Field Precision Trak software. With modifications to the electromagnetic optics, acom- pression factor of 45 for the beam radius and thereby current densities of 1800 A/cm2 were achieved in the trapping region of the EBIT for a 1.5 A cathode at 30 keV. For maximal experimental flexibility, three cathode sizes were simulated at different beam energies. Furthermore the geometry and design will also simplify routine maintenance. We will present the results of our simulations and the new design. The new electron gun will enable us to better perform high-precision mass measurements of nuclides with short half lives.
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2581
Resonance Ionization Laser Ion Source – pure radioactive ion beams & in-source laser spectroscopy
Authors: Maryam Mostamand1; Ruohong Li2; Jekabs Romans3; Bianca Reich4; Jens Lassen5
1 University of Manitoba- TRIUMF 2 TRIUMF 3 KU Leuven 4 TRIUMF, U Heidelberg, Germany 5 TRIUMF, Simon Fraser university, U of M
Corresponding Authors: [email protected], [email protected], [email protected], ruo- [email protected], [email protected]
In-source laser resonance ionization spectroscopy aims to drastically increase the resonant laser ionization efficiency for element species. This can be achieved by finding auto-ionizing (AI)states suitable for laser resonance ionization. Isotope separator on-line (ISOL) facilities such as the isotope separator and accelerator (ISAC) at TRIUMF produce a wide variety of exotic radio-isotopes for experiments on nuclear structure, astrophysical processes and material sciences. These facilities are ideally suited for fundamental research on nuclear structure but also are the place to perform atomic spectroscopy in search of energy levels of radioactive elements. The study of atomic transitions along long chains of isotopes of a particular element allows also to study the evolution of nuclear charge radii as a function of neutron number via the hyperfine interaction. The TRIUMF resonance ionization laser ion source (TRILIS) is an efficient tool to provide pureion beams using the element selective resonance ionization process and an instrument for ultra-sensitive atomic spectroscopy by means of laser resonance ionization. . For laser ionization scheme development on stable isotopes and ion source development, an off-line test stand was built and is being operated in parallel to the on-line laser ion source. This allows to conduct the required instrumentation developments for forefront experiments with rare isotopes in the service of nuclear physics experiments.
M2-1 Interaction Between Matter and Light (DAMOPC) | Interaction de la matière et de la lumière (DPAMPC) / 2582
Page 95 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Gas Cell Based on Hollow-Core Fiber for Trace Gas Detection
Authors: Joshua Trevisanutto1; Gautam Das1
1 Lakehead University
Corresponding Authors: [email protected], [email protected]
Hollow-core photonic crystal fiber (HC-PCF) was used to develop a gas cell, which was incorporated in an Intracavity Absorption Spectroscopy (ICAS) system for the detection of gas at sub-ppmv levels of concentration. One drawback of using long lengths of HC-PCF is the relatively long time required to allow the gas sample to fill the entire cell. By segmenting the fiber there will be multiple points of entry for the gas to enter. The effect of segmenting the HC-PCF on sensitivity and fill/evacuation times will be examined. The working principle of the ICAS system will also be presented, along with a comparison between both segmented and un-segmented HC-PCF cells. The motivation for developing this system is to manufacture a compact and remotely operated system at a relatively low cost, which could be placed in a fertilized agriculture field to monitor the emission of greenhouse gases (e.g., N2O). Besides the HC-PCF, all other optical components used in the system are from the telecommunication industry which reduces the cost of manufacturing the system. A fiber Bragg grating (FBG) was used to select the lasing wavelength of the cavity. The lasing wavelength chosen for the system corresponds to the absorption line of the gas species of interest. When monitoring N2O, the system operates at a wavelength of 1522 nm. The wavelength was chosen in order to avoid strong absorption lines from other gases of the atmosphere. The research was financially supported by Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Foundations for Innovations (CFI), Ontario Center of Excellence (OCE) and Nutrien.
R2-3 Quantum Optics and Ion traps (DAMOPC) | Optique quantique et pièges d’ions (DPAMPC) / 2583
Photonic Device for Gas Detection
Authors: Gautam Das1; Joshua Trevisnutto2
1 Gautam 2 Lakehead University
Corresponding Authors: [email protected], [email protected]
We have developed a photonic device for the detection of gases at sub-ppmv levels of concentration using a modified Intra Cavity Absorption Spectroscopy (ICAS) technique [Technique for thedetec- tion of trace gases using intracavity fiber laser absorption spectroscopy (IFLAS), G Das - US Patent 9,705,277, 2017]. In the new ICAS technique, the system was operated near the laser threshold con- dition in order to increase sensitivity. The device can be used for environmental monitoring. The novelty and the working principle of the system, along with some recent experimental results based on both Acetylene (C2H2) and Nitrous oxide (N2O) gases will be presented. The research was finan- cially supported by Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Foundations for Innovations (CFI), Ontario Center of Excellence (OCE) and Nutrien.
T4-1 Soft Matter PM-2 (DCMMP) | Matière molle PM-2 (DPMCM) / 2584
Statistical physics of a driven nanocolloid coupled to a fluid heat bath
Authors: Vaibhav Thakore1; Carlos Mejia-Monasterio2; Tapio Ala-Nissila3; Mikko Karttunen4
Page 96 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 Department of Applied Mathematics and Center for Advanced Materials and Biomaterials Research, Western Uni- versity, London, Ontario Canada 2 Laboratory of Physical Properties TAGRALIA, Technical University of Madrid, Madrid, Spain 3 QTF Center of Excellence, Department of Applied Physics, Aalto University School of Science, Aalto, Espoo, Finland; Department of Physics, Brown University, Providence, Rhode Island, USA; Interdisciplinary Centre for Mathe- matical Modelling, Department of Mathematical Sciences, Loughborough University, Loughborough, UK 4 Departments of Applied Mathematics and Chemistry and Center for Advanced Materials and Biomaterials Research, Western University, London, Ontario, Canada
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Stochastic thermodynamics of mesoscale systems has been extensively studied using a dragged col- loidal particle in a trap as a model system. The colloid is assumed to be a massive Brownian particle that undergoes stochastic motion governed by a Langevin-type equation. The Langevin description of the colloidal motion however completely ignores the hydrodynamic coupling of the colloid to the heat bath. Here, we present results for the stochastic thermodynamics of a dragged nanocolloid hydrodynamically coupled to a fluid heat bath. The motion of the colloidal nanoparticle ismodeled using a hybrid fluctuating lattice Boltzmann (FLB) and molecular dynamics (MD) method thatac- counts for full nonlinear hydrodynamic effects [1, 2, 3]. The mesoscopic FLB-MD method employed in our simulations for the dragged colloidal particle in a trap allows testing of the fluctuation theo- rems in the truly transient regime of system evolution [1, 3]. FLB-MD also explicitly allows a study of the irreversible work done on the colloid-solvent system in the form of heat dissipation or entropy production in the fluid that has so far been impossible to achieve even in experiments. References
1. S. T. T. Ollila, C. Denniston, M. Karttunen, and T. Ala-Nissila, Fluctuating lattice-Boltzmann model for complex fluids, J. Chem. Phys. 134, 064902 (2011) 2. M.M.T. Alcanzare, S.T.T. Ollila, V. Thakore, A.M. Laganapan, A. Videcoq, M. Cerbelaud, R.Fer- rando, and T. Ala-Nissila, Shape and scale dependent diffusivity of colloidal nanoclusters and aggregates, Eur. Phys. J. Special Topics 225, 729–739 (2016) 3. M. M. T. Alcanzare, V. Thakore, S. T. T. Ollila, M. Karttunen and T. Ala-Nissila, Controlled propul- sion and separation of helical particles at the nanoscale, Soft Matter, 13, 2148 (2017)
T3-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-1 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-1 (DPN) / 2585
Methods to constrain thermonuclear rates (by and for John D’Auria)
Author: Christopher Wrede1
1 Michigan State University
Corresponding Author: [email protected]
An accreting compact star in a binary system can generate periodic thermonuclear runaways on its surface. In the case of a white dwarf star, the result is a classical nova, which enriches the interstellar medium with newly synthesized nuclides. In the case of a neutron star, a detectable burst of X-rays is emitted. Nucleosynthesis and energy generation in these events depends on thermonuclear reaction rates, which are especially challenging to measure directly in the laboratory when the reactants are radioactive. John D’Auria led a collaboration to surmount this challenge; in the process, he included and inspired a new generation of scientists. Some of John’s earlier work showed that beta decay is also an effective method to determine thermonuclear rates indirectly. A new program ofbeta decay experiments to constrain thermonuclear rates is being pursed at the National Superconducting Cyclotron Laboratory by a collaboration including one of John’s mentees. In particular, the Gas
Page 97 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Amplifier Detector with Germanium Tagging (GADGET) system, developed to measure veryweak low-energy beta delayed proton emission branches and gamma rays, is now operational.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2586
25 - Level Attraction and Synchronization in Hybridized Magnon- Photon Systems
Authors: Michael Harder1; Ying Yang2; Bimu Yao3; Chenhui Yu4; Jinwei Rao2; Yongsheng Gui2; Robert Stamps2; Can-Ming Hu2
1 Department of Physics, Kwantlen Polytechnic University 2 Department of Physics and Astronomy, University of Manitoba 3 State Key Laboratory of Infrared Physics, Chinese Academy of Sciences 4 Jiangsu Key Laboratory of ASIC Design, Nantong University
Corresponding Author: [email protected]
The recent emergence of cavity-spintronics [1] has garnered intense interest from both the quantum information and spintronics communities, the former inspired by the enhanced coherence rates of ferromagnetic systems and the latter motivated by new avenues for spin current control. Indeed myriad technological developments have already been revealed, such as novel memory architec- tures [2], microwave to optical frequency conversion techniques [3] and non local spin current ma- nipulation [4]. These developments have all been based on the fact that, due to the hybridization between microwave cavity photons and magnetic excitations, cavity-spintronic devices act as excel- lent transducers. More specifically, spin-photon hybridization manifests itself as level repulsion due to electrodynamic phase correlation between the spin and photon subsystems, and is characterized by the emergence of a gap in the eigenspectrum [5]. Interestingly, in analogue cavity optomechanic systems another form of hybridization, level attraction, also exists [6], which is deeply connected to the physical ideas of exceptional points, PT symmetry and synchronization. In this talk I will dis- cuss our recent observation of level attraction in a coupled spin-photon system [7]. This newform of coupling is characterized by synchronization-like behaviour of the hybridized modes, and origi- nates in a novel cavity-Lenz effect which leads to a dissipative interaction. The cavity-Lenz effect occurs independently of dissipation rate or interaction strength and it is even possible to perform continuous in-situ tuning between level attraction and level repulsion. Therefore the discovery of level attraction in hybridized magnon-photon systems paves a new path for utilizing light-matter coupling in cavity-spintronic and quantum magnonic applications, while at the same time providing a new playground for the exploration of many intriguing physical ideas. [1] M. Harder and C.-M. Hu, Solid State Physics 69, 47 - 121 (2018). [2] X. Zhang et al., Nat. Comm. 6, 8914 (2015). [3] R. Hisatomi et al., Phys. Rev. B 93, 174427 (2016). [4] L. Bai, et al., Phys. Rev. Lett. 118, 217201 (2017). [5] L. Bai, et al., Phys. Rev. Lett. 114, 227201 (2015). [6] N. Bernier et al., Phys. Rev. A 98, 023841 (2018). [7] M. Harder, et al., Phys. Rev. Lett. 121, 137203 (2018).
M2-9 Magnetism and heavy fermions II (DCMMP) | Magnétisme et fermions lourds II DPMCM) / 2587
Finite Size Kosterlitz-Thouless Transition in Fe/W(001) Ultrathin Films
Author: Jordan Atchison1
Page 98 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Co-authors: David Venus 1; Amanjot Bhullar 1; Bryce Norman 1
1 McMaster University
Corresponding Authors: [email protected], [email protected]
Idealized two-dimensional ferromagnetic films are predicted to undergo a Kosterlitz-Thouless (KT) transition that involves topological excitations termed vortices. Whereas the idealized system is isotropic within the plane (2DXY symmetry), real ferromagnetic films grown on single crystal sub- strates display anisotropy and finite-size effects that can lead to more complicated behaviour. In this work, magnetic susceptibility measurements of 3-4ML Fe/W(001) films with four-fold in-plane anisotropy were compared to theoretical predictions for a finite-size KT transition, and found to be in excellent quantitative agreement. Susceptibility measurements on many films grown inde- pendently in ultrahigh vacuum were made in situ using the magneto-optic Kerr effect (MOKE). Since the susceptibility signal can become complicated by dissipation caused by domain walls at low temperatures, the analysis concentrated on the high temperature, paramagnetic tail of the sig- nal where quantitative theoretical predictions apply. The paramagnetic tail was fit to the distinctive form predicted by KT theory for a gas of unbound vortex/antivortex pairs: χ(T)=χ0 exp(B/(T/TKT-1)a), using a four-parameter fit. An analysis of 16 suscepti- bility signals from 12 independently grown films gave fitted parameters of a=0.50±0.03 and B=3.48±0.16, in excellent agreement with the predicted values of a=1/2 and 3.2 < B < 3.8. In about one-third of the films, the dissipative signal Im(χ) was very small, so that the peak of Re(χ) occurred closeto the finite size transition temperature, TC(L). In these cases, the fitted values oftheKT transition temperature, TKT, were tens of K below TC(L), which is quan- titative agreement with finite size KT theory. In contrast, fitting to a power law typical ofasecond order phase transition, χ(T)=χ0(T/Tγ -1)γ, gives an effective critical exponent of γ=3.7±0.7 and places the transition temperature Tγ ~10K below the peak temperature. Both of these results are unphysical.
R2-8 Ultracold Neutrons (DNP/PPD) | Neutrons ultrafroids (DPN/PPD) / 2588
Measurements of the first polarized ultracold neutrons at TRI- UMF
Author: Sean Hansen-Romu1
1 University of Manitoba
Corresponding Author: [email protected]
During an experimental run in fall 2018 with the ultracold neutron (UCN) source at TRIUMF we created polarized UCN by passing them through a thin magnetized iron foil. This talk will describe results of measurements of the UCN polarization and spin flipping efficiency measured by the TRI- UMF Ultracold Advance Neutron (TUCAN) Collaboration using a pair of these foils and a pair of identical spin flippers. TUCAN is a collaboration between Canadian and Japanese researchers to search for sources of CP-violation in the form of a fundamental neutron Electric Dipole Moment (nEDM). The nEDM changes the Larmor frequency of neutrons precessing in a magnetic andelec- tric field by an amount proportional to the electric field. Measuring this frequency difference isatthe heart of the nEDM Measurement and uses UCNs in two electric fields state, parallel and antiparallel to a magnetic field. The statistical error in the nEDM measurement can be minimized byachieving the highest possible neutron polarization and spin state analysis efficiency. A simultaneous spin analyzer (SSA) system increases the spin analysis efficiency of UCNs by reducing the time that one of the spin states is stored above the detector. The spin analyzer components we characterized are a part of a SSA system that is being tested for the future nEDM measurement.
M2-1 Interaction Between Matter and Light (DAMOPC) | Interaction de la matière et de la lumière (DPAMPC) / 2589
Page 99 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Novel AFM-Intermodulation Technique for Nanoscale Character- ization of Surface Properties
Author: Nisha Rani Agarwal1
1 University of Ontario Institute of Technology
Corresponding Author: [email protected]
Most phenomena or interactions whether they be physical, chemical or biological in nature take place at the nanoscale. Hence, materials under study should be characterized for various properties such as structural, mechanical, optical and chemical at high resolution. Not many techniques are capable of nanoscale measurements. Development of novel techniques for this purpose is possible by employing recent advances in technology. One such advancement is the development of Multi- frequency Lock-in Amplifier (MLA) that outperforms conventional lock-in amplifiers in many ways. This MLA is able to simultaneously detect more than 20 close by frequencies with no interference from each other. Thus, making it possible for incorporating MLA to develop new techniques. In this research program, a novel method has been developed in order to measure the elastic prop- erty in combination with structural property at the nanoscale which is achieved by intermodulation Atomic Force Microscopy (ImAFM) while driving the tip at two frequencies. This results in genera- tion of other frequencies from which the force curve can be reconstructed to be fitted with various force models in order to extract the elastic values. A very important consideration to be made is that the handling of force curves and data processing not only depends on the surface properties of the sample but also depends on the morphology of the samples and on the tip properties. ImAFM is particularly of interest for measuring visco-elastic properties i.e probing nanoscale properties of biomaterials.
W1-5 ”Bertram Brockhouse and the History of Canadian Neutron Scattering” (DHP) | ”Bertram Brockhouse et l’histoire de la diffusion de neutrons canadienne” (DHP) / 2590
Bert Brockhouse and the Early History of Canadian Neutron Scat- tering - a personal view
Author: J. Michael Rowe1
1 University of Maryland and NIST
Corresponding Author: [email protected]
Neutron scattering in Canada began when Brockhouse, Myer Bloom and D. G. Hurst measured neu- tron scattering in highly absorbing Materials (Cd, Sm, Gd) by transmission measurements attheNRX reactor in Chalk River. Following this, the goal was to study differential scattering cross-sections, and work began in earnest in 1954, using a “primitive” triple-axis spectrometer at NRX. This began the tremendous spurt of results, with improved monochromators and later the more powerful NRU reactor becoming available. Many people contributed over the next 10 years, and Brockhouse left AECL and Chalk River for McMaster University in 1962. The Canadian neutron scattering program continued to set the standards worldwide, although the opening of the Institut Laue Langevin in France rapidly became the foremost center in the world. These developments will be explored in the light of Bert’s leadership and instrument development, but the emphasis throughout will remain people.
T1-1 Soft Matter AM-1 (DCMMP) | Matière molle AM-1 (DPMCM) / 2591
A combined local-macroscopic approach to investigate plasticity of athermal amorphous solids
Page 100 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Celine Ruscher1
Co-author: Joerg Rottler 2
1 Stewart Blusson Quantum Matter Institute 2 UBC
Corresponding Authors: [email protected], [email protected]
Understanding the origin of plasticity in amorphous systems remains a challenging problem. The absence of long-range order prevents a clear definition of structural defects and therefore of their evolution during deformation. Furthermore, the interplay with temperature or the rate of deforma- tion makes their dynamics difficult to describe. However, for systems slowly deformed in athermal conditions, plastic flow occurs through local re- arrangements of particles. These shear transformation zones (STZ) are not independent andtheir interactions lead to intermittent collective rearrangements in the form of avalanches [1]. Recently, a scaling description of the yielding transition based on the depinning transition has been proposed [2]. The predictions of this theory have been validated by mesoscopic elasto-plastic models and particle scale simulations in the steady-state flow. However, conflicting points of views have emerged regarding the phenomenology in the transient regime [2-4]. In this work, we investigate the emergence of plasticity by considering molecular simulations of a Lennard-Jones glass former. In the athermal quasistatic shear limit, we study in a complemen- tary way deformations at the macroscopic scale and at the local scale by using the frozen matrix approach. In particular, the evolution of the scaling properties of stress and strain distributions with deformation will be investigated. [1] M.L.Falk and J.S. Langer, PRE, 57(6):7192–7205, 1998 [2] J.Lin et al. PNAS, 40, 111, 2014 [3] K. M. Salerno and M. O. Robbins , PRE, 88(6):062206, 2013 [4] H.G.E Hentschel et al. PRE, 92(6) 062302, 2015
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2592
17 - Effect of CT Injection on Dusty Plasma in the STOR-M Toka- mak
Author: Nathan Nelson1
1 University of Saskatchewan
Corresponding Author: [email protected]
The vast majority of power consumed by humanity now (2019) is produced through the burningof some form of fossil fuel. Even if environmental impacts are neglected, this current supply is projected to last on the order of 100 years at the current usage rate. For this reason humanity requires an alternative, safe and reliable high output energy source. For this reason, fusion and related plasma physics research is invaluable. There are however, multiple problems to address with fusion devices at this point. One such problem is fuelling.
In order to successfully fuel an operating fusion device, a mechanism is required which can deliver that fuel to the core/bulk of the generated plasma. A candidate for this type of fuelling is the injection of a Compact Torus (CT). The CT is essentially a self confined ball of plasma (a plasmoid). Utilizing the University of Saskatchewan Tokamak (STOR-M) with the CT injection system, the effects of enhanced plasma confinement and lifetime are to be studied. Utilizing pulsed operation of theCT, repetitive fuelling cycles will be analysed as well. Though, fuelling is one issue, unwanted particles in the plasma is another reality that must be dealt with.
Page 101 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
In order to simulate a dirty fusion plasma, machined tungsten dust will be introduced into STOR-M. The effects of the dust in the plasma will be controlled by a separate vacuum chamber. Thetungsten dust will be released in STOR-M, both with and without the use of the CT injector. This will allow for quantitative understanding of plasmoid interaction and test the viability of the CT as a fuelling technique. Due to the change in plasma behaviour with CT injection, a non-trivial interaction of the plasma under fuelling is expected even in the presence of the tungsten dust. References: [1] A. Pant. “Repetitive Operation of the University of Saskatchewan Compact Torus Injector”. Mas- ters dissertation. University of Saskatchewan. 2009. [2] A. Rohollahi. “Experimental Studies Using Compact Torus Injector”. Ph.D dissertation. Univer- sity of Saskatchewan. 2017. [3] T. Onchi, Y. Liu, M. Dreval, D. McColl, S. Elgriw, D. Liu, T. Asai, C. Xiao and A. Hirose. “Effects of compact torus injection on toroidal flow in the STOR-M tokamak”. Plasma Physics and Controlled Fusion. vol. 55. 2013
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2593
63 - Photoneutron calibration of SuperCDMS detectors
Author: Emanuele Michielin1
1 University of British Columbia
Corresponding Author: [email protected]
The SuperCDMS (Cryogenic Dark Matter Search) experiment has pioneered the use of low-temperature solid-state detectors to search for dark matter particle candidates. Detectors operating in CDMSlite mode allowed searches for particles with masses down to about 2 GeV/c2 by pushing the analysis threshold to nuclear recoil energies down to about 0.5 keV. However, one of the main uncertainties for the sensitivity for such searches is the lack of an accurate understanding of the nuclear recoil energy scale in this low spectral range. During the SuperCDMS Soudan operations, data was collected using two low-energy photoneutron sources, 88Y and 124Sb placed next to a 9Be target. I will describe the implementation and the result of a likelihood analysis used to determine the nuclear recoil energy scale at low energy of the Ge detectors from these data sets. This work will help to improve the sensitivity of the upcoming SuperCDMS SNOLAB experiment, where upgraded detectors will allow searches for particles with masses down to about 0.5 GeV/c2.
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2594
The Barrel Scintillator Veto for the ALPHA-g experiment
Author: Nicolas MASSACRET1
Co-authors: Andrea Capra 2; Konstantin Olchanski 2; Lars Martin 1; Lu Philip 1; Makoto Fujiwara 2; Miles Consta- ble 1; Pierre-Andre Amaudruz 2; Robert Henderson 1
1 TRIUMF 2 TRIUMF (CA)
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], nmas- [email protected], [email protected], [email protected], [email protected], [email protected]
Page 102 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
The main objective of the ALPHA-g experiment is to determine the behavior of the anti-matter when it is subjected to the Earth’s gravitational field. At the center of this experimental setup, anti- hydrogen atoms are created and trapped in the magnetic field produced by an octupole magnet. Once the magnetic field is lowered, these anti-atoms are released and move in accordance with gravity. Annihilation occurs when anti-atoms meet the walls of the trap. This annihilation produces pions, which are tracked by the second layer of the experiment: a radial Time Projection Chamber (rTPC) filled with an Argon/CO2 mixture. This first detector determine the path of the pions,and thus the original position of the annihilations. The rTPC is sensitive to other energetic particles coming from outside of the experiment, likemuons produced by cosmic rays which cross the rTPC at a significant rate. In order to distinguish the tracks produced by these particles from the annihilation products, a barrel scintillator has been installed around the rTPC to act as a veto. This second detector is constituted by 64 plastics scintillator bars. Each bar has a length of2.6mand a trapezoidal cross-section. When a particle crosses this barrel, scintillation light is produced by the scintillator and propagates up to the ends of the bar where Silicon Photomultipliers (SiPM) transform it into an electrical signal. This signal is then processed by the electronic read-out to determine the arrival time of the light on the SiPM, and the amount of photons received. This information allows us to determine when and where a particle has interacted with a bar, and thus if it comes from inside (annihilation) or outside of the barrel. The design and realization of this scintillator apparatus were punctuated by several challenges. The space constraints were high and the barrel had to be self-supported without external structure. To ensure a proper rejection of the external particles, the read-out electronics had to be optimized to obtain a time resolution of the order of 200 ps. This barrel scintillator was designed and assembled at TRIUMF, before being moved at CERN forits commissioning in September 2018. After being integrated to the rest of the experiment, the whole set-up was tested with antiproton annihilations.
W2-4 Fields and Strings II (DTP) | Champs et cordes II (DPT) / 2595
Entanglement entropy on the noncommutative sphere
Author: Joanna Karczmarek1
1 UBC
Corresponding Author: [email protected]
Entanglement entropy in a Quantum Field Theory is an interesting geometric observable which provides information on how degrees of freedom at different points are coupled. Thus, entanglement entropy can be used as a tool for probing the non-locality structure of theories on fuzzy spaces. I will describe how geometric entanglement entropy can be studied in a scalar field theory on a fuzzy sphere and compare the results to SYM theory in flat space, as previously obtained holographic picture.
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2596
14 - DC magnetron discharge used for nanoparticle growth: com- parison of particle- in-cell simulations with experimental mea- surements
Author: Lenaic Couedel1
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Co-authors: Cecile Arnas 2; Alebia Chami 3
1 University of Saskatchewan/CNRS 2 CNRS, Aix-Marseille Univ., PIIM 3 CNRS, Aix-Marseille Univ, PIIM
Corresponding Authors: [email protected], [email protected], [email protected]
1. Introduction The formation of nanoparticles (NP) in glow discharges has been for a long time a subject ofhigh interest. In radio-frequency (RF) discharges, NP growth and its effect on discharge parameters have been studies using reactive [1,2], and by sputtering of the electrodes [3]. In direct-current (DC) sputtering glow discharge, NP formation, dynamics and transport has also been studied using different cathode materials [4-8]. Since the mid-1990’s, RF and DC magnetron-sputtering aggregation sources are commonly used to produce metal nanoparticles [9, 10]. They normally consist of a high-pressure plasma chamber connected to a low pressure expansion chamber in which a beam of NP can be filtered and collected. NPs are formed in the high-pressure side of the MS-AS by cathode sputtering. However, very few studies are devoted to the characterization of the magnetron plasma in which NPs are growing and the link between plasma parameters and NP growth dynamics. 2. Experimental setup The experiments were performed in an argon DC unbalanced magnetron discharge having a3”di- ameter tungsten cathode. The cathode was facing a grounded anode and the inter-electrode distance could be changed from 5 cm to 10 cm. Either two glass half-cylinders or two stainless steal half cylin- ders were used to confine the plasma. A 1 cm gap was kept between them for optical diagnostics and radial Langmuir probe measurements. An argon pressure between 10 Pa and 40 Pa (5 sccm gas flow) was set during the experiments. The discharge system was contained in a cylindrical vacuum chamber of 30 cm diameter and 40 cm length. A regulated power supply was used to bias the cath- ode. The discharge current was kept at a constant value (from 100 mA to 500 mA). Under thechosen operating conditions, the cathode was sputtered and tungsten NPs could be grown. 3. Particle-in-cell simulations The simulation were performed using the VSIM software from TechX corporation [11]. 2D3Vsimula- tions in cylindrical geometry were preformed. The simulation box was cut in 512×512 cells. Dirichlet boundary conditions were used for the cathode (V=Vbias) and the anode (V=0 V), For the side wall, Dirichlet boundary condition were used to simulate the metallic cylinder (V=0 V). For the glass cylinder a dielectric was added to the simulation.The nominal density was set to 1012 cm-3 and the particle weight was variable. A time step of 10-12 s was used and the simulations were run for a few millions time steps until equilibrium was reached. 4. Results The simulated potential and density profiles were compared to experimental measurements. The influence of the sputtered atoms on the discharge properties were also investigated. A particular attention is given to the influence of the sputtered metal on the electron temperature. Resultsare correlated to NP growth dynamics. References [1] M. Cavarroc, et al., Phys. Rev. Lett. 100, 045001 (2008). [2] I. Stefanovic, N. Sadeghi, and J. Winter, J. Phys. D: Appl. Phys. 43, 152003 (2010). [3] D. Samsonov and J. Goree, Phys. Rev. E 59, 1047 (1999). [4] G. M. Jellum and D. B. Graves, J. Appl. Phys. 67, 6490 (1990). [5] C. Arnas, et al. , Phys. Plasmas 20, 013705 (2013). [6] Kishor Kumar K., L. Couëdel, and C. Arnas, Phys. Plasmas 20, 043707 (2013). [7] L. Couëdel, Kishor Kumar K., and C. Arnas, Phys. Plasmas 21, 123703 (2014). [8] S. Barbosa, et al., J. Phys. D: Appl. Phys. 49, p. 045203 (2016). [9] H. Haberland, et al., J. Vac. Sci.Technol. A 12, 29250 (1994). [10] T. Acsente,et al., Mat. Lett. 200, 121 (2017). [11] C. Nieter, and J. R. Cary, J. Comp. Phys. 196, 448 (2004)
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T3-1 Soft Matter PM-1 (DCMMP) | Matière molle PM-1 (DPMCM) / 2597
Investigating Novel Anion-Exchange Membranes via Scattering and Simulation
Author: Eric Matthew Schibli1
Co-authors: Steven Holdcroft 1; Barbara Frisken 1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected]
While perfluorinated polymers dominate the commercial fuel cell industry, hostility to catalysts, difficult and expensive synthetic routes, and challenging disposal hamper wide adoption offuel cell technology and impede further development. Hydrocarbon-based membranes utilize simple, well-developed synthetic routes that allow for rapid material development. We have investigated a promising series of sterically hindered methylated imidazole-based ionenes utilizing a combination of lab-scale X-ray scattering and OPLS-AA-based molecular dynamics simulations to elucidate the morphology of these materials
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2598
CUTE Status and Plans
Author: Ryan Underwood1
1 Queen’s University
Corresponding Author: [email protected]
There is strong astrophysical and cosmological evidence for a new kind of matter knownasdark matter, which does not interact via the electromagnetic or strong forces. The SuperCDMS experi- ment searches for dark matter particle candidates using cryogenic germanium and silicon detectors. The next generation of SuperCDMS is scheduled to start operating at SNOLAB in 2020. Beforethis facility is ready, the Cryogenic Underground TEst Facility (CUTE) will come online to test Super- CDMS detectors underground at SNOLAB, providing a low-background, low cosmogenic activation environment. The facility will have the capacity to hold up to six of the standard SuperCDMS detec- tors. The CUTE cryostat has a faster turnaround time to test detectors in an efficient mannerand allows the study of detector performance well before the main experiment is ready. Given the low background of the facility as well as the expected threshold of the new detectors, the CUTE facility will have an opportunity to search for low-mass dark matter with the new SuperCDMS detectors. When SuperCDMS comes online, CUTE will be used to perform detailed characterizations of the detectors and test new R&D detectors. This talk will present the CUTE facility and discuss thestatus underground at SNOLAB.
R2-7 Nuclear Structure IV (DNP) | Structure nucléaire IV (DPN) / 2599
WITHDRAWN - Shape coexistence in the Pb region: A systematic study of the even 188−200Hg with GRIFFIN
Authors: B. Olaizola1; A. B. Garnsworthy1
Co-authors: F. A. Ali 2; Corina Andreoiu 3; Gordon Ball 4; Nikita Bernier 4; Harris Bidaman 5; V. Bildstein 2; M. Bowry 1; Roger Caballero-Folch 4; Iris Dillmann ; Greg Hackman 4; P. E. Garrett 6; Badamsambuu Jigmeddorj 5; A.
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I Kilic 5; Andrew MacLean 5; Yukiya Saito 7; james smallcombe ; Carl Svensson 5; Joseph Turko 5; K. Whitmore 8; Tammy Zidar 5
1 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 2 Department of Physics, University of Guelph, Guelph, Ontario 3 Simon Fraser University 4 TRIUMF 5 University of Guelph 6 Department of Physics, University of Guelph, Guelph, Ontario 7 The University of British Columbia / TRIUMF 8 Department of Physics, Simon Fraser University, Burnaby, British Columbia
Corresponding Authors: [email protected], [email protected], [email protected], co- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Shape coexistence is a unique phenomenon of the atomic core in which the nucleus displays intrin- sically different shapes in a small energy range. Two of the main observables which have emerged as model-independent probes of this phenomenon are the measurement of transition strengths, in particular B(E2) and ρ2(E0) [1]. These transition strengths are particularly sensitive to the wavefunc- tions of the states they connect, and thus are one of the most stringent tests the different theoretical models used to describe nuclei. The n-deficient Pb region (to the south-west of Z=82, N=126) is characterized by clear examplesof shape coexistence [1]. A large odd-even, and ground state-isomer, staggering of the isotope shifts was observed in the light Hg (Z=80) isotopes that expresses the differently shaped potentials existing in these nuclei causing deformation [2]. Only recently, a COULEX experiment obtained detailed information about shape coexistence for 182−188Hg [3]. Still, there are plenty of key elements not yet measured, especially in the transitional isotopes between the stable 200Hg and the beginning of the midshell 190Hg. In these transitional isotopes, the ground and intruder configurations are still reasonably separated in energy (the relative energy of the intruder states has a parabola-shape with a minimum at 182Hg), thus reducing to negligible levels the mixing between the two bands. These isotopes present a good opportunity to benchmark the normal ground-state configuration without the perturbations experienced in the lighter isotopes, thus simplifying the comparison with different theoretical calculations. In order to characterize the evolution of the transitional Hg isotopes, a systematic study of the de- cay of the n-deficient 188−200mTl into Hg has been performed using the GRIFFIN spectrometer at TRIUMF-ISAC. Data collected with the ancillary LaBr3(Ce) array, have been analyzed with the Gen- eralized Centroid Difference Method (GCDM) [4] to precisely measure lifetimes of all thefirst2+, 4+ as well as some negative-parity and non-yrast states. The extracted B(E2) values are compared with different IBM calculations while the negative-parity band is interpreted in comparison witha particle-rotor model. High statistics results for lifetimes, conversion-electrons, angular correlations and precise branching ratios, which all help in forming a complete picture of the band structure of these isotopes, will be discussed. [1] K. Heyde, J. L. Wood, Rev. Mod. Phys. 83, 1467(2011). [2] B. A. Marsh et al. N ature Physics 14, 1163–1167 (2018) [3] N. Bree et al. Phys. Rev. Lett. 112, 162701, (2014). [4] J. M. Regis et al. NIMA 726, 191 (2013).
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2600
Modelling Cherenkov in DEAP-3600
Author: Courtney MielnichukNone
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The DEAP-3600 experiment searches for spin-independent interactions of weakly interacting mas- sive particle (WIMP) dark matter candidates. The detector utilizes a 3279 kg mass of liquid argonas the dark matter target, which is contained in a spherical acrylic vessel. Results from the analysisof data taken during the first year of operation were released in February 2019. The analysis ofthis758 tonne-day exposure requires a thorough understanding and modelling of all backgrounds capable of mimicking a WIMP signal. DEAP-3600 uses pulse shape discrimination to distinguish between nuclear recoils, which produce prompt scintillation signals, and electromagnetic recoils, which produce slow scintillation signals. Most backgrounds in DEAP-3600 produce slow scintillation signals whereas WIMPs would generate fast scintillation signals. Cherenkov light, similar to WIMPs, produces very fast pulses of light and it is therefore important to characterize and understand Cherenkov events in the detector. Validation of Monte Carlo simulation has been performed by comparing simulation results to data taken using DEAP-3600. This talk will focus on the modelling of background events produced by Cherenkov in acrylic, including details of understanding optical interfaces and parameters in Monte Carlo simulation.
R2-8 Ultracold Neutrons (DNP/PPD) | Neutrons ultrafroids (DPN/PPD) / 2601
Improving the sensitivity of the neutron electric dipole moment experiment at TRIUMF
Author: Steve Sidhu1
1 SFU/TRIUMF
Corresponding Author: [email protected]
The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration is currently developing anew ultra-cold neutron (UCN) facility with the main scientific objective to measure the neutron electric dipole moment (nEDM). To conduct the nEDM search experiment, the neutrons must be transported to a precession chamber, be stored, and deposited into the detectors efficiently. This is especially important, since neutron EDM experiments are statistically limited. The presentation will describe the methods for optimising various components of the UCN source, UCN transport hardware, and the nEDM apparatus to minimise the total experimental run time.
R2-6 Topological and 2D materials (graphene, etc) (DCMMP) | Matériaux topologiques et 2D (graphène, etc.) (DPMCM) / 2602
Violation of Ohm’s law in a Weyl metal
Author: Jeehoon Kim1
Co-author: Dongwoo Shin 1
1 Pohang University of Science and Technology
Corresponding Authors: [email protected], [email protected]
In 1827, German scientist Georg Ohm published Ohm’s law of constant electrical resistance in metals. Ohm’s Law is one of the unbreakable rules of experience for nearly two centuries after its discovery. It was recently discovered that Ohm’s law, which never seemed to be broken, was not established in BiSb alloys. The BiSb alloy whose energy band is twisted becomes a topological metal (Weyl metal)in the absence of time reversal symmetry. When an electric field is applied in a certain direction, some of the electrons move in the direction of the electric field without resistance. The density of electrons flowing without resistance changes with the applied electric field. As a result, no currentflows in a Weyl metal in proportion to the applied voltage. Therefore, the resistance changes according
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to the voltage, that is, the metal does not satisfy Ohm’s law. In this talk, we will look closely at the meaning of Ohm’s law and share information on the principles and applications of nonohmic conductance.
T4-5 Topological materials (DCMMP) | Matériaux topologiques (DPMCM) / 2603
”Black holes, wormholes and solid state realizations of Sachdev- Ye-Kitaev models”
Author: Marcel Franz1
1 University of British Columbia
Corresponding Author: [email protected]
An intriguing connection, pointed out by Kitaev in 2015, exists between a simple model of Majorana fermions with random all-to-all interactions – the Sachdev-Ye-Kitaev (SYK) model – and the horizons of extremal black holes in two-dimensional anti-de Sitter space. This connection furnishes arare example of holographic duality between a solvable quantum-mechanical model and Einstein gravity. It also opens up a possibility to study quantum black holes and possibly also wormholes realized holographically in a quantum mechanical model, in a tabletop experiment. In this talk I will review some of these developments and describe the recent efforts to bring the family of SYK models closer to experimental reality. The proposed experimental realizations employ both complex and Majorana fermions in various atomic and solid state systems. These include some of the standard platforms for Majorana zero modes (proximitized quantum wires and topological insulator - superconductor interfaces) as well as electrons in the lowest Landau level in a graphene flake with an irregular boundary.
T4-1 Soft Matter PM-2 (DCMMP) | Matière molle PM-2 (DPMCM) / 2604
Machine Learning as a Tool to Study Soft Matter in Confinement
Author: Hendrick W. de Haan1
1 Ontario Institute of Technology
Corresponding Author: [email protected]
With the advent of robust nanoscale fabrication, the study of soft matter has become intertwined with nano- and microfluidic device design. Applications range from building nanoscale devices with which to isolate single biomolecules, to studying colloidal particles in nano- to microchannels. Modeling and simulation of soft matter have followed this shift and have become powerful tools both for characterizing the biological material and for aiding in the design of the devices. In such work, common tasks include solving electric fields in complicated geometries and extracting quantities of interest such as the mean first passage time of polymers or particles moving through the devices. Traditional approaches to solving these problem include mesh-based techniques such as the finite element method for electric fields, and particle simulations such as Langevin dynamics for the mean first passage time. In this talk, I will present work from my lab in which we use deep neuralnetworks to replace both of these traditional methods. The “slit-well” device will be used as an exemplar system. I will discuss the benefits of this machine learning approach, such as being mesh-free and parameterizable, as well as some of the remaining challenges.
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DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2605
29 - Shallow donor complexes in ZnO containing Sn and Li stud- ied by photoluminescence and density functional theory
Authors: Manu Hegde1; Abbas Nakhlband1; Simon Watkins1
Co-author: Lynn Boatner 1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected]
Abstract Lithium has been investigated in detail as a possible acceptor impurity in zinc oxide for many years. Li interstitials are highly mobile in ZnO under Zn rich conditions and diffuse easily at temperatures as low as 300C. In contrast Li substituting for Zn sites is a known deep acceptor and is formed at much lower concentrations under O-rich conditions. [1]. The high mobility of Li ions means that the formation of defect pairs between Li and various oppositely charged impurities should be easily formed. Defect pairs have been proposed as possible candidates for p-doping in ZnO as well as for quantum qubits, and therefore the subject is of general technological interest. In this work we study the low temperature photoluminescence (PL) of high quality ZnO single crystals grown by chemical vapor transport, and co-doped with Sn and Li. A well known donor bound exciton PL feature labeled I10 has recently been shown to include Sn substituting for Zn sites.[2] In this study we show that an additional constituent, likely substitutional Li is also involved. Annealing Sn-doped samples under oxygen poor conditions results in a complete suppression of I10, while diffusion of Li in air at ~700C results in a clear enhancement of I10. Density functional theory within the GGA+U approximation has been used to investigate the formation energy and defect transition energies of SnZn-LiZn nearest neighbour complexes in ZnO. These calculations indicate that the Sn-Li complex is indeed a shallow donor as expected on simple charge considerations. [1] K.E. Knutsen et al., J. Appl. Phys. 113, 023702 (2013) [2] J. Cullen et al., Appl. Phys. Lett. 102, 192110 (2013)
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2606
30 - Violation of Ohm‘s law in a Weyl metal
Author: Dongwoo Shin1
Co-author: Jeehoon Kim 2
1 POSTECH 2 Pohang University of Science and Technology
Corresponding Authors: [email protected], [email protected]
Weyl metal is one of the topological non-trivial materials holding Weyl fermions which are massless and have a chirality. The Weyl metal has been described in terms of axion electromagnetism rather than in Maxwell electromagnetism, and has peculiar properties such as chiral anomaly, the presence of magnetic monopole in the reciprocal lattice space and negative longitudinal magneto resistance. In this presentation, by transportation experiment besides negative longitudinal magneto resistance, we observed ohm’s law was broken in the Weyl metal and carried experimental and theoretical analysis of the violation of ohm‘s law [1].
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R2-6 Topological and 2D materials (graphene, etc) (DCMMP) | Matériaux topologiques et 2D (graphène, etc.) (DPMCM) / 2607
Emergent electronic states in chalcogenide/oxide heterostructures
Author: Ke Zou1
1 University of British Columbia
Corresponding Author: [email protected]
Realizing novel electronic states in two-dimensional chalcogenides, complex oxides, and their het- erostructures, which result from the reduced dimensionality and interfacial interactions with the nearby substrate, is of great interest from both fundamental and technological perspectives. Molec- ular beam epitaxy (MBE) is one of the most advanced synthesis techniques for the growth of materi- als with atomic-scale precision. AT UBC, we employ a dual-MBE system, capable of designing and synthesizing both types of materials and their heterostructures. Material systems showing emergent states will be presented in the talk. For example, enhanced superconductivity has been achieved in monolayer FeSe grown on SrTiO3 substrate. We determine the surface structure of SrTiO3 that is used to achieve superconducting FeSe films in experiments. The existence of a double TiO2 layer helps to transfer electrons to FeSe films, and leads to a band structure characteristic of superconduct- ing samples.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2608
3 - Upgrade of the electrostatic spectrometer and ion/shakeoff de- tectors in TRIUMF’s neutral atom trap apparatus.
Author: Alexandre Gorelov1
Co-authors: Melissa Anholm 2; James McNeil 3; John Behr 1; Dan Melconian 4; Gerald Gwinner 5
1 TRIUMF 2 University of Manitoba 3 University of British Columbia 4 Cyclotron Institute and Texas A&M University 5 U. Manitoba
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Measurements of correlation parameters from beta decay of atoms in a MOT may require application of an electric field, which can work as a spectrometer for recoiling ions and atomic shake-off electrons on their way to MCP based detectors in a back-to-back geometry. Such a field, in combination with the drift distance, separates in time the arrival of recoiling, differently charged ionized atoms on an ion detector relative to much faster moving shake-off electrons, detected by an electron MCP. This allows us to distinguish between ions with different charge and calculate correct kinematics event by event. In our earlier measurements of the beta asymmetry from beta decay of trapped polarized 37K atoms [B.Fenker et al. Phys. Rev. Lett. 120 062502 (2018)], we have achieved an electric field of about 540V/cm. Further increase of the field prevented simultaneous detection of ion and electrons, resulting inhigh, up to 1MHz, background count rate in both detectors. Recent development of spectrometer allowed us to reach a field strength of 1000V/cm and ensure
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reliable simultaneous operation of both ion and electron MCP based detectors in beta decay measurements of trapped 92Rb [J.McNeil, contributed talk to DNP-DPN].
M2-5 Nuclear Structure I (DNP) | Structure nucléaire I (DPN) / 2609
SPECTROSCOPY OF 98Ru
Author: S Valbuena1 Co-authors: P. E. Garrett 2; L Makhathini 3; R.A. Bark 4; V. Bildstein 5; T.R Rodriguez 6; S Triambak 6
1 university of Guelph 2 Department of Physics, University of Guelph, Guelph, Ontario 3 iThemba Labs, Old Faure Road, Faure, South Africa 4 Themba Labs, Old Faure Road, Faure, South Africa 5 Department of Physics, University of Guelph, Guelph, Ontario 6 Department of Physics and Astronomy, University of the Western Cape, Bellville, South Africa
Corresponding Author: [email protected]
A recent survey [1] of potential candidates for spherical vibrational motion [2] concluded that very few passed the criteria; of those that did, 98,100Ru were the most promising. However, in part this may have been due to the lack of detailed spectroscopic data for 98,100Ru. In order to remedy this, we have performed a high-statistics measurement of the β decay of 98,100Rh using the newly com- missioned β decay Tape Station at iThemba labs located near Cape Town, South Africa. Activities of 98,100Rh were produced using fusion evaporation reactions of 14N and 16O beams on an 89Y target, which was then transported from the irradiation station to a counting station. The counting station consisted of 4 clover-type high-purity germanium detectors, augmented by a TIGRESS detector, a plastic scintillator for the β particles, and an in-vacuum Si(Li) detector for conversion electrons. The decay of 98Rh and 100Rh to 98Ru and 100Ru was the first measurement to be completed on this new facility. Very high-statistics data sets were collected for 98,100Ru, resulting in considerable expan- sions of their decay schemes. In this presentation, we concentrate on the results for 98Ru from the analysis of the γ-γ coincidence matrix. A main focus of this work has been on possible states associated with the first excited 0+ state, + + + + + the 02 level. Several weak E2 transitions – the 495 keV (23 →02 ), 402-keV (23 →22 ) and 419-keV + + + (23 →41 ), were newly observed. The E2 transition to the 02 state possesses the largest relative + + B(E2) value, strongly suggesting that the 23 state is a band member of the excited 02 band. We have also observed a candidate level for the 4+ rotational band member, suggesting that 98Ru possesses a more-deformed excited 0+ band coexisting with a less-deformed ground state. Details of the analysis of the 98Rh decay to date will be given. [1] P.E. Garrett, J.L. Wood, and S.W. Yates, Phys. Scripta 93, 063001 (2018). [2] J. Kern et al., Nucl. Phys. A593, 21 (1995).
M2-5 Nuclear Structure I (DNP) | Structure nucléaire I (DPN) / 2610
Spectroscopic studies of the structure of neutron-rich isotopes 129Sn and 133Sn
Author: Fatima H. Garcia1 Co-authors: C. Andreoiu 2; Kevin Ortner ; Kurtis Raymond 1; K. Whitmore 3; Gordon Ball 4; Nikita Bernier 4; H. Bidaman 5; V. Bildstein 5; M. Bowry 6; David Cross ; I. Dillmann 6; Michelle Dunlop 7; Ryan Dunlop 7; A. B.
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Garnsworthy 6; P. E. Garrett 8; Greg Hackman 4; Jack Henderson 4; J. Measures 4; Dennis Muecher 7; B. Olaizola 6; Costel Petrache 9; Jason Park 10; Jennifer Pore ; Jenna Smith 4; Daniel Southall 4; C. E. Svensson 8; Marius Ticu 11; Joseph Turko 7; T. Zidar 5
1 Simon Fraser University 2 Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada 3 Department of Physics, Simon Fraser University, Burnaby, British Columbia 4 TRIUMF 5 Department of Physics, University of Guelph, Guelph, Ontario 6 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 7 University of Guelph 8 Department of Physics, University of Guelph, Guelph, Ontario 9 University Paris Sud 10 University of British Columbia/TRIUMF 11 Department of Chemistry, Simon Fraser University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
The study of radioactive isotopes is key to understanding the fundamental building blocks ofmat- ter. These investigations require state-of-the-art experimental stations, which exist only in select facilities around the world. The Gamma Ray Infrastructure For Fundamental Investigations ofNu- clei (GRIFFIN), at the ISAC facility of TRIUMF is a powerful decay spectrometer that can be used to study β decaying species. The tin isotopes are an important part of the nuclide chart duetotheir magic proton number, Z = 50, a stable configuration analogous to the noble gases. They spana total of forty isotopes, two neutron shell closures, at N = 50 (100Sn) and N = 82 (132Sn), and ex- tend up to N = 89 (139Sn), making them an important testing ground for nuclear structure theory. Furthermore they are important in the rapid neutron capture process (r-process), responsible for the production of the heaviest elements in our universe. An isotope of tin with 79 neutrons, 129Sn, was studied via the β decay of its indium parent, 129In, at the GRIFFIN station. So far the analysis of the decay spectroscopy data has uncovered twenty new transitions and seven new excited states, never before seen in this nucleus. The 133Sn nucleus was also studied at the GRIFFIN spectrometer, though the data was dominated by the βn decay of the 133In parent into 132Sn. Newly outfitted with BGO shields for Compton suppression, the GRIFFIN spectrometer has entered into a new phase; a reduction in the Compton continuum will allow for the observation of very weak transitions, offer- ing a more detailed look into the tin isotopes. Results from the study of 129Sn and 133Sn, detection mechanisms and potential implications will be discussed.
M2-5 Nuclear Structure I (DNP) | Structure nucléaire I (DPN) / 2611
Spectroscopic studies of 116,118,120Sn through thermal neutron in- duced reactions using FIPPS
Author: Kurtis Raymond1 Co-authors: Aimee Bell 2; Alain Astier 3; Amel Korichi 3; Andreas Zilges 4; Aurelien Blanc 5; Badamsambuu Jigmeddorj 6; Bingfeng Lv 7; Bo Cederwall 8; C. Andreoiu 9; Caterina Michelagnoli 10; Costel Petrache 11; Daphney Bucher 12; Erin Mcgee 13; Etienne Dupont 7; Fatima Garcia 2; Isaiah Djianto 2; Jakub Wisniewski 14; Jeffrey Vanhoy 15; Kenneth Whitmore 2; Kevin Ortner ; Mark Spieker 16; Paolo Mutti 10; Paul Garrett 13; Radomira Lozeva 3; Sally Valbuena 6; Sarah Prill 17; Steven Yates 18; Ulli Koester 10; Waldemar Urban 14; Yung Hee Kim 10
1 SFU 2 Simon Fraser University 3 Cnrs Csnsm In2p3 Orsay 4 Inst. Physics - Univ Cologne
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5 Cea Bruyeres Le Chatel 6 University Of Guelph 7 Cnrs Csnsm Spectro Nucl De Masse Orsay 8 Phys Dept Royal Institute Of Technology Stockholm 9 Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada 10 ILL 11 University Paris Sud 12 Ithemba Labs Faure 13 Dept Physics University Of Guelph 14 University Of Warsaw, Faculty Of Physics 15 United States Naval Academy Annapolis 16 Sans Employeur Grenoble 17 University Of Cologne 18 University Of Kentucky
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], petra- [email protected], [email protected]
Studies of tin isotopes are important for understanding the structure of singly-closed shell nuclei. The 116,118,120Sn isotopes are examples of even-even singly-closed shell nuclei close to the line of stability. Using (nth, γ) reactions provides a comprehensive study of the level scheme of a nucleus. Despite many previous studies for stable tin isotopes, many nuclear levels are missing spin and parity assignments. Experiments involving 116,118,120Sn were conducted in 2018 at ILL, Grenoble, using FIPPS (FIssion Product Prompt γ-ray Spectrometer), which uses eight highly efficient, clovered, n-type, HPGe detectors to measure low intensity gamma rays. This aids in identify previously un- known transition multipolarities, and thus, provide the spin states of ambiguous energy levels. % 116 work on this In the study of Sn, sixteen ancillary LaBr3 detectors were used in the experiment to provide ps timing measurements to deduce state lifetimes. The experiments involving 118,120Sn fea- tured eight additional HPGe clovers, from IFIN-HH (Horia Hulubei National Institute of Physics and Nuclear Engineering), to further improve the array’s efficiency. The high number of statistics that FIPPS provides aids in making polarization measurements and angular correlation measurements to identify the spin states of energy levels without definite properties. Study of the electromagnetic character of weak transitions in tin will establish the parity of the de-excited states, help complete the understanding of singly-closed shell nuclei, and nuclear structure as a whole. The current work being done to study the tin species will be presented.
T2-2 Plasmas at Surfaces (DPP) | Plasmas sur des surfaces (DPP) / 2612
Negative-ion surface production in hydrogen low-pressure plas- mas
Authors: Gilles CARTRY1; Lenny TAHRI1; Jean-Marc LAYET2; Alain SIMONIN3
1 Aix Marseille Université 2 Aix Marseille University 3 IRFM, CEA
Corresponding Authors: [email protected], [email protected], [email protected], lenny.tahri@univ- amu.fr
Negative-ions (NI) may play an important role on discharge kinetics in low-pressure low-temperature plasmas, especially when using electronegative gases. NI are usually formed by dissociative elec- tron attachment on molecules, and trapped inside the plasma volume due to the positive potential difference between plasma and surfaces. In certain circumstances, negative-ions are also formed on surfaces upon impact of neutral particles and capture of an electron to the material, or impact of positive ions (PI) and capture of two electrons by the incident particle. These negative-ions are
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then accelerated back towards the plasma by the sheath and may deposit some energy in the plasma volume. Low work function materials in interaction with plasmas are efficient for NI surface produc- tion due to the low energy required to extract an electron from the solid. However, other electronic property of materials, such as the presence of a band-gap or a negative electron affinity, may play an important role in electron capture as demonstrated in beam experiments. In this contribution we quantify and study hydrogen negative-ion surface production on various materials with a strong emphasis on carbon surfaces. Samples of different kinds are installed on a sample holder in the diffusion chamber of a low-pressure capacitively or inductively coupled plasma, facing whether a mass spectrometer (MS) or a magne- tised retarding field energy analyser (MRFEA). The sample is negatively DC biased and NIformed upon PI impact are accelerated towards the plasma. Considering the low pressure used in this study, they cross the plasma without any collision and are collected by the MS which provides a mass and energy analysis, or by the MRFEA which gives the NI current. A pulsed DC biased method has been developed to study NI surface production on insulating materials. Details on experimental methods and modelling will be given. Basic production mechanisms will be detailed. It will be shown that electronic properties of materials, and not only its work function, can play a role on surface ionization efficiency in plasma.
T4-10 Thinking Outside the Box (DPE) | Penser hors de la boîte (DEP) / 2613
On developing an open access first year physics textbook and other free things
Author: Ryan Martin1
1 Queen’s University
Corresponding Author: [email protected]
In this talk, I will review my experience working with students at Queen’s University to develop an open access textbook aimed at introductory calculus-based physics. In particular, I will discuss how we worked towards designing a text that is better adapted for the flipped classroom approach than current offerings, and how we managed the process of developing the text. While experimental physics is arguably half of the discipline, introductory textbooks tend to ignore this aspect of skill development completely; I will also discuss how we have incorporated a curriculum in experimental physics within the textbook and report on our preliminary experience using this new textbook dur- ing the last academic year. Finally, I will briefly report on two additional open source projects that we developed with our students in order to: (1) provide a free in-class response system in support of active learning, and (2) support the development of computer literacy in the labs.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2614
92 - PICO-40l Installation and Commissioning
Author: Tristan Sullivan1
1 Queen’s University
Corresponding Author: [email protected]
The PICO experiment is a dark matter direct-detection experiment at SNOLAB, which has set world-leading limits on the spin-dependent couplings of WIMPs to nucleii in the mass range of approximately 10- 100 GeV. There have been several iterations of the PICO detector; each is a bubble chamber with a super-heated fluid as the active ma-
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terial. The current version of the PICO detector is PICO-40l, which has been substantially redesigned since the previous verison, PICO- 60. The installation of PICO-40l underground will be completed in early 2019, with commissioning and calibration data-taking occurring in the spring and summer. The primary purpose of PICO-40l is to demonstrate the feasibility of the new design, which will be implemented at ton scale by the next detector, PICO-500. The commissioning results will be presented, along with any implications for the design of PICO-500. The schedule for data-taking will be presented as well, and the expected dark matter limits to be obtained from this run.
T2-7 Nobel Prize Session (DAMOPC) | Session de prix Nobel (DPAMPC) / 2615
Laser Wakefield Driven X‐ray Sources in Canada: Future perspec- tives for non-destructive imaging and Global Food Security
Authors: Jean Claude Kieffer1; Emil Hallin2
1 INRS 2 University of Saskatchewan
Corresponding Authors: [email protected], [email protected]
Very intense hard X-ray beams (1.5µm X-ray source size, 5µJ-50µJ/shot in the 30keV-40keV band, 50mrad x 50mrad divergence, critical energy for the X-ray spectrum of 30keV) have been generated through ultra-relativistic self-guiding over long gas jet length (cm range). I will describe the exper- iments realized with our new laser facility (delivering up to 7J in 18fs at 2.5Hz on target) and I will discuss the empirical scaling laws we have obtained correlating the X-ray photon number to the laser and gas jet parameters. Our scaling indicates that a 40keV X-ray beam with energy of 1mJ range per shot can be produced with a driving laser with power in the 1 – 2PW range. The X-ray source has been operated at the nominal 2.5Hz repetition rate giving an average powerin the 12µW-125µW range in the 30keV-40keV spectral band. High throughput X-ray phase contrast imaging and 3D phase contrast tomography of various objects have been realized. We demonstrated that the phase contrast imaging was giving the possibility to see transparent very small objects (10µm to 300µm diameter range) embedded inside inhomogeneous and anisotropic thick (absorbing) environment. We will present the experimental demonstration and discuss the potential for non- destructive imaging. There is a need for a stand-alone system dedicated for plants and seeds screening available onpro- duction sites. I will present our funded program in Canada in developing high throughput X-ray phase contrast plant imaging and screening using LWFA-based X-ray sources (10keV-100keV). This effort is realized through an initiative led by the Global Institute for Food Security (GIFS) attheUof Saskatchewan that aims to establish the correlation between the phenotypic expression of a plant and its adaptation to biotic and abiotic environmental stress.
M1-9 Soft Condensed Matter I (DCMMP) | Matière condensée molle I(DPMCM) / 2616
Tilting Transition in a Liquid Crystalline Polymer Brush
Authors: Steven Blaber1; Nasser Abukhdeir1; Mark MatsenNone
1 University of Waterloo
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Corresponding Authors: [email protected], [email protected], [email protected]
The equilibrium phase behaviour of a semi-dilute, liquid crystalline (LC) polymer brush isinvesti- gated, using self-consistent field theory with wormlike chains and implicit solvent. For good solvent conditions, the isotropic interactions favor a stretched brush while the anisotropic LC interactions favor collapsing into a high-density nematic state. By allowing the nematic director to orient freely, we find that the polymers collapse by tilting rather than backfolding as previously thought. Within the implicit solvent model the transition to a tilted state is an instability; however, the transition becomes continuous once the semi-dilute approximation is relaxed.
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2617
Using the profile-likelihood method to search for dark matter in DEAP-3600
Author: Ashlea Kemp1
1 Royal Holloway, University of London
Corresponding Author: [email protected]
The DEAP-3600 detector based 2km underground at SNOLAB (Sudbury, Canada) is a dark matterdi- rect detection experiment. The detector consists of a single-phase liquid argon (LAr) target, of3279 kg mass. Currently, there have been two WIMP dark matter searches performed by the DEAP-3600 collaboration; for both results, a cut-and-count approach was employed. In this talk, the develop- ment of a profile-likelihood ratio statistical test and its application to DEAP-3600 will be presented. This test allows the WIMP search to account for the expected distribution of WIMPs and backgrounds in a multi-dimensional parameter space, and thereby perform a more sensitive search. Furthermore, we will also show how the profile-likelihood approach can be used to search for hidden photons and axion-like particles in the DEAP-3600 detector. We will discuss the expected signature from such particles, and how this approach can be used to search for them over the naturally present backgrounds.
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2618
18 - Improvement of the Efficiency and Beam Quality of theTRI- UMF Charge State Booster
Author: Joseph Adegun1
Co-authors: Friedhelm Ames 1; Oliver Kester 1
1 TRIUMF
Corresponding Authors: [email protected], [email protected], [email protected]
At TRIUMF charge breeding of rare isotopes is based on an Electron Cyclotron Resonance Ion Source (ECRIS). A modified 14.5 GHz PHOENIX booster from Pantechnik is being used to boost thecharge of rare isotopes after production from the sophisticated TRIUMF target stations in order to match the acceptance velocity of the TRIUMF LINAC. To improve the efficiency of the breeder, a two-frequency heating and frequency tuning technique of the source plasma will be implemented, and the improve- ment of the beam quality (emittance) will be investigated by simulating the extraction system of the breeder to explore the systematics of beam emittance versus plasma and extraction parameters and subsequent measurements. Quadrupole scan technique method will be used to measure the emittance of the breeder.
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PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2619
72 - Scintillating Bubble Chamber for Detecting Dark Matter
Author: Hector Hawley HerreraNone
Corresponding Author: [email protected]
The search for dark matter is evolving, and the quest to reach lower cross-sections leadstonew technologies. One of the newer proposals involves the use of a bubble chamber which employs noble elements (such as argon and xenon) as the active mass. The switch to these targets opens the possibility for a much lower sensitivity to backgrounds as well as an additional scintillation channel for use in discrimination which opens up the potential for lower mass dark matter to be studied with a lower energy threshold. This talk will introduce the scintillating bubble chamber as well asreport on the progress and timeline.
M2-8 General Relativity I (DTP) | Relativité générale I (DPT) / 2620
Lost horizons: modelling the formation and evaporation of non- singular black holes.
Author: Gabor Kunstatter1
1 University of Winnipeg
Corresponding Author: [email protected]
Thanks to recent gravitational wave observations, we have evidence for the validity of Einstein’s theory in the strong field region, including near black hole event horizons. The existence ofblack holes gives rise to theoretical issues, such as the necessary existence of singularities and the related information loss conundrum, that will hopefully be resolved by quantum mechanics. In the absence of a complete testable theory of quantum gravity, it is useful to study simplified models that hopefully retain essential, relevant features of the full theory. After a brief introduction to the subject, Iwill describe recent work on a class of such models that designed to describe the quantum dynamics of singularity free spherical black hole formation and evaporation.
R1-3 Condensed Matter Theory II (DCMMP) | Théorie de la matière condensée II (DPMCM) / 2621
Symmetry protected Luttinger liquids on the surface of Quantum Hall Nematics.
Author: Kartiek Agarwal1
1 McGill University
Corresponding Author: [email protected]
Quantum Hall Ferromagnets are a unique platform to study the confluence of symmetry-broken order parameter and topological physics. Recent experiments by Feldman et al.[1] observe clear signatures of valley-polarized Quantum Hall Ferromagnets on the surface of Bi(111) in the presence of strong magnetic fields. The tunneling conductance shows a discrete spectrum indicating thefor- mation of Landau levels while individual nematic Landau level orbits pinned to impurities indicate selective occupation of certain valleys. Further recent experiments[2] observe domain wall states
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between such nematic domains. Curiously, these domain walls appear to host low energy excita- tions that appear to be gapped/gapless depending on the filling fraction of the nematic quantum Hall states. We explain[3] these observations both qualitatively and quantitatively by highlighting the role of interactions and symmetries in engendering such exotic Luttinger liquids. [1] B. Feldman et al., Science 2016 [2] M. T. Randeria, KA et al., Nature 2019 [3] KA et al., ArXiv:1807.10293
R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2622
Precise Measurement of Rare Pion Decay
Author: Tristan Sullivan1
1 Queen’s University
Corresponding Author: [email protected]
The rare decay of the pion, to an electron and a neutrino, isan important process in the Standard Model. The branching ratio of this decay is one of the most precisely calculated weak interaction observ- ables involving quarks. Measurement of the branching ratio provides a sensitive test of lepton universality and tight constraints on many new physics scenarios with mass reach up to 1000 TeV. The PIENU experiment at TRIUMF aims to measure the branching ratio to a precision of less than 0.1%. The status of the analysis, and prospects for achieving the precision goal, will be presented. A secondary re- sult, placing limits on the mixing of the muon neutrino with a heavy neutrino, will be presented as well.
T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2623
The nuclear structure of 118Sn studied through the β-decay of 118In at TRIUMF
Author: Kevin OrtnerNone
Co-authors: A. B. Garnsworthy 1; B. Olaizola 1; C. Andreoiu 2; C. E. Svensson 3; Costel Petrache 4; Daniel Southall 5; David Cross ; Dennis Muecher 6; Fatima H Garcia 2; Gordon Ball 5; Greg Hackman 5; Harris Bidaman 6; Iris Dillmann 7; J. Measures 5; Jack Henderson 5; Jason Park 8; Jenna Smith 5; Jennifer Pore ; Joseph Turko 6; Kenneth Whitmore 2; Kurtis Raymond 2; M. Bowry 1; Marius Ticu 9; Michelle Dunlop 6; Nikita Bernier 5; P. E. Garrett 3; Ryan Dunlop 6; Tammy Zidar 6; V. Bildstein 6
1 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 2 Simon Fraser University 3 Department of Physics, University of Guelph, Guelph, Ontario 4 University Paris Sud 5 TRIUMF 6 University of Guelph 7 Universität Basel 8 University of British Columbia/TRIUMF 9 Department of Chemistry, Simon Fraser University
Page 118 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], fatimagar- [email protected], [email protected], [email protected], [email protected], [email protected], vbild- [email protected], [email protected]
The isotopes of tin are of great interest to the study of nuclear shell evolution, as they spanfrom doubly magic 100Sn to 132Sn and beyond. Due to the highly stable closed shell of fifty protons, the even-even tin isotopes mid-shell between N = 50 and N = 82 are known to be spherical in their ground state. However, low-lying deformed states due to 2p-2h excitations across the closed proton shell are also observed and it is important to determine the degree of mixing between the deformed states and the “normal” states for theoretical models. The 2p-2h rotational band built on an excited 0+ state has been observed in many studies on 118Sn. New measurements to further characterize this rotational band in 118Sn have been made using the Gamma Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) at the TRIUMF-ISAC facility. GRIFFIN’s powerful array of six- teen HPGe clover detectors provides excellent energy resolution and efficiency for identifying and separating low intensity gamma rays, and can be used in coincidence mode to place newly observed transitions. Discrepancies between two studies on the intensities of a ≈285~keV triplet have been identified using γ-γ coincidence measurements. Most notably, the branching ratio of a 284.6~keV transition within the intruder band was measured to be half of the previously reported value, leading + → + to a change in its B(E2; 22 02 ) value from 39(7) W.u. to 18(3) W.u.. Further to these findings, forty four newly observed transitions and one new energy level have been placed in the level scheme and will be discussed.
T2-4 Indirect and collider searches for dark matter (PPD) | Recherches indirectes et par colli- sionneurs pour la matière sombre (PPD) / 2624
Search for Dark Matter with NEWS-G experiment
Author: Marie-Cécile Piro1
1 University of Alberta
Corresponding Author: [email protected]
The NEWS-G direct dark matter search experiment is using spherical proportional counters (SPCs) with light noble gases as Ne, He, H to explore very low mass WIMPs parameter space. First results obtained with a SPC prototype operated with Ne gas at the Laboratoire Souterrain de Modane (LSM) have already placed NEWS-G as a leader in the search for low-mass WIMPs. Recent and planned improvements for the next phase of the experiment will be presented including the reduction of the background levels, detector performances and stability, and detector characterization. The next generation detector will consist of a larger volume 140 cm diameter SPC to be operated at SNOLAB with H and He gas. The use of lighter targets, improved thresholds and detector performance and with a significant reduction of the background levels will allow for unprecedented sensitivity to sub-GeV WIMPs down to 0.1 GeV. The current and future stages of the NEWS-G experiment inthe context of the global dark matter search will also be discussed.
W2-2 Quantum Information (DAMOPC/DTP) | Information quantique (DPAMPC/DPT) / 2625
Investigation of radiation damage centers in highly isotopically enriched silicon-28 as potential single spin qubits accessible via spin/photon coupling
Author: Mike Thewalt1
1 Department of Physics, SFU
Page 119 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
The remarkable optical properties of highly isotopically enriched silicon-28, resulting from the near- elimination of inhomogeneous broadening mechanisms, has led to the optical control and measure- ment of the electronic and nuclear spins of ensembles of shallow donor impurities, resulting in some record solid state coherence times. [1.2] These optical transition unfortunately have too low a dipole moment and emission efficiency to allow for single spin readout using cavity QED. A different, deep donor, transition has been proposed for enabling a cavity QED based spin/photon platform using integrated silicon photonics, but it has the disadvantage of operating at the rather difficult wave- length of 2.9 microns. [3] Our recent discovery that well-known silicon radiation damage centers have remarkably narrow linewidths in silicon-28 [4] led us to investigate these centers as possible spin qubits. Some of these centers have the advantage of optical transitions in the 1.3 to 1.6 micron telecom bands. I will describe our recent unpublished results for one center which has long electron and nuclear spin coherence times, good emission efficiency, and an oscillator strength which should allow spin/photon coupling using cavity QED in an integrated silicon photonics platform. [1] M. Steger, K. Saeedi, M.L.W. Thewalt, J.J.L. Morton, H. Riemann, N.V. Abrosimov, P. Becker, H-J. Pohl, Quantum information storage for over 180 s using donor spins in a 28Si “semiconductor vac- uum”. Science 336, 1280–1283 (2012). [2] K. Saeedi, S. Simmons, J. Z. Salvail, P. Dluhy, H. Riemann, N. V. Abrosimov, P. Becker, H.-J. Pohl, J. J. L. Morton, M. L. W. Thewalt, Room-temperature quantum bit storage exceeding 39 minutes us- ing ionized donors in silicon-28. Science 342, 830–833 (2013). [3] K. J. Morse, R. J. S. Abraham, A. DeAbreu, C. Bowness, T. S. Richards, H. Riemann, N. V. Abrosi- mov, P. Becker, H.-J. Pohl, M. L. W. Thewalt, and S. Simmons. A photonic platform for donor spin qubits in silicon. Science Advances, 3(7), 2017. [4] C. Chartrand, L. Bergeron, K. J. Morse, H. Riemann, N. V. Abrosimov, P. Becker, H.-J. Pohl, S. Simmons, M. L. W. Thewalt, Highly enriched 28Si reveals remarkable optical linewidths andfine structure for well-known damage centers. Phys. Rev. B 98, 195201 (2018).
M1-5 Nuclear Astrophysics (DNP) | Astrophysique nucléaire (DPN) / 2626
Evolution of the N=82 Neutron-Deficient Shell Closure and Push- ing Toward the Proton Drip-Line at TITAN
Author: Brian KootteNone
Co-authors: C. Andreiou 1; Soenke Beck 2; Thomas Brunner 3; Jens Dilling 4; Iris Dillmann ; ELEANOR DUNLING 5; Jake Flowerdew 6; Leigh Graham 5; Gerald Gwinner 7; A. Jacobs 5; Renee Klawitter 8; Yang Lan 5; Erich Leis- tenschneider 5; M. Lykiardopoulou 5; Victor Monier 9; Ish Mukul 5; Stefan Paul 5; Moritz Pascal Reiter 10; Robert Thompson 11; J.L. Tracy, Jr. 5; Mike Vansteenkiste 12; Michael Wieser 6; Christian Will 13; Anna Kwiatkowski 5
1 Department of Physics, Simon Fraser University, Burnaby, British Columbia 2 University of Giessen/GSI 3 McGill University 4 triumf/UBC 5 TRIUMF 6 University of Calgary 7 University of Manitoba 8 Max-Planck-Institut fur Kernphysik, Heidelberg D-69117, Germany 9 University of York 10 University of Giessen/TRIUMF 11 University of Calgary, Canada 12 Waterloo/TRIUMF 13 University of Giessen
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Corresponding Authors: [email protected], [email protected], [email protected], sea- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
In the region where the expected N=82 shell closure approaches the proton drip-line, we are con- fronted with our poor knowledge of the nuclear binding energies. Precision experimental data is critical if we are to gain an understanding of how this neutron shell evolves for the heaviest N=82 isotones. The binding energies of neutron deficient nuclei can also reveal the exact location ofthe proton drip-line. However, the current lack of precision mass measurements in this region makes these nuclei stand out as a clear target for mass spectrometry studies, which allow for the determina- tion of these binding energies. Furthermore, masses in this region can provide an anchor for chains of alpha decays whose origins extend up to A≈170, and for which only relative masses are presently known. The Isotope Separator and ACcelerator (ISAC) facility at TRIUMF produces intense beams of exotic isotopes for nuclear science. I will present the results of a series of atomic mass measurements of neutron-deficient Yb and Tm isotopes around the N=82 shell closure. Several of thesemasses were measured directly for the first time. These measurements were carried out using the recently commissioned Multiple Reflection Time-Of-Flight Mass Spectrometer (MR-TOF-MS) at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN). The results enable us to reduce the uncertainty in the nuclear binding energies, thus pushing towards the proton drip-line and providing new insight into the behaviour of the N=82 shell closure far from stability.
W-PLEN1 Plenary Session | Session plénière - Michael Thewalt, SFU / 2627
How is silicon-28 a ”semiconductor vacuum”? / « Comment le silicium 28 est-il un « vide semi-conducteur ? »
Author: Mike Thewalt1
1 Department of Physics, SFU
Corresponding Author: [email protected]
I will begin with a brief introduction to optical spectroscopy in semiconductors, emphasizing the analogy between impurities and excitations in semiconductors to aspects of atomic and particle physics. In this analogy, each semiconductor is a special vacuum in which the band gap energy is equivalent to the energy threshold for the production of an electron-positron pair in the real vacuum. The electron-hole pair created by the absorption of above band gap light are of course differentin that the electron and hole can have different effective masses, but we can still think of themas antiparticles which can annihilate with the emission of a photon of light. However, all common semiconductors, including silicon upon which much of our computing, com- munication and entertainment technologies are based, differ from the real vacuum in that the ener- gies of all excitations, and therefore the linewidths of all optical transitions, have as a limiting factor various inhomogeneous broadening mechanisms such as local electric and strain fields. Our discov- ery in 2001 that the linewidths of optical transitions in high-quality natural silicon was limited by inhomogeneous broadening due to the random placement of the three stable isotopes of silicon in the crystal lattice, and that inhomogeneous broadening could be essentially eliminated by the removal of silicon-29 and silicon-30, leaving only silicon-28, led to the coining of the phrase “semiconductor vacuum”. The availability of highly isotopically enriched silicon-28 has since led to a series ofnew discoveries, some of which overturned long-standing “facts” about defects in silicon. It also led to the realization that in silicon-28, some optical transitions, which were over 100 times sharper than in the best natural silicon, could be used to optically measure and prepare electronic and nuclear spins. These spins were already recognized as some of the most promising quantum bits, or qubits, on which to base future quantum computing and communications technologies. It
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further led to new ideas for single spin qubits in silicon that could by prepared and measured using spin/photon conversion involving cavity quantum electrodynamics, ideas which are being actively pursued at this time.
Je commencerai par une brève introduction à la spectroscopie optique dans les semi-conducteurs, mettant l’accent sur l’analogie entre impuretés et excitations dans ceux-ci et les aspects de laphysique atomique et corpusculaire. Dans cette analogie, tout semi-conducteur est un vide spécial dans lequel l’énergie de bande interdite est équivalente au seuil d’énergie pour la production d’une paire électron- positron dans le vide réel. La paire électron-trou créée par l’absorption de la lumière de bande in- terdite ci-dessus est bien sûr différente du fait que l’électron et le trou peuvent avoir des masses effectives différentes, mais nous pouvons encore les entrevoir à titre d’antiparticules qui peuvent annihiler l’émission d’un photon de lumière. Cependant, tous les semi-conducteurs communs, y compris le silicium sur lequel se fonde une bonne partie de nos technologies de calcul, de communication et de divertissement, difèrent du vide réel du fait que les énergies de toutes les excitations, et donc les largeurs de ligne de toutes les transitions op- tiques, ont divers mécanismes de mobilité non-homogène à titre de facteur limitatif, tels les champs locaux électriques et de contraintes. Notre découverte en 2001 de la limitation des largeurs de ligne des transitions optiques dans le silicium naturel de haute qualité, par une mobilité non-homogène en raison du placement aléatoire des trois isotopes de silicium stables dans le réseau cristallin, et du fait qu’une mobilité non-homogène pouvait essentiellement être éliminée en enlevant le silicium-29 et le silicium-30, laissant uniquement le silicium-28, a donné naissance au terme « vide semi-conducteur ». L’existence du silicium-28 hautement enrichi sur le plan isotopique a depuis amené une série de nouvelles découvertes dont quelques-unes ont renversé des « faits » de longue date sur les défauts du silicium. Cela a aussi permis de se rendre compte que, dans le silicium-28, certaines transitions optiques, au- delà de 100 fois plus aiguës que le meilleur silicium naturel, pouvaient servir à mesurer optiquement et à préparer des spins électroniques et nucléaires. Ces spins étaient déjà reconnus comme bits quan- tiques, ou qubits, parmi les plus prometteurs, sur lesquels fonder les futures technologies quantiques de calcul et de communication. Cela a aussi suscité de nouvelles idées sur les qubits à spin unique dans le silicium qui pourraient être préparés et mesurés par la conversion spin/photon, employant l’électrodynamique quantique en cavité, idées que l’on poursuit activement aujourd’hui.
W2-8 Nuclear Astrophysics II (DNP) | Astrophysique nucléaire II (DPN) / 2628
Masses of neutron-rich Ga isotopes for the formation of the 1st r-process abundance peak in neutron star merger
Author: Moritz Pascal Reiter1 Co-authors: Andree Sieverding 2; Anna Kwiatkowski 3; Brian Kootte ; C. Andreoiu 4; C. SCHEIDENBERGER 5; Christine Hornung 6; D Welch 7; ELEANOR DUNLING 3; Erich Leistenschneider 3; Gabriel Martínez Pinedo 8; Gerald Gwinner 9; Hendrik Schatz 10; Iris Dillmann ; Jens Dilling 11; Jonas Lippuner 12; Luke Roberts 7; Michael Wieser 13; Robert Thompson 14; Samuel Ayet San Andres 6; Stefan Paul 3; Stylianos Nikas 2; Thomas Brunner 15; Timo Dickel 16; Wolfgang Plass 6; Yang Lan 3
1 JLU, TRIUMF 2 GSI, TU-Darmstadt 3 TRIUMF 4 Simon Fraser University 5 GSI Helmholtzzentrum fu ̈r Schwerionenforschung, D-64291 Darmstadt, Germany 6 GSI, JLU-Giessen 7 NSCL 8 GSI Darmstadt 9 University of Manitoba
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10 National Superconducting Cyclotron Laboratory 11 triumf/UBC 12 Los Alamos National Lab, JINA 13 University of Calgary 14 University of Calgary, Canada 15 McGill University 16 GSI
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Since the discovery of the GW170817 binary neutron star merger and the associated kilonova, it be- came clear that such an event can indeed produce heavy elements up to the lanthanide region and re- cent work has been focussed on understanding the formation of the 2nd and 3rd r-process abundance peaks as well as the lanthanide region. However nuclear data in these regions is scares. The situation is advantages for the 1st abundance peak, which is more in reach of current radioactive beam (RIB) facilities. However beams of these neutron-rich isotopes around the closed neutron shell at N=50 suffer from strong isobaric background, making high precision measurements challenging. Toover- come the strong background an isobar separator based on the Multiple-Reflection Time-Of-Flight Mass Spectrometry (MR-TOF-MS) technique has been installed at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN), similar to other ion trap on-line facilities. The MR-TOF-MS enables high precision mass measurements of very short-lived nuclides that are weakly produced. With mass measurements of neutron-rich Ga isotopes at TITAN, we determine one of the last missing experimental properties to model the formation of the A=84 abundance maximum of the 1st r-process peak under conditions prevalent in the ejecta of the blue kilonova of the GW170817 binary neutron star merger. Performing large-scale nuclear reaction calculations with two state of the art reaction codes, we can perform a detailed investigation on how the abundance maxima at A=80 and A=84 of the 1st r-process abundance peak are formed. This indicates that binary neutron star mergers may not have the potential to be the dominant source of light r-process elements.
W2-7 Condensed Matter Theory I (DCMMP) | Théorie de la matière condensée I(DPMCM) / 2629
Charge and spin-specific local integrals of motion in a disordered Hubbard model
Authors: Rachel Wortis1; Branden Leipner-Johns1
1 Trent University
Corresponding Author: [email protected]
While many-body localization has primarily been studied in systems with a single local degree of freedom, experimental studies of many-body localization in cold atom systems motivate exploration of the disordered Hubbard model. With two coupled local degrees of freedom it is natural to ask how localization in charge relates to disorder in spin and vice versa. Most prior work has addressed disorder in only one of these sectors and often has not used measures of localization which distin- guish between charge and spin. Here we explore localization in the Hubbard model with a wide range of independent values of charge and spin disorder, using measures of localization based on charge and spin-specific integrals of motion. Our results show a symmetry between the response of the charge to spin disorder and vice versa, and we find very weak disorder in one channel, so long as the disorder in the other channel is sufficiently strong, results in localization in both channels. Further, the weaker the disorder in the less-disordered channel, the longer the time scale at which localization appears in the dynamics of this degree of freedom.
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W1-5 ”Bertram Brockhouse and the History of Canadian Neutron Scattering” (DHP) | ”Bertram Brockhouse et l’histoire de la diffusion de neutrons canadienne” (DHP) / 2630
Impact of the Canadian Neutron Beam Centre
Authors: Daniel Banks1; Thad Harroun2
1 NRC 2 Brock University
Corresponding Authors: [email protected], [email protected]
The March 31, 2018 closure of the National Research Universal reactor marked the endofover70 years of materials research using neutron beams at the Chalk River Laboratories in Chalk River, Ontario. This closure will have a major impact on the Canadian materials research community, in- cluding researchers in the physics, chemistry, and engineering of materials. We examine the impacts that have arisen from this history in form of benefits to the user community, for example: enhanc- ing scientific excellence (including evidence from bibliometric data, benchmarked against foreign neutron beam facilities), fostering its growth (introducing a community size metric based on papers that use neutron scattering in Canada), boosting university-industry collaborations and training highly qualified people (based on a longitudinal analysis of academic and career paths of thestudent researchers who used the CNBC from 1984 to 2018).
T4-10 Thinking Outside the Box (DPE) | Penser hors de la boîte (DEP) / 2631
ComPAIR: A Flexible Teaching Technology for Facilitating Peer Evaluation
Authors: James Charbonneau1; Tiffany Potter2; Letitia Englund2; Pan Luo2
1 University of British Columbia 2 UBC
Corresponding Author: [email protected]
We introduce ComPAIR, an open source, peer feedback and teaching technology developed at UBC that provides students a safe, flexible environment to develop the skill of evaluating another person’s work, and in turn, receive evaluations from their peers. We highlight its usage in a 300 level physics class. The effectiveness of peer feedback can be limited by the relative newness of students to boththe course content and the skills involved in providing good feedback. ComPAIR makes use of students’ inherent ability and desire to compare: according to the psychological principle of comparative judgement, novices are much better at choosing the “better” of two answers than they are atgiving those answers an absolute score. By scaffolding peer feedback through comparisons, ComPAIR provides an engaging, simple, and safe environment that supports two distinct outcomes: 1) students learn how to assess their own work and that of others in a way that 2) facilitates the learning of subtle aspects of course content through the act of comparing. To explore ComPAIR check out our sandbox site: https://compairdemo.ctlt.ubc.ca/ Details on how to set up ComPAIR at your own institution can be found here: https://lthub.ubc.ca/guides/compair/
M2-1 Interaction Between Matter and Light (DAMOPC) | Interaction de la matière et de la lumière (DPAMPC) / 2632
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Epitaxial Growth of Single Crystal Noble Metals for Plasmonic and Nanophotonic Applications
Author: Sasan V. Grayli1 Co-authors: Gary Leach 1; Finlay MacNab 1; Xin Zhang 2; Saeid Kamal 3
1 Simon Fraser University 2 4DLABS 3 LASIR
Corresponding Authors: [email protected], [email protected]
Material quality and crystallinity play an important role in the activity of plasmonic devices. Plas- monic structures made from monocrystalline metals may be expected to display much higher effi- ciency and stability than polycrystalline devices which are subject to many losses due to the presence of grain boundaries and defects. With the help of a novel epitaxial electroless deposition (EED) chem- istry, ultrasmooth gold films can be grown on monocrystalline silver surfaces. In this approach, the electrochemical incompatibility of gold and silver can be overcome in concentrated sodium hydrox- ide (NaOH) (1 M) where the presence of OH⁻ causes a decrease in the reduction potential of gold cations by forming Au(OH)₄⁻complexes (E≈0.55 V), an increase in the oxidation potential of the silver electrode (E≈1.45 V), and acts as a reducing agent. As a result, ultrasmooth monocrystalline gold films are grown with the same crystalline orientation as the underlying silver film. Thischemistry enables the growth of gold from a few monolayers up to few hundreds of nanometers uniformly over a large area. Furthermore, this approach enables the fabrication of large area metasurfaces made of gold and silver epitaxially grown nanostructures that can be used in a variety of different applications. The growth of gold films and nanostructures can also be manipulated by the introduc- tion of anionic species during the deposition, and leads to the formation of surface nanostructures with specific shape, due to preferential interaction of the anions with certain facets of thegrowing crystalline structures.
T3-7 Frontiers in optics (DAMOPC) | Frontières en optique (DPAMPC) / 2633
Current dissipation of ultracold atoms in an optical lattice
Authors: Rhys Anderson1; Fudong Wang2; Vijin Venu1; Peihang Xu1; Stefan Trotzky1; Frederic Chevy3; Joseph Thywissen1
1 University of Toronto 2 South University of Science and Technology 3 Laboratoire Kastler Brossel, Ecole Normale Superieure
Corresponding Author: [email protected]
We measure the current dissipation rate of fermionic ultracold atoms in an optical lattice. A quantum gas microscope enables high-resolution fluorescence imaging of atoms pinned to lattice sites. Using micron-scale periodic displacements of an underlying harmonic potential to provide an oscillating uniform force, we measure the global current response of the atoms for multiple frequencies within the lowest band. We observe that the current response scales linearly with the forcing, providing experimental verification that data is taken in the linear response regime. Broadening of the current response spectrum for increasing lattice depth, interaction strength, and density provides a measure of the rate of dissipation. This dissipation occurs purely due to fermion-fermion collisions, given the absence of phonons or impurities in our potentials. It is observed to require a finite lattice depth in order to break Galilean invariance, as well as to enable Umklapp scattering events, which play a significant role in the dynamics. Measured dissipation rates collapse onto the predictions ofakinetic theory under the wide range of conditions studied.
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DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2634
44 - Sum rule for transport dynamics of ultracold atoms in an optical lattice
Authors: Rhys Anderson1; Fudong Wang2; Peihang Xu1; Vijin Venu1; Stefan Trotzky1; Frederic Chevy3; Joseph Thywissen1
1 University of Toronto 2 South University of Science and Technology 3 Laboratoire Kastler Brossel, Ecole Normale Superieure
Corresponding Author: [email protected]
We observe the satisfaction of the sum rule for the conductivity of neutral fermions in an optical lattice subject to weak harmonic confinement. We measure the conductivity spectrum oftheatoms through observations of the global current response to a perturbative applied force, using a quan- tum gas microscope. The spectrum is measured up to frequencies sufficient to characterize intra- band transport, but well below the bandgap. The spectral weight of the response satisfies thesum rule in the limit of small lattice depth, but diminishes as the depth increases, reflecting anincrease in the band-averaged effective mass. Measured under varying temperatures, densities, interaction strengths, and lattice depths, the spectral weight is shown to be obtainable from a thermodynamic description of the system. Furthermore, it is shown to be unaffected by varying the strength of interactions between the fermions, illustrating a fundamental prediction for conductivity spectra. The spectral weight characterizes the strength of the current response to an impulse, and therefore underpins the resistivity. As our measurements approach a high-temperature regime, its inverse is shown to approach T-linear behaviour.
W1-8 Probing and controlling matter with light II (DCMMP) | Sonder et contrôler la matière avec de la lumière II (DPMCM) / 2635
Optical control of valley pseudospin in 2D semiconductors
Author: Ziliang Ye1
1 University of British Columbia
Corresponding Author: [email protected]
Valley polarization associated with the occupancy in energy degenerate but quantum mechanically distinct valleys in the momentum space resembles the spin polarization in many aspects, including the valley magnetic moment, optical selection rule, and valley hall effect. Atomically thin transition metal dichalcogenides (TMDs), a class of honeycomb-like layered materials with broken inversion symmetry and significant spin-orbital coupling, can host robust valley polarization and therefore become an important platform for studying valley-dependent physics. We demonstrated that the valley polarization in the TMD can not only be initialized and measured but also be manipulated coherently by light(1). Ultrafast valley pseudospin rotation was achieved by leveraging the intense electric field in the fs laser pulse. Both the direction and speed of rotation can be controlled byfine- tuning the dynamic phase difference between the exciton wavefunction in opposite valleys. The pseudospin rotation was reflected in the shift of the photoluminescence polarization orientation. By varying the time delay between the excitation and control pulses, we were able to directly probe the lifetime of the intervalley coherence in monolayer WSe2. In addition, I will discuss how the lifetime of TMD excitons can be significantly improved by hexagonal boron nitride encapsulation, where we observed multiple biexciton species with nontrivial valley configurations(2). (1) Z. Ye, D. Sun, T. F. Heinz, Optical Manipulation of Valley Pseudospin. Nature physics, 13, 26 (2017) (2) Z. Ye, et al., Efficient Generation of Neutral and Charged Biexcitons in Encapsulated WSe2Mono- layers, Nature communications, 9, 3718 (2018)
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DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2636
38 - Radio-frequency spectroscopy of one-dimensional Fermi gases near a p-wave Feshbach resonance
Authors: Scott Smale1; Kenneth Jackson1; Ben Olsen2; Joseph Thywissen1
1 University of Toronto 2 Yale-NUS College
Corresponding Author: [email protected]
Interacting fermions with odd orbital exchange parities are of long-standing interest, but has also proven to be challenging to explore both in materials and with ultracold gases. A p-wave Feshbach resonance is known for several alkali gases, but has been associated with strong loss due to recom- bination. In contrast to broad s-wave resonances, a high closed-channel fraction of the Feshbach dimer is inevitable because the dimer is “stuck” behind a large (typically millikelvin-high) centrifu- gal barrier. The collisional wave function thus has excellent overlap with lower bound states, to which it decays quickly through various channels.
Recently, it has been conjectured that odd-wave collisions in quasi-one-dimensional traps might have a larger open-channel fraction, and thus a higher ratio of elastic-to-inelastic collisions [Zhou 2017, Kurlov 2017]. Since there is no rotation associated with odd-wave collisions in 1D, there is no centrifugal barrier. This may free the Feshbach dimer to have a large spatial extent, much like s-wave dimers.
We have investigated the effects of dimensionality and orbital parity on pairing in a degenerate Fermi gas of potassium (40K) atoms near Feshbach resonances. Dimensionality is controlled by loading atoms into one or two optical lattices, to create ensembles of 2D or 1D samples, respectively. At various s-wave or p-wave scattering lengths, we perform radio-frequency spectroscopy, which can associate or dissociate Feshbach dimers, or cause bound-to-bound transitions. From these spec- tra, we plan to measure the energetic widths of resonances, the nature of the pair wave function, and the strength of short-range correlations, i.e., the contact parameter. The contact is the central quantity in a set of universal relations recently discovered for 3D p-wave gases [Yoshida 2015,Yu 2015,Luciuk 2016], which are anticipated to carry over to 1D [Yin 2018]. Our work aims to under- stand the effect of strong confinement on pairs interacting with exchange-antisymmetric orbital wave functions.
[Kurlov 2017] D. V. Kurlov and G. V. Shlyapnikov, Two-body relaxation of spin-polarized fermions in reduced dimensionalities near a p-wave Feshbach resonance, Phys. Rev. A 95, (2017). [Luciuk 2016] C. Luciuk, S. Trotzky, S. Smale, Zhenhua Yu, Shizhong Zhang, J. H. Thywissen, Evi- dence for universal relations describing a gas with p-wave interactions, Nature Physics 12, 530 (2016). [Yin 2018] X. Yin, X.-W. Guan, Y. Zhang, H. Su, and S. Zhang, Momentum distribution and contacts of one-dimensional spinless Fermi gases with an attractive p-wave interaction. Phys. Rev. A98, 023605 (2018). [Yoshida 2015] S. M. Yoshida and M. Ueda, Universal High-Momentum Asymptote and Thermody- namic Relations in a Spinless Fermi Gas with a Resonant p-Wave Interaction, Phys. Rev. Lett. 115, 135303 (2015). [Yu 2015] Z. Yu, J. H. Thywissen, S. Zhang, Universal relations for a Fermi gas close to ap-wave interaction resonance, Phys. Rev. Lett. 115, 135304 (2015). [Zhou 2017] L. Zhou and X. Cui, Stretching p-wave molecules by transverse confinement, Phys. Rev. A 96, 030701 (2017).
M1-3 Magnetism and Heavy Fermions I (DCMMP) I Magnétisme et fermions lourds I (DPMCM) / 2637
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Geometric Magnetic Frustration in Correlated Metallic Systems
Author: S R Dunsiger1 Co-authors: K Akintola 2; S W Cheong 3; K H Chow 4; A M Coté 5; M Dehn 6; A C Y Fang 2; J C Gallagher 7;S Gheidi 2; N Hur 3; K H Kim 8; J Lee 2; L Liu 9; G M Luke 10; G D Morris 1; E D Mun ; T M S Munsie 10; J E Sonier 2;S Sundar 2; F Y Yang 7
1 TRIUMF 2 Simon Fraser University 3 Rutgers University 4 University of Alberta 5 Kwantlen Polytechnic University 6 University of British Columbia 7 The Ohio State University 8 Seoul National University 9 Columbia University 10 McMaster University
Corresponding Authors: [email protected], [email protected]
Systems based on lattices of triangular or tetrahedral units with nearest neighbour antiferromag- netic exchange interactions are the archetypal examples of geometric magnetic frustration, offering a means of accessing novel ground states. Rich phenomenology has similarly been observed in exten- sive investigations of Ce (4f1) and Yb (4f13) based intermetallic compounds, including heavy fermion behaviour, unconventional superconductivity, or non-Fermi liquid responses in the proximity of a quantum critical point. The ground states of these systems are considered to be mainly governedby the competition between the Kondo and the Ruderman - Kittel - Kasuya - Yosida (RKKY) exchange interaction, both mediated by the conduction electrons. Combining these two arenas, whereas ear- lier investigations concentrated on insulators, there are an increasing number of studies of frustrated magnetism in metallic systems. For example, CeCd3As3 is one member of a family of rare earth ternary compounds which crystallise into a hexagonal ScAl3C3-type structure, where the magnetic Ce-ions form a quasi two dimensional anisotropic triangular lattice. Such model systems have been proposed as candidates for quantum spin liquid behaviour [1]. I report a specific heat and muon spin relaxation investigation of thelow temperature ordered phase and associated spin fluctuations of this material. Magnetic systems based on 5d transition metal ions on the pyrochlore lattice are another example, offering a unique opportunity to explore the exotic ground states which potentially arise whenthe electron-electron Coulomb interaction, electronic bandwidth and spin orbit coupling are all of com- parable magnitude. I will compare magnetisation and muon spin relaxation investigations in a series of 4d Mo4+ and Ru4+, as well as 5d Ir4+ based pyrochlores, which may be controllably tuned through a metal insulator transition, providing insight into the magnetic excitations as these finely balanced systems evolve from a localised to itinerant spin character. [1] P. Fazekas and P. Anderson, Philos. Mag. 30, 423 (1974)
M1-11 Probing and controlling matter with light I (DCMMP) | Sonder et contrôler la matière avec de la lumière I (DPMCM) / 2638
Photoinduced gap renormalization and many-body recombina- tion in insulating cuprates
Authors: Derek G. Sahota1; Ruixing Liang2; Maxime Dion3; Patrick Fournier3; Hanna A. Dabkowska4; Graeme M. Luke4; J. Steven Dodge1
Page 128 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 Simon Fraser University 2 University of British Columbia 3 Université de Sherbrooke 4 McMaster University
Corresponding Authors: [email protected], [email protected]
We study the pump-probe response of three insulating cuprates as a function of both pump and probe photon energies, time, and fluence. The fluence dependence follows a simple and universal analytical form that includes a characteristic volume scale, which we associate with the effective interaction volume for a photoexcitation. This characteristic size varies strongly with pump photon energy, with a maximum just above the charge-transfer absorption peak. We assign this behavior to ultrafast many-body recombination in the photocarrier kinetics, characterized by an anomalously large Auger coefficient.
DPE Poster Session & Student Poster Competition Finals (5) | Session d’affiches DEP et finales du concours d’affiches étudiantes (5) / 2639
11 - Open Textbooks - we have led the horses to water – now what?
Author: Jennifer Kirkey1
1 Douglas College
Corresponding Author: [email protected]
The use of open textbooks in increasing dramatically in first year physics courses. This posterwill present the result of scholarly research around student perceptions, the use and impact of open textbooks as well as suggestions for how instructors might change what they do in their classroom around their use of open textbooks. Comparing and contrasting student’s attitudes in first year physics, astronomy and biology classes to open textbooks is the theme of this poster. It will also relate attitudes towards open educational resources (OER) to simple demographic information and the overall cost of textbooks to determine whether there are indicators that can be measured a priori to suggest that students in a particular course may be more or less receptive to the incorporation of OER. More than 300 students were surveyed in 10 courses over two years at Douglas College so there is enough data to form interesting correlations. Procedures, promises, pitfalls, and the possibility of conducting further replications at multiple in- stitutions across BC will be analyzed. The data has suggestions about the utility and ease of encour- aging widespread adoption of OER in British Columbia and elsewhere. What might instructors change about their use and adaptations of open textbooks in response to students’ opinions? Replicating previous studies on open textbooks to allowed comparisons of students at Douglas Col- lege with those from other postsecondary institutions in BC and in the USA. This was the first time I, a physical scientist, had done any type of social science research. Ihave learned a lot in the last two years. Come and learn from the ethical and data collection challenges that were faced, let us discuss how to ensure data reliability from student surveys, and how to discern the best way to analyze such data. The questions that were asked included demographic questions as well as questions suchas“How often does your instructor encourage you to read your textbook?” and “What is your best estimateof the percentage of exam questions that could be correctly answered using only the textbook?” I will share how the student perceptions have changed what I and other instructors do in their courses, and how they might change what you do in your classroom. It is more than about saving
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money for students. Open textbooks can change how you teach. Open your mind to open text- books.
W1-8 Probing and controlling matter with light II (DCMMP) | Sonder et contrôler la matière avec de la lumière II (DPMCM) / 2640
Optical second harmonic susceptibility in the Weyl semimetal tungsten telluride
Author: Leya Lopez.L1
Co-authors: Saeid Kamal 2; Eundeok Mun 1; J. Steven Dodge 1
1 Department of Physics, Simon Fraser University, Canada 2 Department of Chemistry, University of British Columbia, Canada
Corresponding Authors: [email protected], [email protected]
A recent study on the Weyl semimetal tantalum arsenide showed that it has an unusually large second-order nonlinear optical susceptibility [1]. Subsequently, models that connect the band-structure geometry and the nonlinear susceptibility were established to explain this anomaly [2],[3]. Here we study second harmonic generation (SHG) in another acentric semimetal, tungsten telluride (WTe2), and measured its nonlinear second-order nonlinear optical susceptibility χ(2). WTe2 has an orthorhombic crystal structure with C2v point group sym- metry. It is a layered material that has a natural cleavage plane perpendicular to the c-axis, but lacks optical-quality facets along its edges. However, for light at normal incidence, the constraints imposed by crystal symmetry imply that SHG is observable only for light reflected from the edges of the crystal, not from the natural planar surface. Hence, we measure the SHG in a confocal mi- croscope, where it is easier to measure the second harmonic generation from the striated edges of the crystal. For the same illumination conditions, we find that the SHG intensity from GaAs and WTe2 are comparable, which suggests that the χ(2) of WTe2 is comparable to or greater than that of GaAs. We also compare our results to theoretical calculations that predict the second-order nonlinear response of various Weyl semimetals [3].
1. Wu, L. et al., Giant anisotropic nonlinear optical response in transition metal monopnictide Weyl semimetals, Nat. Phys. 13, 350-355 (2017). 2. Patankar, S. et al., Resonance-enhanced optical nonlinearity in the Weyl semimetal TaAs, Phys. Rev. B 98, 165113 (2018). 3. Zhang, Y. et al., Berry curvature dipole in Weyl semimetal materials: An ab initio study, Phys. Rev. B 97, 041101 (2018).
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2641
31 - Thermal Conductances of Silicon Phononic Crystals by Molec- ular Dynamics
Authors: Alexander Robillard1; Ralf Meyer2
1 Laurentian 2 Laurentian University
Page 130 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
Silicon nanostructures are candidates for thermoelectric materials and can be used to effectively harvest energy if they can be designed in such a way as to improve their thermodynamic figure of merit. In silicon this is achieved primarily by reducing thermal conductivity through clever de- sign minimizing heat transport. Phononic crystals are a form of acoustic metamaterial that aim to do this through periodic inclusions in a larger nanostructure. First, the design and application of phononic crystals is discussed. We then present the thermal conductances, a quantity related to the thermal conductivity, of honeycomb silicon phononic crystals calculated using molecular dynamics simulations. Calculations show that the presented phononic crystals exhibit greatly reduced ther- mal conductances, and their length scaling is different from bulk and nanowire systems, indicating differences in the primary mechanisms of heat transport.
T4-5 Topological materials (DCMMP) | Matériaux topologiques (DPMCM) / 2642
Magnetotransport in topological metals
Author: Anton Burkov1
1 University of Waterloo
Corresponding Author: [email protected]
Topological metals continue to attract attention as novel gapless states of matter. While there bynow exists an exhaustive classification of possible topologically nontrivial metallic states, their observable properties, that follow from the electronic structure topology, are less well understood. In this talk I will present my recent work on magnetotransport phenomena in topological metals, which may be related to the chiral anomaly. I will demonstrate that the chiral anomaly leads to strong anisotropic magnetoresistance in such materials, which manifests in very unusual negative longitudinal magnetoresistance and planar Hall effect. I will also argue that a smoking-gun feature of the chiral anomaly in topological metals is the existence of propagating chiral density modes even in the regime of weak magnetic fields. Finally, I will show that the optical conductivity ofsuch metals exhibits an extra peak, which exists on top of the standard metallic Drude peak. The spectral weight of this peak is transferred from high frequencies and its width is proportional to the chiral charge relaxation rate.
T3-9 Cosmology (DTP) | Cosmologie (DPT) / 2643
Probing Dark Energy with CHIME
Author: Richard Shaw1
1 UBC
Corresponding Author: [email protected]
CHIME will use Intensity Mapping of the 21cm line of neutral hydrogen to map large-scale structure between redshifts of 0.8 and 2.5. By measuring Baryon Acoustic Oscillations (BAO) we will place constraints on the dark energy equation of state as it begins to dominate the expansion of the Universe, particularly at redshifts poorly probed by current BAO surveys. In this talk I will introduce CHIME, a transit radio interferometer designed specifically for this purpose. I will discuss the promise and pitfallsof Intensity Mapping and describe how we plan to confront the many challenges of such observations, in particular removal of astrophysical foregrounds which are
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six orders of magnitude larger than the 21cm signal. CHIME started operating at the DRAO in Penticton, BC at the end of 2018 and I will report on current progress and lessons already learned.
M1-7 Identity and Physics Education (DPE/CEWIP) | Identité et enseignement de la physique (DEP/CEFEP) / 2644
Understanding identity and social networks among women in graduate physics education
Author: Allison Gonsalves1
1 Prof.
Corresponding Author: [email protected]
The success and persistence of women and other under-represented minorities in physics post- secondary education has been studied from numerous perspectives. Recently, researchers have suggested that success and persistence in physics depends on the development of a strong physics- identity. However, to form a complex picture of how students access resources that contribute to the development of physics identities, it is necessary to understand the formal and informal struc- tures and relationships at the university and beyond which support them. We know that under- represented students, especially women, tend to persist in physics if they become involved in ini- tiatives such as equity, diversity and inclusion (EDI) in physics campus groups. Despite evidence that participation in these initiatives can contribute to persistence, we know relatively little about how students access and participate in these initiatives, or how these spaces can facilitate graduate students’ identity work in physics. This presentation explores the usefulness of social network anal- ysis to understand the degree to which these initiatives may create networks of support for students’ identity work in physics. At the same time, I will discuss the potential of studying identity work paired with social network analysis, to capture the social and dynamic aspects of alternative spaces for physics learning and persistence. This theoretical and analytical pairing can to capture the kinds of identity-forming resources that flow through networks, and the social interactions that facilitate identity work in physics. These outcomes and novel framings are significant for faculty andadmin- istrators involved in EDI initiatives to improve the success and persistence of under-represented students in physics.
W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2645
Production of Ultracold Lithium Triplet Dimers by STIRAP
Author: Denis Uhland1 Co-authors: Erik Frieling 1; Gene Polovy ; Kirk Madison 2
1 University of British Columbia 2 UBC
Corresponding Authors: [email protected], [email protected], [email protected]
Ultra-cold atomic ensembles have enabled experimental studies of few and many-body quantum phenomena including topological insulators, many-body pairing phenomena, and superfluidity. The use of ultra-cold molecular ensembles is expected to provide access to even richer phenomena than atoms due to their complex internal structure. Cold molecules are also key to studying and under- standing chemistry near T=0 where reactions are dominated by quantum effects. Motivated by this, we have developed an experimental apparatus that can produce Li dimers from laser-cooled Li atoms and, eventually, LiRb molecules from Li+Rb atomic ensembles. Beginning with a gas of Li atoms,
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we form loosely bound Feshbach dimers by evaporation near a Feshbach resonance. We then ma- nipulate the internal state of these molecules, transferring them into deeply bound ro-vibrational 3 + levels of the a(1 Σu ) triplet potential using stimulated Raman adiabatic passage (STIRAP). Having the possibility to transfer an ultra-cold molecular ensemble to different quantum states immediately opens the window for studies in ultra-cold chemistry.
T3-7 Frontiers in optics (DAMOPC) | Frontières en optique (DPAMPC) / 2646
Vector beams, high harmonic generation and sub-focal spot co- herent control
Author: Paul Corkum1
1 University of Ottawa
Corresponding Author: [email protected]
Abstract: We use intense vector beams to generate high harmonics or to create solenoidal currents in solids or gases. We predict THz magnetic fields reaching the scale of those only available atuser facilities. In the visible and infrared we can transform Gaussian beams into beams with spatially dependent polarization and/or phase structures. Orbital angular momentum is given to a beam when the phase varies by 2npi around its profile. One might ask if orbital angular momentum is conserved during high-harmonic generation? We show the conservation of orbital angular momentum [1] during high harmonic generation and show how the conservation of angular momentum leads to a method for coupling a controlled orbital angular momentum on any harmonic [2]. Our results open a pathway for attosecond science with similarly structured light. Besides shaping the wave fronts, a Gaussian beam can also be transformed into beams with complex polarization states – so called vector beams. We use an 800 nm, 2 mJ pulse, 35 fs pulse and a Q-plate (illustrated in the inset) to produce a vector beam with each quadrant circularly polarized, with adjacent quadrants delayed in phase by pi/2 and with different handedness for adjacent quadrants (encoded in red and blue in the figure). Assuch a vector beam propagates, it transforms into a beam with linearly polarized segments as illustrated (bottom left) and measured (bottom, middle). We transform this beam via high-harmonic generation to photon energy of 40 eV creating a new vector beam with linearly polarized segments and also with adjacent quadrants phase delayed by npi/2 where n is the harmonic order. For symmetric nonlinear media, this beam likewise transforms as it propagates into a beam with circularly polarized segments as illustrated in the 3-dimensional figure. Cylindrical symmetric vector beams can be efficiently compressed to few cycles in hollow-core fibers and we conclude by discussing opportunities that arise from sub-focal spot coherent control with vector beams [3] allowing THz solenoidal magnetic field generation. [1] G. Gariepy, et al, “Creating High-Harmonic Beams with Controlled Orbital Angular Momentum”, Phys. Rev. Lett. 113, 153901 (2014) [2] F. Kong, et al, “Controlling the orbital angular momentum of high harmonic vortices”, Nat. Com- mun. 8, 14970 (2017) [3] S. Sederberg, F. Kong, and P. B. Corkum, ”Ultrashort Magnetic Impulses Driven by Coherent Control with Vector Beams”, Arxiv 1901.07444v1 (2019)
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2647
53 - Production of Ultracold Lithium Triplet Dimers by STIRAP
Page 133 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Denis Uhland1 Co-authors: Erik Frieling 1; Gene Polovy ; Kirk Madison 2
1 University of British Columbia 2 UBC
Corresponding Authors: [email protected], [email protected], [email protected]
Ultra-cold atomic ensembles have enabled experimental studies of few and many-body quantum phenomena including topological insulators, many-body pairing phenomena, and superfluidity. The use of ultra-cold molecular ensembles is expected to provide access to even richer phenomena than atoms due to their complex internal structure. Cold molecules are also key to studying and under- standing chemistry near T=0 where reactions are dominated by quantum effects. Motivated by this, we have developed an experimental apparatus that can produce Li dimers from laser-cooled Li atoms and, eventually, LiRb molecules from Li+Rb atomic ensembles. Beginning with a gas of Li atoms, we form loosely bound Feshbach dimers by evaporation near a Feshbach resonance. We then ma- nipulate the internal state of these molecules, transferring them into deeply bound ro-vibrational 3 + levels of the a(1 Σu ) triplet potential using stimulated Raman adiabatic passage (STIRAP). Having the possibility to transfer an ultra-cold molecular ensemble to different quantum states immediately opens the window for studies in ultra-cold chemistry.
W2-6 Local probes (DCMMP) | Sondes locales (DPMCM) / 2648
Ultrafast terahertz microscopy: from near fields to single atoms
Authors: Tyler Cocker1; Dominik Peller2; Markus Huber3; Fabian Mooshammer2; Markus Plankl2; Fabian Sandner2; Leonardo Viti4; Jessica Boland5; Miriam Vitiello4; Jascha Repp2; Rupert Huber2
1 Michigan State University 2 University of Regensburg 3 University Regensburg 4 NEST, CNR 5 University of Manchester
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
A new experimental frontier has recently emerged with the potential to significantly impact physics, chemistry, and materials science: the regime of ultrafast time resolution and ultrasmall spatial res- olution. This is the domain in which single atoms, molecules, and electronic orbitals move. Italso corresponds, on larger length scales, to the territory of low-energy elementary excitations such as plasmons, phonons, and interlevel transitions in excitons. These processes are of particular impor- tance for nanomaterial functionality and typically survive for only femtoseconds to picoseconds after photoexcitation. In this talk, I will show how these diverse dynamics can be studied with new techniques that combine terahertz technology with scanning probe microscopy. First, I will describe how ultrafast near-field microscopy has been employed to perform sub-cycle spectroscopy of single nanoparticles [1], reveal hidden structure in correlated electron systems [2], resolve transient interface polaritons in van der Waals heterostructures [3], and characterize the electronic properties of topological insulator surfaces [4]. Then I will discuss the development of a new technique: lightwave-driven terahertz scanning tunneling microscopy [5-7]. In this novel approach, the oscillating electric field of a phase- stable, few-cycle light pulse at an atomically sharp tip can be used to remove a single electron from a single molecular orbital within a time window faster than an oscillation cycle of the terahertz wave. I will show how this technique has been used to take ultrafast snapshot images of the electron density in single molecular orbitals and watch the motion of a single molecule for the first time [6].
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[1] M. Eisele et al., Nature Photon. 8. 841 (2014). [2] M. A. Huber et al., Nano Lett. 16, 1421 (2016). [3] M. A. Huber et al., Nature Nanotech. 12, 207 (2017). [4] F. Mooshammer et al., Nano Lett. 18, 7515 (2018). [5] T. L. Cocker et al., Nature Photon. 7, 620 (2013). [6] T. L. Cocker et al., Nature 539, 263 (2016). [7] V. Jelic et al. Nature Phys. 13, 591 (2017).
T2-1 Soft Matter AM-2 (DCMMP) | Matière molle AM-2 (DPMCM) / 2649
Random phase approximation and renormalized Gaussian chain for charged hetero-biopolymers and their sequence-specific phase behavior
Authors: Yi-Hsuan Lin1; Hue Sun Chan1; Kingshuk Ghosh2
1 University of Toronto 2 University of Denver
Corresponding Authors: [email protected], [email protected], [email protected]
The liquid-liquid phase separation in biological systems has recently attracted intense interestin molecular biology, biophysics, and polymer sciences. Intrinsically disordered proteins (IDPs), pro- teins that do not fold into a unique structure when isolation because of the depletion in hydropho- bicity and the abundance of polar, charged, and aromatic residues, have been discovered to undergo liquid-liquid phase separation in the cell, constructing various intracellular membraneless organelles with distinct biomolecular compositions and biological functions. Based on the sequence-function principle in molecular and structural biology, the phase behavior of a charged IDP must be deter- mined by its unique amino acid sequence, the charge distribution on which is not necessarily fixed but can also be modified by phosphorylation or change of pH value. To understand phase separation in biology, we develop a sequence-specific random phase approximation (RPA) theory for charged IDPs. In addition, we take into account the sequence-specific structure factor of charged polymers by utilizing a variation principle to approximate the IDP by a Gaussian chain with an effective Kuhn length. We apply the theory to both polyelectrolytic biopolymers with large net charges and nearly- neutral polyampholytic IDPs with almost equal number of opposite charges, and obtain theoretical predictions consistent with experimental observations. Phase behavior under the influence of salt and counter ions is also investigated. The augmented renormalized-Gaussian RPA theory, termed rG-RPA, is a general theory for polymers with arbitrary charge sequences, providing a concise the- oretical framework for not only studying sequence specificity in individual biopolymer systems but also conducting high-throughput sequence analysis.
T4-7 Optical Spectroscopy and control (DAMOPC) | Spectroscopie optique et contrôle (DPAMPC) / 2650
Near-Unitary Spin Squeezing with Ytterbium
Authors: Boris BravermanNone; Akio KawasakiNone; Edwin Pedrozo-PenafielNone; Simone ColomboNone; Chi ShuNone; Zeyang LiNone; Enrique MendezNone; Megan YamoahNone; Leonardo SalviNone; Daisuke AkamatsuNone; Yanhong XiaoNone; Vladan VuleticNone
State of the art atomic sensors operate near the standard quantum limit (SQL) of projection noise, where the precision scales as the square root of the particle number. Overcoming this limit by us- ing atom-atom entanglement such as spin squeezing is a major goal in quantum metrology. Spin squeezing can be realized by coupling an atomic ensemble to a high-finesse optical resonator, where the resulting collective atom-light interaction allows for both measurement and cavity feedback squeezing. These methods for entangling the atoms are typically non-unitary and generate more
Page 135 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
anti-squeezing than the minimum prescribed by the uncertainty principle, due to a residual entan- glement between the atomic ensemble and undetected probing photons. We find that non-unitarity significantly lowers the potential metrological gain from squeezing in atomic clocks and other quan- tum sensors. To generate near-unitary spin squeezing experimentally, we couple an ensemble of approximately 1000 Yb-171 atoms to a high-finesse asymmetric micromirror cavity. A laser pulse induces an effec- tive one-axis twisting Hamiltonian, producing the desired squeezed spin state, while detuning the probing light from atomic and cavity resonance by several linewidths limits the undesirable entan- glement between atoms and light. We characterize the produced SSSs by state tomography, directly observing a variance reduction of 9.4(4) dB below the SQL, limited by detection noise. For this level of squeezing, we infer a state area only 30% higher than the limit set by the uncertainty principle, con- firming the production of a nearly pure spin squeezed state. This experimental platform will allow for the creation of quantum states with metrologically useful entanglement on the clock transition of Yb-171.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2651
78 - LED-Based Detector Calibration Studies for the SuperCDMS SNOLAB Experiment
Author: Muad Ghaith1
1 Queen’s University
Corresponding Author: [email protected]
SuperCDMS at SNOLAB is a direct search experiment for dark matter, targeting dark matter particles with low mass (≤ 10 GeV/c2). In order to achieve the projected sensitivity, a lower background, in addition to lower threshold energy, are a necessity. In the past, detector calibration was performed using radioactive sources. Currently, we are exploring the possibility of using LED-based calibration methods. In my talk, I will discuss measurements using LEDs of various wavelengths operated at cryogenic temperatures to study the detector stability. Moreover, I will report the progress made using this new method for detector calibration.
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2652
Dark Absorption in SuperCDMS Soudan
Author: Eleanor Fascione1
1 CERN
Corresponding Author: [email protected]
The Super Cryogenic Dark Matter Search (SuperCDMS) uses cryogenic semiconductor detectors to search for dark matter, primarily in the form of Weakly Interacting Massive Particles (WIMPs) scattering off of target nuclei. However, there are promising dark matter candidates that areabsorbed by bound electrons in a manner analogous to the photoelectric effect, a process referred to as dark absorption. The dark photon is a hypothetical new massive vector boson, which acts as a mediator between the visible and hidden sectors by kinetically mixing with the Standard Model photon. Axions and axion like particles (ALPs) are pseudoscalar bosons that result from the spontaneous breaking of a new global symmetry. Relic dark photons and ALPs are both viable dark matter candidates to which SuperCDMS would be sensitive.
Page 136 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
I will discuss the use of data from SuperCDMS Soudan to set limits on the kinetic mixing of dark photons and the effective coupling strength of ALPs.
R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2653
Measurements of proton-carbon differential cross-sections at 20, 30, and 120 GeV/c in EMPHATIC experiment
Author: Matej Pavin1
1 TRIUMF
Corresponding Author: [email protected]
Neutrino parent particles in atmospheric and accelerator-based neutrino experiments are produced in hadronic interactions. Tagging of individual neutrinos and their ancestors is currently not possi- ble. Therefore, we rely on Monte Carlo models and available hadron production data to predict neu- trino fluxes. Without additional hadron production measurements, many neutrino measurements such as neutrino-nucleus cross-section measurements will be limited by the flux uncertainty. This talk will discuss new results from EMPHATIC - a tabletop hadron production experiment at the Fermilab Test Beam Facility. The results include measurements of differential proton-carbon cross- sections at 20, 30 and, 120 GeV/c.
R2-8 Ultracold Neutrons (DNP/PPD) | Neutrons ultrafroids (DPN/PPD) / 2654
A new measurement of the permanent electric dipole moment of 129-Xe using 3-He comagnetometry and SQUID detection
Authors: Florian KuchlerNone; Earl Babock1; Martin Burghoff2; Tim Chupp3; Skyler Degenkolb4; Isaac Fan2; Peter Fierlinger5; Eva Kraegeloh3; Wolfgang Kilian2; Sylvia Knappe-Grueneberg2; Tinhao Liu2; Michael Marino5; Jonas Meinel5; Natasha Sachdeva3; Zahir Salhi1; Allard Schnabel2; Jaideep Singh6; Stefan Stuiber5; William Terrano5; Lutz Trahms2; Jens Voigt2
1 Jülich Center for Neutron Science 2 Physikalisch-Technische Bundesanstalt (PTB) Berlin 3 Department of Physics, University of Michigan 4 Institut Laue-Langevin 5 Excellence Cluster Universe and Technische Universität München 6 National Superconducting Cyclotron Laboratory and Department of Physics & Astronomy, Michigan State University
Corresponding Author: [email protected]
Permanent electric dipole moments (EDMs) arise due to the breaking of time-reversal or, equiva- lently, CP-symmetry. Although EDM searches have so far only set upper limits, which are many orders of magnitude larger than Standard Model (SM) predictions, the motivation for more sensitive EDM searches is stronger than ever. The HeXe EDM experiment is using SQUIDs to detect the freely precessing nuclear spins of 129-Xe and 3-He to form a co-magnetometer in a very low magnetic field inside a high performance mag- netically shielded room. The noble gas nuclei of 129-Xe and 3-He are simultaneously polarized by spin-exchange optical pumping using the rubidium D1 line at 795 nm. The newly developed EDM cells using silicon electrodes are filled with polarized gas directly from the optical pumping celland then transferred into the magnetically shielded room. Inside, after applying a pi/2 pulse, both species can freely precess in the presence of applied magnetic and electric fields with transverse relaxation time constants beyond 4000 s. Low frequency precession signals are detected by SQUID sensors inside a liquid helium dewar with typical magnetic field noise density below 10 fT/sqrt(Hz).
Page 137 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
In this talk I will report on the measurements leading to an improved limit on the EDM of 129- Xe.
DNP Poster Session & Student Poster Competition Finals (1) | Session d’affiches DPN et finales du concours d’affiches étudiantes (1) / 2655
61 - First high voltage breakdown measurements in a test setup for the TUCAN neutron EDM experiment
Authors: Florian KuchlerNone; Rüdiger Picker1
1 TRIUMF
Corresponding Authors: [email protected], [email protected]
The currently established best limit on the neutron EDM was obtained by eliminating andinvesti- gating main systematic effects using an atomic co-magnetometer inside the neutron storage volume. The next generation neutron EDM search pursued by the TUCAN collaboration aims to introduce 129-Xe as an additional co-magnetometer due to its low neutron absorption cross section. An optical detection scheme of 129-Xe spin precession is available using a two-photon transition. Ultimately, the goal is an optically probed dual co-magnetometer using both 129-Xe and 199-Hg inside the neutron storage cell to further improve understanding and cancellation of limiting sys- tematic effects. While 199-Hg is an established co-magnetometer in high electric fields, xenonhas to be studied for its dielectric properties in the pressure range of interest. A test setup at TRIUMF is in operation to measure the high-voltage breakdown properties of gases at total pressures of 1e-2 to 1e-4 mbar. First results from high-voltage breakdown tests using various gases will be presented.
W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2656
Stable longitudinal spin domains in a nondegenerate ultracold gas
Author: Sean Graham1
Co-authors: Dorna Niroomand 1; Robert J. Ragan 2; Jeffrey McGuirk 1
1 Simon Fraser University 2 University of Wisconsin - La Crosse
Corresponding Authors: [email protected], [email protected]
We demonstrate that linear effective magnetic fields can stabilize longitudinal spin domains ina weakly-interacting gas of 87Rb atoms above quantum degeneracy. Coherent spin-rotating interac- tions are modified by applying a small linear effective magnetic field that varies the localLarmor precession. Adding small linear effective magnetic fields with gradients that oppose the initial spin gradient in the domain wall stabilizes the spin domains. We experimentally determine these stabiliz- ing gradients over a range of cloud temperatures and densities, and compare to a quantum Boltzmann theory in the hydrodynamic regime.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2657
Page 138 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
45 - Modifying spin transport in a one-dimensional nondegener- ate ultracold gas
Author: Sean Graham1 Co-authors: Dorna Niroomand 1; Robert J. Ragan 2; Jeffrey McGuirk 1
1 Simon Fraser University 2 University of Wisconsin - La Crosse
Corresponding Authors: [email protected], [email protected]
We study the transport of spin within a weakly-interacting gas of 87Rb atoms above quantum de- generacy. Spin transport can be modified by tuning coherent spin-rotating interactions with asmall effective magnetic field that varies the local Larmor precession. Previously, we have shownthat specific linear effective magnetic fields stabilize spin domains [1]. Further manipulation oftheef- fective magnetic field is achieved by utilizing a digital micromirror device. This finer controlofthe effective magnetic field can lead to longer lived stable spin domains, multiple stable spindomains, and dynamic control of the orientation of a spin domain. We present the experimental details of including a digital micromirror device to our system and our progress on further modifying spin transport. [1] S. D. Graham, D. Niroomand, R. J. Ragan, and J. M. McGuirk, Phys. Rev. A 97, 051603(R) (2018)
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2658
7 - Beam physics models of the TRIUMF linear accelerators for advanced beam tuning methods
Authors: Olivier Shelbaya1; Spencer Kiy1 Co-authors: Oliver Kester 1; RICK BAARTMAN 1
1 TRIUMF
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
A detailed understanding of the beam physics of accelerators is required to move towards a new beam tuning paradigm that involves automatic tuning of accelerators. A complete end-to-end model is required so that high level tuning algorithms can be applied. Therefore, an end-to-end simulation of the ISAC accelerators, which doesnot exist is now under development. We have established an analytical model of the linacs using the methodology of a Hamiltonian based description of beam line elements and implemented this through a sophisticated simulation code TRANSOPTR. This will enable an automatic re-phasing of cavities of the linac of TRIUMF’s Isotope Separator and ACelerator facility, to improve beam delivery in case of RF-phase drifts or failure of one of the SRF cavities in ISAC-II. This activities also prepare potential applications of machine learning in the tuningof complex accelerator systems.
M2-8 General Relativity I (DTP) | Relativité générale I (DPT) / 2659
Coulombic contribution to angular momentum flux in general relativity
Author: Eric PoissonNone Co-author: Beatrice Bonga 1
Page 139 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 Perimeter Institute
Corresponding Author: [email protected]
The flux of angular momentum in electromagnetism cannot be expressed entirely in termsofthe field’s radiative degrees of freedom. Its expression also involves Coulombic pieces of the field, inthe form of a charge aspect q(theta,phi), a function of polar angles whose integral gives the total charge of the system. Guided by the strong analogy between radiative processes in electromagnetism and gravitation, we ask whether the flux of angular momentum in general relativity might also involve Coulombic pieces of the gravitational field. Further, we ask whether such terms might have been missed in the past by specializing the flux to sources of gravitational waves that are at rest with respect to the frame in which the flux is evaluated. To answer these questions we bring together the Landau-Lifshitz formulation of the Einstein field equations, which provides specific definitions for angular momentum and its associated flux, and the Bondi formalism, which provides a systematic expansion of the metric of an asymptotically flat spacetime in inverse powers of the distance away from the matter distribution. We obtain a new expression for the flux of angular momentum, whichis not restricted to sources of gravitational waves at rest nor to periodic sources. We show that our new expression is equivalent to the standard formula used in the literature when these restrictions are put in place. We find that contrary to expectations based on the analogy between electromagnetism and gravitation, the flux of angular momentum in general relativity can be expressed entirely in terms of the field’s radiative degrees of freedom. In contrast to electromagnetism, no Coulombic information is required to calculate the flux of angular momentum in general relativity.
W2-9 Hadronic Physics (DNP/DTP) | Physique hadronique (DPN/DPT) / 2660
Compton Scattering and the Nucleon Polarizabilities
Author: David Hornidge1
1 Mount Allison University
Corresponding Author: [email protected]
A central problem of modern physics research is the solution to QCD in the non-perturbative regime. One method of testing QCD in this low-energy region is by measuring certain structure constants of hadrons - called polarizabilities - that show particular promise of allowing a direct connection to the underlying quark/gluon dynamics through comparison to modern QCD-inspired model calculations, and to solutions of QCD done computationally on the lattice. This talk will give an overview of recent and upcoming measurements to obtain the polarizabilities of both the proton and neutron.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2661
64 - The Mont Blanc neutrino burst from Supernova 1987A
Author: Stanley Yen1
1 TRIUMF
Corresponding Author: [email protected]
Neutrinos from Supernova 1987A were detected in coincidence in 3 different detectors (Baksan, IMB and Kamioka). However, only the Mont Blanc detector registered an early burst 4.7 hours before the other 3 detectors. This paper examines possible explanations for the non-observation ofthe early burst in the 3 detectors, and the possible astrophysical scenarios for a double burst, such as a
Page 140 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
QCD phase transition to quark matter. Future multi-flavour capability by combining hydrogenous detectors with detector primarily sensitive to νe like the proposed HALO-1kT could help resolve this issue for future galactic core-collapse supernovae.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2662
Diffusion-controlled drug delivery: Avoiding pitfalls when using Lattice Monte Carlo (LMC) simulations
Authors: Gary W. Slater1; Mehran Bagheri2; Maxime Ignacio3
1 Université d’Ottawa 2 University of Ottawa 3 École Polytechnique
Corresponding Authors: [email protected], [email protected]
Lattice Monte Carlo (LMC) methods are frequently used to model drug delivery systems. Inatypical case, the drug, initially encapsulated in a porous material (e.g., a hydrogel), is released via two pro- cesses: (i) disintegration of the material and (ii) diffusive escape. One way to control diffusive release is to design layered materials with regions that have different porosities. However, modelling inho- mogeneous systems where both the porosity and the diffusivity are space-dependent is ambiguous in LMC simulations. In this talk, we examine two fundamental issues: 1) how to replace connected regions with different porosities by free-solution regions of different effective viscosities; 2)how to treat the LMC jumps between regions with different effective viscosities. We present computa- tional and theoretical studies of 2D systems consisting in two different sets of immobile obstacles that create two media with different effective viscosities, as well as their equivalent obstacle-free 1D systems with effective diffusion coefficients. Using this toy model, we examine how interfacial diffusion is treated by the various flavours of stochastic calculi, and we demonstrate that Isothermal calculus is the correct choice as opposed to the generally employed Ito calculus. We then explore the corrections that must be considered to simplify such inhomogeneous systems while conserving the proper static and dynamic properties of the original system.
T2-5 Quantum magnetism (DCMMP) | Magnétisme quantique (DPMCM) / 2663
Quantum magnetism in honeycomb lattice materials
Author: Young-June Kim1
1 University of Toronto
Corresponding Author: [email protected]
Enormous interests generated by graphene physics have made honeycomb lattice one of the most studied two-dimensional lattice structures in recent years. In particular, the realization that bond- dependent anisotropic magnetic interactions can be found in honeycomb lattice materials with strong spin-orbit coupling has made a profound impact on quantum magnetism research. In this contribution, we will give an overview of recent experimental progress made in understanding hon- eycomb lattice quantum magnets with a special emphasis on the so-called Kitaev materials, such as α-RuCl3, which is a leading candidate for realizing a quantum spin liquid phase. Prospects of incorporating such honeycomb lattice quantum magnets in an artificial heterostructure with other two-dimensional materials will be also discussed.
Page 141 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
W1-11 Neutrinoless Double Beta Decay (DNP/PPD) | Double désintégration bêta sans neutrino (DPN/PPD) / 2664
Characterization and development of a new SiPM with high VUV sensitivity for the nEXO Experiment
Authors: Giacomo Gallina1; Fabrice Retiere2; Pietro GiampaNone; Peter MargetakNone; Austin de St. Croix3; Fatemeh EdaltafarNone; Nicolas Massacret2
1 TRIUMF 2 Triumf 3 TRIUMF/UBC
Corresponding Authors: [email protected], [email protected], [email protected], giampa- [email protected]
Silicon Photo-Multipliers (SiPMs) have emerged as a compelling photo-sensor solution over the course of the last decade. In contrast to the widely used Photo-Multipliers Tubes (PMTs), SiPMs have high single Photon Detection Efficiency (PDE) with negligible gain fluctuations, are low-voltage pow- ered, optimal for operation at cryogenic temperatures, and have low radioactivity levels. For these reasons, large-scale low-background cryogenic experiments, such as the next-generation Enriched Xenon Observatory experiment (nEXO), are migrating to a SiPM-based light detection system. The current generation of Vacuum UltraViolet (VUV) SiPMs achieve at best 25% PDE below 300 nm com- pared to more than 50% at 420 nm, being limited by reflections and charge carrier collection close to the surface. The aim of this talk is to show a quantitative understanding of the processes thataffect the SiPM performances. In particular we will show how we can describe, for different wavelengths, the SiPM PDE as a function of the bias voltage using a minimum set of parameters extracting: (i) the relative contribution of electrons vs holes, (ii) the length of an effective photon collection region. We will then use this parametrization to describe the SiPM dark noise, after-pulsing and cross-talk. This characterization is part of the development of a new generation of VUV SiPMs withveryhigh efficiency in VUV (>50%) for operation in Liquid Argon and Liquid Xenon.
W1-7 Detectors for Particle Physics (DAPI/PPD) | Détecteurs pour la physique des particules (DPAI/PPD) / 2665
Ionization yield measurements for NEWS-G
Author: Marie VidalNone
Corresponding Author: [email protected]
NEWS-G (New Experiments With Spheres-Gas) is a rare event search experiment using Spherical Proportional Counters (SPCs). Primarily designed for the direct detection of dark matter, this tech- nology also has appealing features for Coherent Neutrino-Nucleus Scattering (CEνNS) studies using nuclear power plants as a neutrino source. For both applications, an important property of the gas to characterize is the ionization yield, or quenching factor, defined as the ratio of the measured energy induced by a nuclear recoil andan electronic recoil of the same energy. Quenching factor measurements in Neon based gas mixtures are being performed at TUNL (Triangle Universities Nuclear Laboratory) using a neutron beam and an array of backing detectors. We will present the set-up and techniques for quenching factor mea- surements and the most recent results obtained from two measurement campaigns.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2666
Page 142 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
91 - Expected Neutron Background for the PICO-500 Detector with Geant4 Simulations
Author: William Woodley1
1 University of Alberta
Corresponding Author: [email protected]
PICO is a direct Dark Matter detection experiment installed at SNOLAB searching for WIMPs (Weakly- Interacting Massive Particles) using the superheated liquid technique. A slight perturbation in the liquid, e.g. energy deposited by a recoiling nucleus due to its elastic collision with an incoming neutron, can create a bubble. The neutron-induced bubbles produce a signal indistinguishable from those induced by the WIMPs. Therefore, understanding and predicting the internal and external expected neutron background is fundamental for the success of the experiment. The next gener- ation detector is PICO-500, which is planned to have an active volume of 500 L of C3F8. During the construction of this detector, a very careful screening of the materials allows for the selection of materials containing low amounts of neutron-emitting isotopes. This presentation will focus on the work being done to simulate the expected neutron background in the PICO-500 bubble chamber using Geant4 simulations and the results.
W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2667
New discoveries and observations of universal physics in colli- sions
Authors: Kirk Madison1; Pinrui Shen2; Erik Frieling3; Denis Uhland1; Roman Krems1; James Booth4
1 UBC 2 University of British Columbia Physics Department 3 University of British Columbia 4 BCIT
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
In physics, universality refers to the existence of properties that are independent of short-range structural details. For example, critical phenomena that are insensitive to the details of microscopic interactions exhibit the same bulk scaling behavior (e.g. critical exponents and scaling functions) for microscopically distinct systems. Such insensitivity of the low-energy degrees of freedom to small scale structures is key in the development of effective field theories, and universality arises in few- body physics when the scattering length is much larger than the interaction range. Universality is therefore a powerful and intuitive avenue for understanding and applying the physics of complex phenomena. In this talk, we present an overview of recent work on two forms of universality in collision physics. We present experimental observations of the universal and non-universal decay rate of ultra-cold, re- active molecules, and we report the discovery of a new form of universality for collisions that occur at very large impact parameters and transfer exceedingly little kinetic energy. We find both theo- retical and experimental evidence that these so-called quantum diffraction collisions are universal and that the energy transferred by them encodes information about the total collision cross section and the form of the interaction potential at long range. This universality phenomenon (which we refer to as QDU) is a manifestation of the Heisenberg uncertainty principle and a consequence of the collision induced particle localization. QDU therefore occurs for any interaction and applies to collisions of both elementary and composite particles (e.g. nuclei, atoms and molecules). Because of its fundamental nature and broad implications to collisions of all types, we believe this discovery is of general interest. Using QDU for van der Waals interactions, we realize a self-defining flux sensor
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using cold atoms providing the first primary and quantum definition of the Pascal applicable toany atomic or molecular species.
M1-8 Neutrinoless Double Beta Decay and Strangeness (DNP) | Double désintégration bêta sans neutrino et étrangeté (DPN) / 2668
Status of the SNO+ experiment
Author: Aleksandra Bialek1
1 SNOLAB
Corresponding Author: [email protected]
The SNO+ experiment is located in SNOLAB (Sudbury, Canada), 2 kilometers underground inthe Creighton mine. It is a large scale, low-background, neutrino detector whose main purpose is to search for neutrinoless double-beta decay. The outcome of the discovery would be a measurement of the half-life for such a process, which is inversely proportional to the effective neutrino mass squared. With 780 tons of liquid scintillator loaded with tellurium, SNO+ is going to explore the Majorana neutrino mass parameter space down to the inverted mass hierarchy region. Designed as a multi-purpose detector, the SNO+ can also detect solar and reactor neutrinos, geo and supernovae neutrinos and perform nucleon decay searches. It is currently filled with ultrapure water and taking data since May 2017 to measure the 8B neutrino flux and constrain the lifetime of nucleon decay through invisible modes in 16O. The results have been published and they will be presented during this talk. The experiment is now moving to the next phase, where the detector will be filled with liquid scin- tillator and subsequently loaded with tellurium.
T3-9 Cosmology (DTP) | Cosmologie (DPT) / 2669
Geometric Inflation
Author: Robie HennigarNone
Co-authors: Pablo Bueno ; Pablo Cano ; Jose Edelstein ; Luisa Jaime ; Gustavo Arciniega
We argue that the presence of an inflationary epoch is a natural, almost unavoidable, consequence of the existence of a sensible effective action involving an infinite tower of higher-curvature corrections to the Einstein-Hilbert action. No additional fields besides the metric are required. We show thata family of such corrections giving rise to a well-posed cosmological evolution exists and automatically replaces the radiation-dominated early-universe Big Bang by a singularity-free period of exponential growth of the scale factor, which is gracefully connected with standard late-time ΛCDM cosmology. The class of higher-curvature theories giving rise to sensible cosmological evolution share additional remarkable properties such as the existence of Schwarzschild-like non-hairy black holes, or the fact that, just like for Einstein gravity, the only degrees of freedom propagated on the vacuum are those of the standard graviton.
W1-8 Probing and controlling matter with light II (DCMMP) | Sonder et contrôler la matière avec de la lumière II (DPMCM) / 2670
Could GaAs (001) Know What Bacterium Has Bitten It?
Author: Jan Dubowski1
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1 Université de Sherbrooke
Corresponding Author: [email protected]
The etching of compound semiconductors with atomic level resolution is of high interest totech- nologies addressing the fabrication of low-dimensional devices, the tunability of their optoelec- tronic properties and the precise control of device surface structure. We have developed an in- novative method of digital photocorrosion (DIP) for shallow (< 200 nm) etching of GaAs/AlGaAs nanoheterostructures with sub-monolayer resolution [1]. The rate and stability of DIP depend on the energy and intensity of photons employed for optical excitation, as well as on the chemistry of a liquid environment surrounding processed samples [2]. The excitation of electron-hole pairs al- lows for convenient application of the photoluminescence (PL) effect for monitoring in situ the DIP process, however similar diagnostics is also available for materials with negligible PL [3]. It is not surprising that the extremely low rate of etching of the investigated GaAs/AlGaAs nanoheterostruc- tures is sensitive to the perturbation induced by electrically charged molecules immobilized in the vicinity of their digitally photocorroding surface. We have taken advantage of this effect in order to develop a DIP-based biosensor of viruses and bacteria [4]. I will discuss some of the fundamental parameters describing DIP and the technology of functionalization of a GaAs surface with antibod- ies against Escherichia coli and Legionella pneumophila bacteria. In the process of developing a semi-autonomous workstation for monitoring water reservoirs for the presence of E. coli and L. pneumophila, we also demonstrate specific detection of these bacteria in an aqueous environment at better than 103 CFU/mL. [1] S. Aithal et al., Photocorrosion metrology…, J. Phys. D: Appl. Phys., 50 (2017) 035106. [2] H. Sharma et al., pH-Dependent Photocorrosion…, J. Phys. Chem. C, 120 (2016) 26129-37. [3] S. Aithal, J.J. Dubowski, Open circuit potential monitored…, Appl Phys Lett, 112 (2018) 153102. [4] J.J. Dubowski et al., Photo-electrochemical sensing method…, Patent, US 10,001,480 B2 (2018).
T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2671
Configuration mixing investigation in germanium isotopes through measurement of E0 transition strengths
Authors: Carlotta Porzio1; A. B. Garnsworthy2; J. Henderson3; J. Smallcombe2; J. K. Smith4 Co-authors: Bhattacharjee S.S. 5; V. Bildstein 6; M. Bowry 2; Robin Coleman 6; I. Dillmann 2; Greg Hackman 5; Silvia Leoni 7; C. Natzke 8; B. Olaizola 2; E. E. Peters 9; C. E. Svensson 10; Steven Yates 9; T. Zidar 11
1 Università degli Studi di Milano, TRIUMF 2 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 3 LLNL 4 Reed College 5 TRIUMF 6 University of Guelph 7 Università degli Studi e INFN Milano (IT) 8 Colorado School of Mines 9 University Of Kentucky 10 Department of Physics, University of Guelph, Guelph, Ontario 11 Department of Physics, University of Guelph, Guelph, Ontario
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Experimental and theoretical studies of the germanium isotopes point increasingly toward exotic combinations of nuclear-structure effects, with indications of triaxiality, configuration mixing, and
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shape coexistence. A simple two-state mixing model has been used to describe 0+ states in the even- even 72,74,76Ge isotopes, and reasonable agreement with experimental data from Coulomb excitation measurements was found. More recent studies on 72Ge led to the conclusion that its low-spin struc- ture could be satisfactorily described via an admixture of two triaxial rotors. 76Ge is a promising candidate for the observation of neutrinoless double-beta decay, but theoretical models have not reached agreement on the value of the nuclear matrix element for the process. A proper experimental description of mixing is thus crucial to provide a benchmark for theoretical work and obtain an accurate knowledge of the wavefunctions of the initial and final states involved. Detailed spectroscopic studies of the 72,74,76,78Ge isotopes using the GRIFFIN spectrometer at TRIUMF- ISAC are in progress with the goal of clarifying the structure of these nuclei and providing constraints for neutrinoless double-beta decay nuclear matrix element calculations. The nature of low-lying configurations in the germanium isotopes are probed through measurements of the inter-band E0 transition strength, a highly sensitive experimental observable. Indeed, E0 transitions are still poorly studied along the germanium isotopic chain, and only one E0 strength is known among the isotopes under investigation. The present studies combine electron and γ-ray spectroscopy. Initial results will be presented from data collected for the decay of 72Ga to 72Ge.
W1-1 Degenerate Quantum Gases and Cold Atoms and Molecules (DAMOPC/DCMMP) |Gaz quantiques dégénérés, molécules et atomes froids (DPAMCP/DPMCM) / 2672
Quantum state dependent chemistry of ultra-cold 6Li2 dimers
Author: Erik Frieling1 Co-authors: Denis Uhland 2; Gene Polovy ; Kirk Madison 2
1 University of British Columbia 2 UBC
Corresponding Authors: [email protected], [email protected], [email protected]
Reactive and inelastic collisions of ultra-cold molecules has generally been observed to follow a universal rate law described by the quantum Langevin model. The salient feature of this law isan independence of the reaction probability from the short-range physics of the interaction. We report 6 on reactive and inelastic collisions of Li2 dimers in several ro-vibrational states of the a(13Σ+u ) potential. While the v = 0, 5, 8 are observed to decay at the universal limit, decay of the |v = 9, N = 0⟩ state exhibits a deviation from universality, opening up the possibility of using external magnetic fields to tune the reaction rate.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2673
54 - Quantum state dependent chemistry of ultra-cold 6Li2 dimers
Author: Erik Frieling1 Co-authors: Denis Uhland 2; Gene Polovy ; Kirk Madison 2
1 University of British Columbia 2 UBC
Corresponding Authors: [email protected], [email protected], [email protected]
Reactive and inelastic collisions of ultra-cold molecules has generally been observed to follow a universal rate law described by the quantum Langevin model. The salient feature of this law isan
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independence of the reaction probability from the short-range physics of the interaction. We report 6 on reactive and inelastic collisions of Li2 dimers in several ro-vibrational states of the a(13Σ+u ) potential. While the v = 0, 5, 8 are observed to decay at the universal limit, decay of the |v = 9, N = 0⟩ state exhibits a deviation from universality, opening up the possibility of using external magnetic fields to tune the reaction rate.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2674
39 - Sorting of Free-Space Spatial Modes of Light with Integrated Optics
Authors: Boris BravermanNone; Alexander SkerjancNone; Orad ReshefNone; Jeremy UphamNone; Robert W. BoydNone
Corresponding Author: [email protected]
Generating and sorting spatial modes of light is a recurring obstacle to using multiple transverse modes for both classical and quantum free-space optical communication. The Hermite-Gaussian (HG) modes provide a complete propagation-invariant set of basis states, but they cannot be trans- formed or sorted with common optical elements. Current implementations of free-space mode sort- ing thus suffer from limited efficiency, high losses, or complex experimental realization. In contrast, the manipulation of transverse modes in integrated optical waveguides is enabled by the inherently non-degenerate properties of these different modes and recent advances in nanophotonic fabrication. The similarity between the HG modes in free space and the transverse modes in a multi-mode (MM) rectangular waveguide allows for coupling between these two platforms using a simple microscope objective. Here, we extend previous work in on-chip manipulation of spatial modes of light in two ways. First, we couple the light in and out of the integrated device, which allows sorting of free-space modes. Second, we sort modes with non-zero transverse mode index in the vertical direction, forming a 2-D array of transverse modes. We sequentially outcouple the different transverse modes from the MM waveguide by evanescently coupling a series of single-mode (SM) waveguides with transverse dimensions tailored to resonance with a particular mode of the MM waveguide. Light in the reso- nant transverse mode is efficiently coupled to the SM waveguide, while the remainder of themodes continue propagating in the MM waveguide unaffected. This approach will enable fast, efficient, and complete control over the spatial structure of light both on-chip and in free space.
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2675
WITHDRAWN - Magnetometry for Gravitational Measurements of Antihydrogen with ALPHA-g
Authors: Nathan Evetts1; on behalf of the ALPHA CollaborationNone
1 University of British Columbia, Canada
Corresponding Author: [email protected]
The Einstein equivalence principle (EEP) has never been directly examined with an antimatter test body. To address this, the ALPHA Collaboration is constructing a new apparatus (ALPHA-g) which can test the EEP using magnetically trapped antihydrogen atoms. I will discuss motivations for these experiments, as well as the methods we intend to employ. In particular, magnetic field characteri- zation will be an essential component of the experimental methodology. The antiatom gravitational energy difference between the top and bottom of our trap is about a factorof 104 smaller than the magnetic confinement energies involved. This necessitates the use of precision magnetometers that
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will allow us to distinguish between the effects of magnetic and gravitational fields on antihydrogen trajectories. We will accomplish the required magnetometry using techniques drawn from the fields of nuclear magnetic resonance and non-neutral plasmas. I will overview these in the context of the greater experiment.
W2-1 Creative Education and Partnerships in Learning (DPE) | Éducation créative et partenar- iats d’apprentissage (DEP) / 2676
Ignite wonder, empower dreams, explode soda
Author: Sandra Eix1
1 Science World British Columbia
Corresponding Author: [email protected]
Science Centres have long been known for pyrotechnical demonstration shows, summer camps, and larger-than-life exhibits. But we are increasingly being recognized as key players in larger learning ecosystems that support STEM learners of all ages. I’ll show ways that Science World (and other in- formal science education organizations) collaborate with more formal institutions like universities, K-12 education systems, and industry to bring STEM learning to a wide audience, particularly to groups that are traditionally underserved. Warning: this presentation may involve audience partic- ipation and rubber chickens.
W2-1 Creative Education and Partnerships in Learning (DPE) | Éducation créative et partenar- iats d’apprentissage (DEP) / 2677
Teaching with Neutrons: Labs, Courses, and Student Research Projects at the McMaster Nuclear Reactor
Authors: Patrick Clancy1; Maikel Rheinstadter1; Bruce Gaulin1
1 McMaster University
Corresponding Authors: [email protected], [email protected], [email protected]
The McMaster Nuclear Reactor (MNR) is a 5 MW multipurpose research reactor, located oncampus at McMaster University in Hamilton, Ontario. As one of the three most powerful university-based reactors in North America, and the only major neutron source in Canada, the MNR offers unique opportunities for teaching and learning, especially for physicists. We are currently developing a series of undergraduate and graduate level demonstration experiments, which are primarily focused on neutron scattering techniques (i.e. the study of materials using neutron diffraction and neutron spectroscopy). These experiments are designed to either be incorporated as “stand-alone” additions to existing lab courses, or combined to form a short experimental techniques or special topics course. In this talk, we will describe the McMaster Alignment Diffractometer (MAD), our primary instru- ment for educational and teaching purposes. We will also present several examples and potential options for incorporating neutron scattering into your courses and student research projects.
T4-9 Quantum Theory (DTP) | Théorie quantique (DPT) / 2679
Dynamical tunnelling in the quantum kicked top
Author: Jack Davis1
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Co-authors: Robert Mann 2; Shohini Ghose 3
1 University of Toronto 2 University of Waterloo 3 Wilfrid Laurier University
Corresponding Authors: [email protected], [email protected], [email protected]
The quantum kicked top is a fundamental model used to study the emergence of classically chaotic behaviour in periodically driven systems arising from a quantum mechanical origin. Experimen- tally realized as a many-body ensemble of interacting qubits, the kicked top has allowed insight into how nonlinear features in the classical picture, such as a mixed phase space and bifurcation dy- namics, influence underlying quantum characteristics including entanglement generation, tunneling, and thermalization. This work explores the strictly quantum mechanical phenomenon of dynami- cal tunnelling of spin coherent states between classically stable regions of phase space separated by a chaotic sea. Using analytical and numerical methods we explore the non-trivial relationship between the frequency of dynamical tunneling and the amount of chaos present, even in the deep quantum regime. The connection to thermalization of an isolated system and its relevance for future experimental tests is discussed.
T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2680
Beta decay spectroscopy of Europium-160
Author: Daniel Yates1
Co-authors: Reiner Kruecken 2; Iris Dillmann 2
1 TRIUMF 2 TRIUMF
Corresponding Authors: [email protected], [email protected], [email protected]
Although the nuclear shell model does well to predict the structure of spherical nuclei, its ability to describe deformed nuclei far from shell closures is lacking. Models attempting to describe the structure of deformed nuclei, both from the microscopic and macroscopic perspective, require infor- mation on the excited energy levels of these nuclei in order to improve their predicting power. Incom- plete and disagreeing information on the beta decay scheme of 160Eu to 160Gd has been previously published [1,2], so a comprehensive picture of this decay is not yet available. Recently published data [3] improves the decay scheme, though there are still many unplaced levels and gamma-ray tran- sitions, and information on beta-feeding intensities is lacking. At TRIUMF-ISAC, 160Eu beta decay data was collected using the GRIFFIN (Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei) array of high-purity germanium detectors coupled with LaBr3 fast-timing detectors and a conversion electron spectrometer. Over 10 million decays were recorded, allowing a comprehensive analysis of the beta decay of 160Eu. New results from the ongoing analysis of this decay will be presented. [1] N. A. Morcos et al., J. Inorg. Nucl. Chem. 35, 3659 (1973). [2] J. M. D’Auria et al., Can. J. Phys. 51, 686 (1973). [3] D. Hartley et al., Phys Rev. Lett. 120, 182502 (2018).
W1-5 ”Bertram Brockhouse and the History of Canadian Neutron Scattering” (DHP) | ”Bertram Brockhouse et l’histoire de la diffusion de neutrons canadienne” (DHP) / 2681
Neutron Scattering at the McMaster Nuclear Reactor: Past, Present and Future
Page 149 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Authors: Bruce Gaulin1; Patrick Clancy1; John Greedan1
1 McMaster University
Corresponding Authors: [email protected], [email protected]
The McMaster Nuclear Reactor is a 5 MW nuclear reactor, which is now the only source ofneu- trons in Canada capable of supporting a neutron scattering program. In the past, its contributions to Canadian neutron beam science have been modest, largely due to the preeminent role played by in this area by the NRU reactor at the Chalk River Laboratories. Nonetheless, it has a distinguished history of contributions in both education and materials research. Bert Brockhouse and his stu- dents built one of the early triple axis spectrometers on beam port 6 after his arrival at McMaster in 1962, while Peter Egelstaff (Guelph) built and operated a liquids diffractometer on beamport5 at around the same time. John Greedan (McMaster) famously built and operated a neutron powder diffractometer which produced the first full chemical structure of the high temperature supercon- ductor YBa2Cu3O7 in the 1980s. Also, in the 1980s John Copley (McMaster, later NIST) built and operated a vertical, small angle neutron scattering instrument which was used to study nanostruc- ture in materials throughout the late 1980s and 1990s. These successes have set the stage for anew suite of neutron diffraction instruments put forward in the “Building a Future for Canadian Neutron Scattering” proposal currently being developed.
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2682
Potential mapping in GaN nanowire p-n junctions via off-axis electron holography
Author: Anitha Jose1 Co-authors: Karen L. Kavanagh 2; Sharif Sadaf 3; Haipeng Tang 3
1 Simon Fraser University 2 SFU 3 Advanced Electronics and Photonics, National Research Council Canada
Corresponding Authors: [email protected], [email protected]
GaN nanowires (NWs) have been applied in devices including light emitting diodes (LEDs) photode- tectors and laser diodes, but control of the dopant distribution has been a difficult task [1]. Also it is well known that polarization effects have an influence on device properties. A previous reporton GaN NWs found an effect of strain on the charge distribution via off-axis electron holography EH [2]. We report the measurement of the electric potential and depletion width in GaN NW p-n junc- tions using EH which is carried out using transmission electron microscopy (TEM) [3]. Nanowire p-n junctions grown by Molecular Beam Epitaxy, with Mg and Si as the p and n-type dopants, had doping concentration of 5 x 1017 and 1 x 1019 cm3, respec- tively, based on planar growth calibrations. A high density of basal plane (0001) stacking faults was found to be present within the p-type side whereas the n-side was free of detectable defects. Also the diameter of the p–type segment of the wires was always larger and highly anisotropic compared to the more uniform diameter n-type side. Phase images and potential profiles, extracted from the EH measurements, showed both an effect of thickness and the presence of a junction. An average built-in voltage of 0.5 ± 0.1 V and depletion width of 80 ± 5 nm were measured which both indicate either a smaller carrier activation or reverse biasing from charging or polarization effects. Results from a variety of growth conditions and structures will be presented. 1. Wallentin, J et al. Doping of semiconductor nanowires. J. Mater. Res. 26, 2142 (2011). 2. Chen, X et al. Controlling charges distribution at the surface of a single GaN nanowire by in-situ strain. Prog. Nat. Sci. Mater. Int. 27, 430–434 (2017). 3. Darbandi, A et al. Direct Measurement of the Electrical Abruptness of a Nanowire p–n Junction. Nano Lett. 16, 3982–3988 (2016).
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R1-2 Membrane Biophysics Joint Session Part I (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes I (DPMB/DPMCM/SBC) / 2683
Neutrons and X-Rays for Health and Disease
Author: Maikel Rheinstadter1
1 McMaster University
Corresponding Author: [email protected]
Molecular biology is key to understand the origin of diseases and the molecular mode-of-action of drugs, which is essential for modern drug design. Neutron and x-ray scattering are amongst our most advanced tools to study such molecular structure and dynamics. Together with computer sim- ulations they provide unprecedented capabilities in this respect. I will give examples of applications of neutrons and x-rays to better understand the functioning of drugs and antibiotics and howthese experiments shed new light on our understanding of cell membrane structure and dynamics, infec- tious diseases, human blood, and the origin of life, including biomedical applications [1]. [1] http://www.rheinstaedter.de/maikel/publications/publications.htm
W2-6 Local probes (DCMMP) | Sondes locales (DPMCM) / 2684
Imaging the In-Plane Anisotropy and Lattice Defects of ReS2 Us- ing Scanning Tunneling Microscopy
Authors: Ryan Plumadore1; Justin Boddison-Chouinard1; Florence Grenapin1; Ahmed Rezk1; Gregory Lopinski2; Adina Luican-Mayer1
1 University of Ottawa 2 National Research Council of Canada
Among the layered transition metal dichalcogenides, the compounds that exhibit in-plane anisotropy are of particular interest as they offer an additional tuning knob for their novel properties. Inthis talk we focus on studying the nanoscale lattice structure of semiconducting ReS2 by using an ultrahigh vacuum, room temperature scanning tunneling microscope. We demonstrate that rhenium atoms form diamond-shaped clusters, organized in disjointed chains. We employ scanning tunneling spectroscopy to measure the bandgap and positions of the valence and conduction bands. We further characterize the structure and properties of lattice defects in the anisotropic planes of ReS2 by exploring their influence on the local electrostatic environment.
T2-1 Soft Matter AM-2 (DCMMP) | Matière molle AM-2 (DPMCM) / 2685
Self-regulating mechanisms of bi-directional transport through the Nuclear Pore Complex
Author: Anton Zilman1
1 University of Toronto
Corresponding Author: [email protected]
Nuclear Pore Complex (NPC) is a biomolecular “nanomachine” that controls nucleocytoplasmic transport in eukaryotic cells. The key component of the functional architecture of the NPCisthe
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assembly of the polymer-like intrinsically disordered proteins that line its passageway and play a central role in the NPC transport mechanism. Due to paucity of experimental methods capable to directly probe the morphology and the dynamics of this assembly in intact NPCs, much of our knowledge about its properties derives from in vitro experiments interpreted through theoretical and computational modeling. Remarkably, despite their molecular complexity, much of the behavior of these assemblies and their selective permeability with respect to cargo-carrying transport proteins can be understood based on minimal complexity models relying on the statistical physics of molec- ular assemblies on the nanoscale. Due to the unstructured nature of the proteins in the NPC passageway, it does not possess a molec- ular “gate” that transitions from an open to a closed state during translocation of individual cargoes. Rather, its passageway simultaneously contains multiple transport proteins carrying different car- goes in both directions. Although this feature increases NPC throughput, it remains unclear how the NPC maintains selective and efficient bi-directional transport under such crowded conditions. Iwill present of a coarse-grained computational model of the NPC transport and will discuss various pro- posed solutions to the crowding problem in light of the model results and the available experimental data.
W2-5 Dark matter searches (PPD) | Recherche de matière sombre (PPD) / 2686
Calibration and Physics Outlook of PICO-40L
Author: Colin MooreNone
Corresponding Author: [email protected]
For the last decade, bubble chamber detectors have filled a niche in probing the spin-dependent dark matter parameter space, due to the use of fluorinated targets and the innate rejection ofelectron recoil events. Located at the SNOLAB underground facility, PICO-40L is the successor to the PICO- 60 experiment which produced world-leading WIMP-proton cross section limits, with final results reported earlier this year. The new detector employs an alternative “Right-Side-Up” design which is expected to eliminate backgrounds observed in previous. As of early summer 2019, PICO-40L is expected to be filled and collecting calibration data. The calibration strategy and preliminary results will be presented, along with the physics outlook.
M1-7 Identity and Physics Education (DPE/CEWIP) | Identité et enseignement de la physique (DEP/CEFEP) / 2687
Evaluation of a Science & Math Peer Tutoring Program
Authors: Sarah Johnson1; Stephan Struve2; Azadeh Akhtari-Zavareh1
1 Simon Fraser University 2 Carleton University
Corresponding Author: [email protected]
In 2014 the Physics Department at Simon Fraser University (SFU) began a peer tutoring program to support the students enrolled in our two “Physics for the Life Sciences” first-year courses. Four undergraduate students who earned high grades in these courses were recruited to be volunteer peer tutors and run weekly drop-in tutoring sessions. We specifically chose students majoring in the life sciences and/or planning to attend medical school so that they would be true peers tothe students in these courses. In 2016 this program was expanded to encompass three additional subject areas: Biology, Chemistry and Mathematics. In the same year with support from the SFU Institute for the Study of Teaching and Learning in the Disciplines, we conducted a study to determine the impact of this peer tutoring program on both the students being tutored (the tutees) and the tutors themselves. We administered surveys and conducted focus groups and interviews with both the tutors and the tutees in order to determine the influence their experiences with peer tutoring had
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in three arenas: enhanced learning, social experience and sense of agency. In addition we looked at the effect of peer tutoring on the academic performance of students who attended asignificant number of tutoring sessions. The results of these investigations will be presented. We will also discuss how this program continues to grow at SFU beyond its humble beginnings and our plans for the future.
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2688
Fabricating van der Waals heterostructures
Author: Justin Boddison-Chouinard1 Co-author: Adina Luican-Mayer 1
1 University of Ottawa
Corresponding Author: [email protected]
The isolation of single layer graphene in 2004 by Geim and Novoselov introduced a technique that researchers could extend to the broad family of van der Waals materials. Just as the van der Waals bonds responsible for holding together adjacent layers of two-dimensional (2D) materials can be broken, they can also be put back together. Crystals can then be reassembled with layers from dif- ferent compounds or in different stacking orientations to create new materials previously inexistent in nature. In this work, we describe a home-built transfer setup that allows the user to create these new crystals (van der Waals heterostructures) by stacking distinct layered 2D materials with lat- eral alignment and, importantly, angular alignment. In addition to presenting the transfer set-up, we also describe some techniques for preparing the crystals that are subsequently stacked. Finally, characterization of the heterostructures is presented.
R2-7 Nuclear Structure IV (DNP) | Structure nucléaire IV (DPN) / 2689
High Precision Mass Spectrometry for Fundamental Tests of the Weak Interaction
Author: Erich Leistenschneider1
1 TRIUMF
Corresponding Author: [email protected]
Nuclear decays are windows to test the validity of predictions of the Standard Model. In special, nuclear β-decay data of superallowed 0+→0+ transitions has provided crucial experimental input to tests of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix. These studies require precise understanding of properties of these special transitions, such as half-life, branching ratios and transition energies (or Q-values). For the latter, high-precision mass spectrometry plays an important role. The Q-values of these decays, which are essentially mass differences betweenthe initial and final states, are key ingredients of the most precise evaluations of up-down element (Vud) of the CKM matrix. These measurements are challenging: they require relative mass uncertainties on the order of a few parts per billion. Nowadays, this level of precision can only be attained using Penning Trap Mass Spectrometry (PTMS). Such studies are pursued at the TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) facility in Vancouver. In this talk, I will address TITAN’s most recent contributions to fundamental tests of the weak interaction, including the recent measurement of the Q-value of the 22Mg→22Na su- perallowed β+ decay. I will also cover our efforts to pursue the measurement of the Q-value ofthe 74Rb→74Kr superallowed decay. This case has the highest atomic number among all studied cases
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and is particularly challenging given its low half-life (~65 ms). However, TITAN is uniquely situated to perform this measurement. It can perform PTMS of radioactive species using Highly Charged Ions (HCI), which permits a significant increase in precision comparing to conventional PTMS. Onthe other hand, employing HCI demands strict vacuum requirements in the mass spectrometer in order to prevent electron recombination. For that, a new cryogenic vacuum system is being integrated to the Penning trap.
R1-2 Membrane Biophysics Joint Session Part I (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes I (DPMB/DPMCM/SBC) / 2690
Proteins drilling holes in lipid membranes: The influence of the membrane physical parameters
Author: Cécile Fradin1
Co-authors: Markus Rose 1; Ahmad Mahmood 1; Helen Zhu 1
1 McMaster University
Corresponding Authors: [email protected], [email protected], [email protected], mah- [email protected]
The elimination of unwanted cells is essential to the survival of all living organisms. Thisprocess is under the control of a set of proteins called Bcl-2 family proteins, several of which cooperate to permeabilize the outer membrane of mitochondria, sentencing the cell to death. Using reconstituted membrane systems to which we add fluorescently labelled Bcl-2 family proteins (both an activating protein, Bid, and a pore forming protein, Bax), we investigate the regulation of the pore formation process by both lipids and protein-protein interactions. Using liposomes with varying lipid composi- tions, we studied the influence of the physical properties of the membrane (surface charge, thickness, order parameter, spontaneous curvature) on the different steps of the Bax pore formation pathway. We found that surface charge influences the initial recruitment of Bid to the membrane, while lipid tail disorder helps the insertion of both Bid and Bax into the membrane. In addition, using a planar supported lipid bilayer and confocal imaging, we quantified the association of these two proteins directly in the membrane. Our work highlights the different layers of control that can be used by cells to regulate cell death.
T2-10 Nuclear Instrumentation (DNP) | Instrumentation nucléaire (DPN) / 2691
Implementing an ancillary detector for DESCANT to determine neutron energies
Author: Harris Bidaman1
Co-authors: Allison Radich 2; P. E. Garrett 3; V. Bildstein 1
1 University of Guelph 2 university of Guelph 3 Department of Physics, University of Guelph, Guelph, Ontario
Corresponding Authors: [email protected], [email protected], [email protected]
The study of neutron rich nuclei far from the valley of stability has become an increasingly impor- tant field of research. One of the decay mechanisms that opens when the decay Q value becomes sufficiently large is that of β-delayed neutron emission and the probability of its occurance, Pn, is important when studying the astrophysical r-process [1]. β-delayed neutron spectroscopy can also provide structural information being sensitive to the angular momentum in the process and the final
Page 154 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
state wave functions. The utilization of large scale neutron detector arrays in future experiments is imperative for these kinds of studies. One of such array is DESCANT (DEuterated Scintillator Array for Neutron Tagging) [2], designed to be coupled with the large-scale gamma spectrometers GRIF- FIN [3] and TIGRESS [4] at the TRIUMF-ISAC and ISACII facilities, allowing for the study of both beta decay and reaction experiments, respectively.
The initial design of DESCANT was for the intended use as a neutron-tagging detector forfusion evaporation reactions [2] and thus obtaining precision on the neutron energy was not considered a priority. This limitation could be overcome through the use of thin plastic scintillators positionin front of the DESCANT detectors. The energy of the neutrons can then be determined via the timeof flight technique, similar to that implemented in the VANDLE array [5]. To investigate the viability of this augmentation, GEANT4 will be used to simulate and optimize the experimental design. A series of tests will also be performed using a single DESCANT detector and a plastic scintillator to verify the improvement in performance. The progress of both the simulations and the tests using the DESCANT detector will be discussed. [1] Mumpower, M. et al. Prog Part Nucl Phys 86, 86 (2016). [2] Garrett, P.E., et al. Hyperfine Interact (2014) 225: 137. [3] Svensson, C.E., Garnsworthy, A.B. Hyperfine Interact (2014) 225:127-132. [4] Svensson, C.E. et al. J. Phys. G: Nucl. Part. Phys. 31 S1663. [5] Peters, W.A., et al. Nucl Instrum Methods Phys Res A 836 (2016) 122–133.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2692
WITHDRAWN - Laser spectroscopy of the g6Φ − X4∆ electronic transition of iron monodeuteride, FeD
Author: Ryan Harvey1
Co-authors: Dennis Tokaryk 2; Allan Adam 1
1 University of New Brunswick 2 Dept. of Physics, University of New Brunswick
Corresponding Authors: [email protected], [email protected], [email protected]
Transitions of the gas-phase iron hydride molecule are observed in the spectrum of the sun and of some cooler stars. It has a strong magnetic response, and the Zeeman splitting of individual rotational lines is used to determine the strength of the magnetic field produced by the stars in which its signature is seen. Its spectrum is complicated by the high spin and angular momentum of its electronic states, and there are many gaps in the experimental observations of this molecule. Further, information regarding its isotopolgues is scant. We will describe our recent experiments on the iron monodeuteride (FeD) isotopologue, focusing on the intercombination band g6Φ−X4∆ near 448 nm. We create the molecule in a pulsed supersonic jet of helium seeded with both iron pentacarbonyl, Fe(CO)5, and molecular deuterium. The jet pulse is electrically discharged as it expands fromthe high-pressure (40 psi) plenum into vacuum, creating the FeD molecule, which is detected with laser- induced fluorescence. The results inform the electronic structure of the FeH family of molecules, and permit indirect estimation of vibrational spacings in the upper state.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2693
WITHDRAWN - Identification of the A1Π and a3Π electronic states of magnesium monosulphide, MgS
Page 155 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Bradley Guislain1
Co-authors: Dennis Tokaryk 2; Nicholas Caron 1; Allan Adam 1
1 University of New Brunswick 2 Dept. of Physics, University of New Brunswick
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Magnesium and sulphur are the 9th and 10th most abundant elements in our galaxy, and a compound in solid form (niningerite) has been found in meteors. Its gas-phase compounds are therefore candi- dates for detection in stellar atmospheres, as have been the magnesium-bearing compounds MgNC and MgCN. The simplest combination of these elements, MgS, is a gas-phase radical that untilre- cently had been characterized only in its ground state X1Σ+ via microwave- and millimetre-wave spectroscopy, and through the B1Σ+ − X1Σ+ electronic transition near 434 nm. In some recent experiments, we have created MgS by producing gas-phase magnesium in a Broida oven, exciting the atoms with activated nitrogen, and reacting these with CS2. This has permitted us to excite indi- vidual rotational levels of the B1Σ+ state with a cw laser beam and to observe the fluorescence from them. We will report on the analysis of this fluorescence, which has allowed us to locate the two low- est excited states of MgS, A1Π and a3Π, and to determine their rotational structure for comparison with calculations.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2694
79 - WITHDRAWN - First Implementation of CsI(Tl) Pulse Shape Discrimination at a B-Factory Experiment for Improving Hadronic vs Electromagnetic Shower Identification
Authors: Savino Longo1; Michael Roney1
1 University of Victoria
Corresponding Authors: [email protected], [email protected]
This talk presents a novel new method for identifying electromagnetic vs. hadronic showers inthe Belle II electromagnetic calorimeter though the first implementation of CsI(Tl) pulse shape discrim- ination (PSD) at a B-factory experiment. During the first run of collision data-taking of the Belle II experiment in summer 2018, the 8736 CsI(Tl) crystals in the Belle II calorimeter were instrumented with electronics allowing for online CsI(Tl) waveform digitization and readout. We show that by analyzing the pulse shapes of the waveforms recorded in this collision data run, PSD allows for calorimeter clusters produced by hadronic interactions to be distinguished from electromagnetic showers. This experimental technique takes advantage of the ionization dE/dx dependent CsI(Tl) scintillation response allowing for hadronic showers that contain energy deposits from highly ion- izing secondary particles such as protons and alpha particles to be separated from electromagnetic showers. To utilize this information for improving particle identification at Belle II, a Boosted Deci- sion Tree multivariate classifier is trained to identity hadronic and electromagnetic showers based on types of CsI(Tl) pulse shapes present in the crystals associated with the calorimeter cluster. Using 0 control samples of photon’s and KL’s isolated from Belle II collision data, the ability to select neutral hadronic showers with high efficiency and low photon backgrounds is demonstrated and compared with shower shape methods employed at past B-Factory experiments.
M1-5 Nuclear Astrophysics (DNP) | Astrophysique nucléaire (DPN) / 2695
Modern-day precision mass measurements and the astrophysical r process
Page 156 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Rodney Orford1
1 Lawrence Berkeley National Laboratory
The challenge of identifying the astrophysical site(s) of the rapid neutron capture (r) process, which is responsible for the creation of half of the heavy elements found today, is a multifaceted one which requires input from a gamut of disciplines including observation, theory, and experiment. More ex- perimental data, particularly of nuclear masses, on the neutron-rich side of stability is needed to alleviate uncertainties in current r-process calculations. The Canadian Penning Trap (CPT) mass spectrometer is situated at Argonne National Laboratory in the CARIBU facility where intense beams of neutron-rich nuclei are created from the spontaneous fission of a 252Cf source. To take advantage of the unique beams available at CARIBU, an upgrade to a phase-imaging mass measurement tech- nique (PI-ICR) has been completed at the CPT. This modern technique offers several benefits which cumulatively increase the experimental sensitivity of the CPT, enabling mass measurements of nu- clei further from stability than was previously possible. I will describe the implementation of PI-ICR at the CPT and highlight recent mass measurements of rare-earth nuclei near N = 100 which may be used to impose constraints on the astrophysical site of the r process.
T4-1 Soft Matter PM-2 (DCMMP) | Matière molle PM-2 (DPMCM) / 2696
Anomalous, caged and obstructed diffusion as seen through the lens of inverted variable-lengthscale fluorescence correlation spec- troscopy
Author: Cécile Fradin1
Co-author: Michael Stolle 1
1 McMaster University
Corresponding Authors: [email protected], [email protected]
The diffusion of macromolecules in cells and in complex fluids is often found to deviate fromsim- ple Fickian diffusion, and to have a strong dependence on lengthscale. Yet protein diffusion mea- surements usually only probe a narrow range of lengthscales. To circumvent this issue, we use variable-lengthscale fluorescence correlation spectroscopy (VLS-FCS), where the size of the volume of observation is varied over several orders of magnitude. We combine it with a numerical inversion of the data allowing to retrieve the mean-squared displacement of the process over over up to five decades in time. We performed computer simulations to examine the signature of several biologi- cally relevant diffusion processes (simple diffusion, continuous-time random walk, caged diffusion, obstructed diffusion, two-state diffusion and diffusing diffusivity) in inverted VLS-FCS. Wecompare the results of our simulations to the diffusion of probes in gels and crowded polymer solutions. Al- though in both cases the diffusion is anomalous, it has astonishingly different characteristics inthese two systems. Our work shows that even for noisy diffusion processes such as the ones encountered in cells, an unbiased discrimination between different classes of diffusion models is possible.
M1-1 Test of Fundamental Physics with Atoms (DAMOPC) | Tests de physique fondamentale avec des atomes (DPAMPC) / 2697
Advances in Microwave Spectroscopy of Antihydrogen
Author: Justine Munich1
Co-author: ALPHA Collaboration
1 Simon Fraser University, Canada
Page 157 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
The hydrogen ground state hyperfine splitting is known to seven parts in 1013 [1].The Antihydrogen Laser Physics Apparatus (ALPHA) Collaboration seeks to perform precision tests of symmetries between matter and antimatter by measuring properties of antihydrogen and comparing them to its matter counterpart, hydrogen. This pursuit leads us to probe the ground state hyperfine splitting in antihydrogen; if charge parity time (CPT) symmetry holds then it should be identicalto that of hydrogen. We measure two positron spin resonance (PSR) frequencies in the same magnetic field, from which we extract the hyperfine splitting. In 2017, we reported a 200-fold improvement in the precision to which the hyperfine splitting had been measured in antihydrogen, resolving the frequency to four parts in 104 [2]. I will describe methods that have enabled us to further increase the precision to which we are able to measure this quantity by a substantial margin. I will also discuss implications of these new methods for matter/antimatter comparisons in precision tests of fundamental symmetries. [1] Petit, P., Desaintfuscien, M. & Audoin, C. Temperature dependence of the hydrogen maser wall shift in the temperature range 295–395 K. Metrologia 16, 7–14 (1980). [2] Ahmadi, M., et al. Observation of the hyperfine spectrum of antihydrogen. Nature 548, 66 – 69 (2017).
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2698
55 - Development of a Novel 650 MHz Resonator for Microwave Spectroscopy of Antihydrogen
Author: Justine Munich1 Co-author: ALPHA Collaboration
1 Simon Fraser University, Canada
Corresponding Author: [email protected]
The Antihydrogen Laser Physics Apparatus (ALPHA) Collaboration seeks to measure properties of antihydrogen and compare them to its matter counterpart, hydrogen, to perform precision tests of symmetries between matter and antimatter. Comparisons of hyperfine transition frequencies in positronic ground state antihydrogen with hydrogen provide an opportunity to test fundamental symmetries such as charge parity time (CPT) symmetry. The 1 T field in which we confine thean- tiatoms and perform spectroscopy is high enough that transitions between hyperfine levels amount to either a positron spin flip or an antiproton spin flip. Positron spin resonance (PSR) transitions occur around 30 GHz in 1 T and have been investigated previously [1, 2]. Anti-atoms trapped in the vicinity of a magnetic minimum undergo a PSR transition, causing them to be ejected and resulting in an annihilation event. Nuclear magnetic resonance (NMR) transitions are more challenging, and have not yet been studied: an antiproton spin flip simply converts an antihydrogen atom inone trapped state to another. A local maximum in the NMR frequency between trapped states occurs in the vicinity of 0.65 T, at 650 MHz. This provides an opportunity to make a measurement that is first order independent of magnetic field. However, the free space wavelength of radiation at this frequency, 46 cm, presents a challenge. It will not propagate down the 4 cm diameter Penning trap in which our experiments are performed. I will describe a novel structure that will simultaneously act as a Penning trap electrode and as a 650 MHz resonator capable of producing the microwave magnetic fields needed for an antihydro- gen spectroscopy experiment. This device is subject to severe design constraints. From a geometric perspective it is required to be a 2-cm long, 4-cm diameter tube, with 1 mm thick walls. From an electrostatic perspective it must act like a conducting Penning trap electrode with a high degree
Page 158 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
of cylindrical symmetry. And from an electrodynamic perspective it must support a highly sta- ble and precisely tuned mode at 650 MHz that generates a transverse oscillating magnetic field on axis. [1] Amole, C. et al. Resonant quantum transitions in trapped antihydrogen atoms. Nature 483, 439–443 (2012). [2] Ahmadi, M., et al. Observation of the hyperfine spectrum of antihydrogen. Nature 548, 66 – 69 (2017).
W1-11 Neutrinoless Double Beta Decay (DNP/PPD) | Double désintégration bêta sans neutrino (DPN/PPD) / 2699
EXO-200 Results
Author: Caio Licciardi1
1 Laurentian University
Corresponding Author: [email protected]
The EXO-200 Collaboration is searching for neutrinoless double beta decay (0vBB) using aliquid xenon time projection chamber, enriched in 136Xe. EXO-200 successfully finished two phases of data taking in December 2018. Now the collaboration is working towards a 0vBB search using the complete data set, with better energy resolution and increased discrimination of backgrounds, that is expected to significantly exceed the last sensitivity value of 3.7×10^25 yr for its half-life at90% CL. This talk will present the most recent EXO-200 results
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2700
Assembly and Characterization of MoS2/HBN heterostructures for Opto-electronic devices
Author: Kurt Tyson1
Co-authors: Kate Fenwick 1; Thomas Faour 1; James Fraser 1; Robert Knobel 1
1 Queen’s University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
2D transition-metal dichalcogenides (TMDs) exhibit unique optical and electronic properties that make them highly appealing to the scientific community. Like graphene, they have strong in-plane bonds and weak out-of-plane bonds, allowing for easy fabrication of complex single layer structures or molecular heterostructures. In particular, MoS2 is a TMD semiconductor that displays emerging photoluminescence (PL) through its transition from exhibiting an indirect bandgap in its bulk form to a direct bandgap at few- to monolayer thickness. Although it holds great potential for use in novel nanoelectronics and optical devices, there is still much variability in the reported PL and electron mobility across studies involving 2D MoS2. This necessitates a better understanding of its excitonic properties. In this work, we report on our exfoliation and membrane transfer technique: a modified mask aligner and dry PDMS transfer for assembly of heterostructures. We developed simple opti- cal methods to quantify layer number, which we compare with Raman spectroscopy, Atomic force microscopy, and PL spectrum analysis. We then compared the PL spectrum between layer number, h-BN encapsulated samples, and exfoliated vs. grown MoS2 via chemical vapour deposition (CVD). We found red shifted PL peaks with increasing layer number and in CVD-grown MoS2, indicative of crystal purity or structural differences for exfoliated devices. Also, PL intensity increased with
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decreasing layer number as well as with h-BN encapsulation. We further discuss the lithographic process used to integrate monolayer samples into a bottom-gated field effect transistor, followed by preliminary data.
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2701
Active dopant and associated diffusion potential mapping in Sil- icon nanowires
Authors: Cristina Cordoba1; Taylor Teitsworth2; James CahoonNone; Karen Kavanagh3
1 Simon Fraser University 2 PhD. student 3 SFU
Corresponding Authors: [email protected], [email protected]
Silicon nanowires (SiNWs) are attractive for a variety of applications such as photoelectrochemical (PEC) devices for hydrogen fuel production which require precise compositional and morphological control for abrupt electrical interfaces. However, SiNWs grown by the vapour-solid-liquid method typically encounters problems such as nonselective deposition on sidewalls, catalyst-induced com- positional gradients, inadvertent kinking and inhomogeneous doping. The bandgap of Si is 1.1 V, therefore multiple Si tunnel junctions are required for the operating voltage to exceed values re- quired to split water (1.23 V).Tunnel junctions require degenerate-doping conditions such that the field in the depletion region is strong enough to induce tunnelling, with a sharp potential profileto increase its probability. Trap-assisted tunnelling in Si via gold impurity levels usually outnumbers band-to-band tunnelling at low field strength, therefore a very small concentration of gold impuri- ties is believed to aid the tunnelling process. To this end electron holography (EH) combined with scanning TEM serve a critical role being able to non-invasively measure depletion region widths and their associated built-in voltages [1]. Although doping control has been demonstrated in VLS growth for SiNWs [2], growth of degenerate p-type Si, Boron (B) doped, has been challenging. Lower p-type doping is reached compared to n-type doping (Phosphorous) under the same conditions. We overcome these challenges synthesizing these structures by in situ chlorination of the NW surface with hydrochloric acid at temperatures ranging from 500 to 700 ℃. We demonstrate degenerately doped p/n and n/p sections with abrupt potential profiles of 1.1±1 V in SiNWs and depletion region widths as narrow as 10 ± 1 nm via EH. The results presented herein enable the growth of complex, degenerately-doped p-n junction nanostructures and are an essential step in the fabrication of PEC devices. [1] A. Darbandi, J. C. McNeil,A. Akhtari-Zavareh, S. P. Watkings, K. L. Kavanagh, Nano Letters 16 (2016). [2] D. J. Hill, T. S. Teitsworth, E. T. Ritchie, J. M. Atkin, J. F. Cahoon, ACS Nano 12 (2018). ———-.
T4-7 Optical Spectroscopy and control (DAMOPC) | Spectroscopie optique et contrôle (DPAMPC) / 2702
Tracking the Phase Transition in VO2 using High Harmonic Spec- troscopy
Author: François Légaré1
1 INRS
Page 160 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
We present a study that uses a technique extending upon high harmonic spectroscopy, which is gen- erated as a function of photoexcitation pump fluence to probe the resulting ultrafast dynamics of the insulator-to-metal phase transition in VO2 [1]. When heated to above ~343 K, VO2 experience a complete atomic rearrangement of the crystal lattice structure from a monoclinic insulator (M1 phase) to a metallic rutile crystalline structure (R phase). When initiating this IMT via photoexcita- tion, the pathways are even more complex. After photoexcitation, the ultrashort pulse immediately excited electrons creating the M1 state. With sufficient pump energy, the periodic lattice ofthe M1 phase can transition completely into the R phase. If there is insufficient energy, after a few hundred femtoseconds, the excited photodoped electrons in the M1 state relax into a pseudothermal state in which the thermalized photodoped populations have the same chemical potential (M1,b state). After about a picosecond, the M1,b state then transitions into a long-lived metastable monoclinic metallic M state. If the pumping fluence is between these two thresholds, a final metallic mixed state ofrutile and monoclinic is produced (R + M). So far, only Morrison et al. have reported the existence of the monoclinic metallic M state [2]. Here, we show that the IMT dynamics in VO2 can be tracked by measuring the yield of the 5th intraband harmonic. The temporal evolution of the harmonic yield reveals both time scales, i.e. ~300fs to reach the pseudothermal state and ~1.5ps for the mononiclinic metallic state. [1] M.R. Bionta et al., “Tracking ultrafast solid-state dynamics using high harmonic spectroscopy,” under review (2018). [2] V.R. Morrison et al., “A photoinduced metal-like phase of monoclinic VO2 revealed by ultrafast electron diffraction,” Science 346, 455 (2014). [3] M.R. Bionta et al., “Probing the phase transition in VO2 using few-cycle 1.8 μm pulses,” Phys. Rev. B 97, 125126 (2018).
M1-1 Test of Fundamental Physics with Atoms (DAMOPC) | Tests de physique fondamentale avec des atomes (DPAMPC) / 2703
A measurement of the Lamb shift in atomic hydrogen and its im- plication for the proton size puzzle
Author: Eric A. Hessels1
1 York University
Corresponding Author: [email protected]
We have measured the n=2 Lamb shift in atomic hydrogen. The measurement uses a direct mi- crowave transition between the 2S and 2P states, and employs the new frequency-offset separated- oscillatory-fields (FOSOF) technique. The FOSOF technique is a variation of the Ramsey separated- oscillatory field technique in which the two separated fields have their frequencies slightly off- set from each other. Our Lamb shift measurement, along with existing high-precision quantum- electrodynamics theory, leads to a precise measurement of the rms proton charge radius, and there- fore helps to resolve the eight-year-old puzzle created by contradictory determinations of the pro- ton size. In particular, this measurement is the direct analog of the very precise 2S-2P muonic- hydrogen determination of the proton size. Our recent work in determining the helium 23P fine structure and our new program to determine the electron electric dipole moment will also be dis- cussed briefly.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2704
56 - Ultrahigh-Precision Measurement of the n = 2 Triplet P Fine Structure of Atomic Helium Using Frequency-Offset Separated
Page 161 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Oscillatory Fields
Authors: K. Kato1; T. D. G. Skinner1; E. A. Hessels1
1 York University
Corresponding Author: [email protected]
For decades, improved theory and experiment of the n=2 3P fine structure of helium have allowed for increasingly precise tests of quantum electrodynamics, determinations of the fine-structure con- stant α, and limitations on possible beyond-the-standard-model physics. Here we use the new 3 3 frequency-offset separated-oscillatory-fields technique to measure the2 P2→2 P1 interval. Our result of 2 291176590(25) Hz represents a major step forward in precision for helium fine-structure measurements.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2705
65 - Low Background Measurement Capabilities At SNOLAB
Author: Ian Lawson1
1 SNOLAB
Corresponding Author: [email protected]
Experiments currently searching for dark matter and studying properties of neutrinos require very low levels of radioactive backgrounds both in their own construction materials and in the surround- ing environment. These low background levels are required so that the current and next generation experiments can achieve the required sensitivities for their searches. SNOLAB has several facilities which are used to directly measure these radioactive backgrounds. This presentation will describe the low background measurement facilities currently operating at SNOLAB, describe the data analy- sis techniques used and present results from these detectors. In addition, plans and options to expand these facilities to allow for the increased sensitivity required by the next generation of experiments will be described.
M2-2 Fundamental Symmetries (DNP) | Symétries fondamentales (DPN) / 2707
Towards measuring atomic parity violation effects in francium
Author: Mukut Ranjan Kalita1
1 TRIUMF
Corresponding Author: [email protected]
Measurements of parity violation effects in atomic systems test the Standard Model at lowener- gies and probe nucleon-nucleon interaction. Francium is a good system for atomic parity violation (APV) studies, because APV effects are predicted to be large in francium and its atomic structure is favourable for theoretical calculations. We are developing experiments to study APV effects in neutral francium atoms at the ISAC radioactive beam facility at TRIUMF. We use techniques of laser cooling and trapping to prepare the atoms for our measurements. Our current effort is based on optical spectroscopy of the electric dipole forbidden 7s-8s atomic transition aiming at the test of
Page 162 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
the strength of the electron-quark weak neutral coupling. In this talk, I will present our recent ob- servation of the Stark (electric field) induced 7s-8s transition and our roadmap towards observing APV. Operational funding by NSERC, NRC/TRIUMF, infrastructure support by DOE and NRC/TRIUMF, student support by U. of Manitoba, and travel support by CONACYT and Fullbright.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2708
46 - EDM3: Measuring the electron electric dipole moment using polar molecules embedded in solid argon
Authors: E. A. Hessels1; A. C. Vutha2; J. T. Singh3; M. C. George1; M. Horbatsch1; C. H. Storry1; G. Koyanagi1; A. Marsman1; R. Fournier1; A. Ragyanszki1; Z. Corriveau1; J. Perez-Garcia1; F. Fang3; N. McCall1; Yau H.1; K. Saltoun1
1 York University 2 University of Toronto 3 Michigan State University
Improved measurements of the electron electric dipole moment (eEDM) will strongly constrain the parameter space of new physics theories. Over the last decade, polar molecules have become es- tablished as the most promising systems for eEDM searches, due to the large internal electric fields experienced by an eEDM in these molecules. The sensitivity of eEDM searches is determined bythe coherence time available for measuring eEDM-induced electron spin precession, as well as the total number of molecules available over the course of a measurement. We present a new method, which combines long coherence times and large molecule numbers, for an eEDM search experiment with significantly improved precision. Our system, involving BaF molecules oriented within a solid argon matrix, also offers an array of reversals and controls for cleanly suppressing systematic effects toa level commensurate with the improved statistical precision.
T2-10 Nuclear Instrumentation (DNP) | Instrumentation nucléaire (DPN) / 2709
Commissioning of a Plasma Ion Source Using Monte Carlo Opti- misation Methods
Author: Jake Flowerdew1
Co-authors: Ish Mukul 2; Anna Kwiatkowski 2; Jens Dilling 3; Michael Wieser 1; Robert Thompson 4
1 University of Calgary 2 TRIUMF 3 triumf/UBC 4 University of Calgary, Canada
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
The controlled collimation of ion beams is of paramount importance in particle accelerators, high energy beamlines, and detector systems, as it determines the sensitivity and resolution of the instru- ments. This is especially the case when dealing with radioactive ion beams, where high transporta- tion yields are crucial due to the short lifetimes of certain nuclei. For this reason, it is essential to model the beam dynamics in order to optimise properties such as transmission and energy spread
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before the commissioning of new instruments. A plasma ion source (PIS), comprised of a heated fila- ment followed by an anode, Einzel lens and X-Y correction steerers, was modelled and Monte Carlo simulations were run using SIMION. The simulations also included the integration of this beam into the existing beamline of TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN). Optimising the voltage configurations in these simulations has proved successful in the commissioning ofthe PIS at the TITAN experiment, which will provide a versatile ion source, capable of delivering stable isotopes from gas and solid samples. The PIS will be able to deliver important calibration beam toTI- TAN’s experiments and will also enable off-line, high precision isotope composition measurements with the Multiple-Reflection Time-Of-Flight Mass Spectrometer (MR-TOF MS).
M2-3 Particles deep underground (PPD) | Particules profondément sous terre (PPD) / 2710
Continuing Prospects of the SNO+ Calibration Program
Author: Ryan Bayes1
1 Laurentian University
Corresponding Author: [email protected]
Neutrino physics continues to be a rich and vibrant field. SNO+, situated as it is in the Vale Creighton Mine at 6800 m water equivalent depth, promises to address a number of topics within the subject. To understand the measurements taken by the SNO+ detector, a similarly multifaceted approach is required for its calibration. The different techniques used in the SNO+ calibration will be described here with special focus on the transition from the SNO prototyped water phase calibration mea- surements to the calibration of the scintillator filled detector. With the heightened requirements for background suppression in SNO+, new materials have been chosen for the construction of the calibration systems. The opportunity has also been taken to design new calibration sources withbet- ter characteristics for the new target medium. Early results from newly commissioned calibration systems will be presented in contrast to the old systems with the future prospects for the scintillator calibration program.
T3-7 Frontiers in optics (DAMOPC) | Frontières en optique (DPAMPC) / 2711
Rayleigh Scattering Formulation of the Tune-out Wavelength: The- ory and Application to Metastable Helium
Authors: Gordon Drake1; Jacob Manalo1
1 University of Windsor
Corresponding Authors: [email protected], [email protected]
The tune-out wavelength is usually viewed a zero in the frequency-dependent polarizability [1,2]. This view is appropriate for an atom in an optical lattice that is fixed in space. However, foranatom interacting with a traveling plane wave from a laser, it is more appropriate to view the tune-out wavelength as a zero in the Rayleigh scattering cross section for coherent scattering. In lowest order, the two approaches are equivalent, but not when higher-order retardation corrections are taken into account. This paper presents a development of the theory, starting from the relativistic scattering matrix of QED to obtain a formulation of the problem in the velocity gauge [3]. Gauge invariance is discussed, and an equivalent length form is obtained for the leading retardation correction for S- states. The xpz retardation correction to the tune-out wavelength of helium near 304 nm is calculated to be 0.000 560 0236 nm. [1] B. M. Henson et al., Phys. Rev. Lett. 115, 043004 (2015). [2] Y.-H. Zhang et al., Phys. Rev. A 93, 052516 (2016). [3] G. W. F. Drake, J. Manalo and P.-P. Zhang, Hyperfine Int. submitted (2019).
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R2-10 Neutrinos and more (PPD) | Neutrinos et davantage (PPD) / 2712
Machine learning techniques for event reconstruction in water Cherenkov detectors
Author: Nick Prouse1
1 TRIUMF
Corresponding Author: [email protected]
Machine learning has the potential to enhance the sensitivities of water Cherenkov detectors by improving the event reconstruction to suppress backgrounds and systematic uncertainties. Such im- provements will be vital in achieving the precision measurements that current and next-generation water Cherenkov detectors are now aiming to perform. This talk covers several areas where machine learning is being explored for event reconstruction in the Super-Kamiokande and Hyper-Kamiokande projects. Specific physics motivations are discussed, including applications to neutrino oscillation and astrophysical neutrino measurements, followed by an overview of the plans, progress, and challenges of ongoing efforts to use machine learning techniques in these areas.
T3-2 Novel Magnetic Fusion Configurations (DPP) | Nouvelles configurations de fusion mag- nétique (DPP) / 2713
Developments in Compression of Magnetized Plasmas
Authors: Michel Laberge1; Michael Donaldson1; Michael Delage1
1 General Fusion
Corresponding Author: [email protected]
Magnetized Target Fusion (MTF) involves compressing an initial magnetically confined plasma on a timescale faster than the thermal confinement time of the plasma. If near adiabatic compression is achieved, volumetric compression of 350X or more of a 500 eV target plasma would achieve a final plasma temperature exceeding 10 keV. Power plant relevant fusion gains could be achieved provided the compressed plasma has sufficient density and dwell time. General Fusion is developing a compression system using pneumatic pistons to collapse a cavity formed in liquid metal containing a magnetized plasma target. This approach offers a low-cost driver, straightforward heat extraction, good tritium breeding ratio and excellent neutron protec- tion in power plant designs. Through an active plasma and compression R&D program, General Fusion is conducting fullscale and reduced scale plasma experiments and simulation of both. Although pneumatic driven compres- sion of full scale plasmas is the end goal, present compression studies use reduced scale plasmas and chemically accelerated aluminum liners. We will review results from our plasma target development and dynamic compression program. In particular we will focus on the two most recent tests in which we have detected significant increases in fusion neutron rates.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2714
Study of the 28Mg(t,30Mg)p reaction to investigate nuclear shell evolution at the boundary of the N=20 Island of Inversion
Author: T. Zidar1
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1 Department of Physics, University of Guelph, Guelph, Ontario
T. Zidar1, D. Mücher1, T. Kröll2, C. Berner3, V. Bildstein1, C. Burbage1, L. Atar1, L. Gaffney4, P. Garrett1, B. Greaves1, R. Gernhäuser3, C. Henrich2, S. Ilieva2, A. Mentana5, J. Refsgaard5, M. Seidlitz6, C. Svensson1, N. Warr6 1 Department of Physics, University of Guelph, Guelph, Canada 2 Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany 3 Physik Department E12, Technische Universität München, Garching, Germany 4 School of Eng. & Computing, University of the West of Scotland, Paisley, UK 5 Instituut voor Kern- en StralingsFysica, K.U. Leuven, Heverlee, Belgium 6Institut für Kernphysik, Universität zu Köln, Köln, Germany In the so called “Island of Inversion” around 32Mg, the ground states of nuclei exhibit a larger binding energy than expected from simple models. Extra binding energy can stem from an onset of defor- mation. Indeed, the systematics of excitation energies and B(E2) values in the Mg isotopes suggest a softening of the N=20 shell closure and it was suggested [1,2] that the nuclear tensor forcehasa major influence. On the other hand, shell evolution in the IOI can be understood as an effectofthe weakly-bound orbits with small angular momentum [3]. New insight comes from a recent publication [4], where a shell model interaction for the entire sdfp shell model space was deduced using the EKK-theory from realistic nucleon-nucleon interactions without a fit of two-body matrix elements. The new prediction is a drastic change to theearlier belief: the calculations suggest that only 25% of the ground state in 30Mg is made from 0p0h contri- butions, whereas 50% and 25% are due to 2p2h and 4p4h configurations, respectively. This contrasts with all previous investigations, which all conclude that 2p2h and 4p4h contributions in the ground state of 30Mg are as small as 5%. We present new data from experiment IS651 at the new HIE-ISOLDE facility, CERN. An intense radioactive beam of 28Mg (1.5x106pps) was scattered off a radioactive tritium target to populate states in 30Mg after two-neutron transfer. For the first time, the full HIE-ISOLDE beam energyof 9.5 MeV/u was used for a transfer experiment at MINIBALL. The significantly higher beam energy allows a more straightforward interpretation of spectroscopic factors compared to previous transfer experiments performed at ISOLDE (e.g. [5]). Gamma rays were detected with the high-granularity MINIBALL array, and recoiling protons were detected using the T-REX array of silicon detectors, now allowing full particle identification at backward angles. As the two-neutron transfer into the intruder 2p3/2 orbital is highly favoured, our experiment al- lows to extract the amount of intruder configurations in the ground state and excited states in 30Mg, experimentally. We present an unusually strong population of the first excited 0+ state in 30Mg, compared to the ground state population and discuss the implications for the EKK-theory and for our understanding of nuclear shell evolution in this region of the nuclear chart. [1] T.Otsuka et al., Phys. Rev. Lett. 95, 232502 (2005) [2] T. Otsuka et al., Phys. Rev. Lett. 104, 012501 (2010) [3] I. Hamamoto, Phys. Rev. C 85, 064329 (2012) [4] N. Tsunoda et al., Phys. Rev. C 95, 021304(R) (2017) [5] K. Wimmer et al., Phys. Rev. Lett. 105, 252501 (2010)
T3-2 Novel Magnetic Fusion Configurations (DPP) | Nouvelles configurations de fusion mag- nétique (DPP) / 2715
General Fusion’s Approach to Magnetized Target Fusion
Author: Michel Laberge1
1 General Fusion
Corresponding Author: [email protected]
While many physicists agree that fusion energy has the potential to be an exceptional solution to the world’s energy challenges, few can agree on how and when it will be done. Historically, two main
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approaches to develop fusion energy have been pursued by academic research: magnetic confine- ment and inertial confinement. Over the years significant progress has been made, but fusion power plants based on these two methods are still a ways away. Magnetic confinement operates with a plasma density of 1020 ions/m3 for time in seconds. Inertial confinement plasmas have a density of 1032 ions/m3 for a duration of 10’s of ps. Encouraged by advancing plasma physics and supporting technologies, interest in new approaches between these two extremes has emerged. Called Magne- tized Target Fusion (MTF) or Magneto-Inertial Fusion (MIF), these new approaches are in between the traditional ones, using compression (like inertial confinement) of a magnetized plasma (like mag- netic confinement) to achieve fusion conditions. Some argue that MTF could lead to practical fusion energy faster and for less money than the more traditional approaches. In recent years, the potential timeline and lower cost of fusion energy has resulted in many new companies entering the field with various approaches to fusion. After an overview of the fusion energy field, General Fusion’s MTF approach will be discussed.
R2-5 Detectors for Discovery (PPD/DAPI) | Détecteurs pour la découverte (PPD/DPAI) / 2716
The HALO-1kT Supernova Neutrino Detector
Author: Clarence Virtue1
1 SNOLAB
Corresponding Author: [email protected]
HALO-1kT is a proposed lead-based supernova neutrino detector for construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It is an evolution of the successful, but smaller, HALO detector at SNOLAB. HALO-1kT is expected to outperform HALO by a factor of 25 in sensitivity. The scientific collaboration is Canadian-led with major participation by Italian and American groups. HALO-1kT is timely and possible due to the experience gained in the construction and operation of HALO at SNOLAB; the availability of 1000 tonnes of lead from the OPERA experiment and the enthusiasm at LNGS to re-invigorate their supernova detection capabilities; and the end of the Amer- ican moratorium on the distribution of He-3 and its availability once again through the DOE Isotope Program. Neither HALO nor HALO-1kT can claim to be fully understood and calibrated until the neutrino-lead cross sections are known at supernova-relevant energies. A measurement of these cross sections at Oak Ridge National Laboratory’s Spallation Neutron Source is part of the Collabo- ration’s scientific objectives. An update on the project’s status will be presented.
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2717
15 - General Fusion Overview
Author: Delage Michael1
1 General Fusion
Corresponding Author: [email protected]
General Fusion is a private company developing Magnetized Target Fusion (MTF). Using the General Fusion MTF method, we first form a spherical tokamak inside a cavity in liquid metal. Compressed gas pushes on pistons that rapidly inject more liquid metal in the chamber, collapsing the cavity and compressing the trapped plasma to higher density and temperature. After a brief description of our system, we will look at General Fusion’s latest results forming a spherical tokamak by coaxial helicity injection. We have achieved plasma with sufficient density, temperature and lifetime to be good candidates for compression. The results from compressing some of these plasmas to higher density and temperature will be presented. Finally, we will look at our future plans and extrapolation to a point design for an MTF power plant.
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DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2718
16 - Fast Neutron Diagnostics on MTF Compression Experiments
Author: Myles Hildebrand1
1 General Fusion
Corresponding Author: [email protected]
Measurement of deuterium-deuterium (DD) fusion neutrons is a key diagnostic for magnetized target fusion (MTF) experiments being conducted at General Fusion (GF). When combined with other avail- able diagnostics, the detection of DD fusion neutrons can provide strong constraints on a model of plasma evolution during compression, in particular, ion temperature and density. GF plasma exper- iments have been monitored for high-energy particle emission using hydrocarbon liquid scintillator systems of a variety of designs. Scintillator output is digitized at high resolution over the course of the shot, which is followed by offline digital analysis of pulse height and shape of particle detection events. Pulse shape discrimination methods with sufficient accuracy and energy resolution enable separation of neutron detection events from high-energy photon detection events. GF is conducting a series of compression experiments, referred to as Plasma Compression Small (PCS), of which 16 have been completed. Results from the two most recent, PCS15 and PCS16 are presented here (see accompanying GF overview poster).
M2-11 Materials synthesis and characterization II (DCMMP) | Synthèse et caractérisation de matériaux II (DPMCM) / 2719
The nucleation of ZnO nanowires on sputter deposited metal sub- strates
Authors: Christopher Coutts1; Erol Girt1; Simon Watkins1
1 Simon Fraser University
Corresponding Author: [email protected]
ZnO is a II-VI semiconductor with a wide bandgap of 3.37 eV. This makes it a good candidate for transparent solar cells and for near-ultraviolet LEDs. In the following, a Ta/Ru/Au thin film is sputter deposited on a (110) Si substrate as a seed layer. The Ta layer appears to be amorphous while the orientation of the deposited metal films is found to be Ru (001), Au (111) by X-ray diffraction. This allows for epitaxial c-axis ZnO nanowire (NW) growth by metalorganic chemical vapour deposition at temperatures from 400˚ - 600˚ C. Such growth may be independent of substrate choice, as the orientation of the metallic seed layers will depend only on the characteristics of the amorphous Ta layer. Transmission electron microscopy (TEM) and XRD are used to demonstrate c-axis growth of ZnO on the deposited metal film. Scanning electron microscopy shows densely packed NWs. The height and separation increase with growth temperature while the misalignment increases with growth temperature. This is corroborated by rocking curve measurements which show increasing FWHM with growth temperature. Additionally, possible growth by vapour-liquid-solid (VLS) method is explored. Atomic force mi- croscopy (AFM) shows the successful formation of liquid Au droplets on the substrate surface fol- lowing exposure to Triethyl Gallium (TEGa) at temperature above the Au-Ga eutectic point. By adjusting length or flow rate of exposure the size, number, and height of nanoparticles can becon- trolled. Atomic force microscopy (AFM) shows that longer exposure (or higher flow) leads to fewer, larger particles of greater height on the substrate surface. Under VLS growth, this would allow tuneability of NW dimension and dispersion on the substrate surface. However, TEM and energy dispersive spectroscopy (EDS) indicate that higher temperature growths may be necessary to achieve NW growth by VLS.
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R2-3 Quantum Optics and Ion traps (DAMOPC) | Optique quantique et pièges d’ions (DPAMPC) / 2720
Surface-Plasmon Polaritons at Lossy Curved Interfaces
Authors: Nafiseh Sang-Nourpour1; Barry Sanders2
1 Department of Mechanical Engineering, University of Alberta 2 Institute for Quantum Science and Technology, University of Calgary
Corresponding Authors: [email protected], [email protected]
We construct a model for surface-plasmon polaritons propagation along lossy curved interfaces and introduce a set of conditions to characterize surface-plasmon polaritons propagation at these inter- faces. Mathematically, we employ conformal transformation to map the curved interfaces between lossy linear, isotropic and homogeneous materials to planar interfaces between lossy inhomoge- neous materials. Proceeding from Maxwell’s equations, we then derive the dispersion equations of surface-plasmon polaritons at homogeneous curved and inhomogeneous planar interfaces. We solve the dispersion equation at the inhomogeneous materials planar interfaces as a consistency check and to give intuition about the homogeneous materials at curved interfaces. We present ex- amples of metamaterials with both positive and negative electromagnetic susceptibilities forming a circularly curved interface with air. Our characterization of surface-plasmon polaritons is useful for checking the viability of the proposed application.
R2-7 Nuclear Structure IV (DNP) | Structure nucléaire IV (DPN) / 2721
Detailed Spectroscopy of Doubly-magic 132Sn with GRIFFIN
Author: K. Whitmore1 Co-authors: C. Andreiou 1; G.C. Ball 2; N. Bernier 3; H. Bidaman 4; V. Bildstein 4; M. Bowry 2; D.S. Cross 1; M.R. Dunlop 4; R. Dunlop 4; F.H. Garcia 1; A.B. Garnsworthy 2; P.E. Garrett 4; J. Henderson 2; J. Measures 5; B. Olaizola 2; J. Park 6; C.M. Petrache 7; J.L. Pore 1; J.K. Smith 8; D. Southall 9; M. Ticu 1; J. Turko 4; T. Zidar 4
1 Department of Chemistry, Simon Fraser University, Burnaby, BC 2 TRIUMF, Vancouver, BC 3 TRIUMF, Vancouver, BC; epartment of Physics and Astronomy, University of British Columbia, Vancouver, BC 4 Department of Physics, University of Guelph, Guelph, ON 5 University of Surrey, Guildford, United Kingdom 6 TRIUMF, Vancouver, BC; Department of Physics and Astronomy, University of British Columbia, Vancouver, BC 7 Centre de Sciences Nucl\’{e}aire et Sciences de la Mati\‘{e}re, CNRS/IN2P3, Universit\’{e} Paris-Saclay, Orsay, France 8 Department of Physics, Reed College, Portland, OR 9 University of Waterloo, Waterloo, ON
The region of neutron-rich tin isotopes near mass number 130 is of great interest to nuclear struc- ture. In particular, 132Sn with 50 protons and 82 neutrons is a doubly magic nucleus which provides an essential benchmark for the shell model far from stability. Understanding the structure of this nucleus provides a foundation to understand the single-particle nature of excited states in neigh- bouring isotopes. With no excited states below 4 MeV, 132Sn can be considered to be the most magic among heavy nuclei. In addition to nuclear structure considerations, isotopes in this region are also relevant to astrophysics, as their decay properties are essential to understanding r-process nucle- osynthesis and its role in creating the A = 130 abundance peak. The nucleus 132Sn has been studied following the β− decay of 132In at the ISAC facility at TRIUMF. A beam of 132In was delivered to the GRIFFIN decay station, where 16 HPGe detectors were used to detect gamma rays in addition to 20 plastic scintillators of SCEPTAR for beta-tagging. This powerful combination of tools has allowed for the identification of several weak γ-ray transitions as well as assignment of excited state spins via angular correlations. The experiment was also sensitive to the β-delayed neutron decay of 132In
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by observing γ rays from 131Sn and 131Sb; this experiment represents the first time in that decay has been measured with γ-rays. Results on the decay of 132In and γ spectroscopy of 132Sn will be discussed.
T4-10 Thinking Outside the Box (DPE) | Penser hors de la boîte (DEP) / 2722
Should Gauss’s Law Be Taught in First Year?
Author: Robert Hawkes1
1 Professor Emeritus, Mount Allison University
Corresponding Author: [email protected]
Gauss’s Law is one of the most elegant and powerful relationships in physics, but should it be taught in first year? On the one hand, it provides the framework to truly understand electric fields,isan entry point to Maxwell’s equations, and enables a beautiful introduction to important ideas of flux and symmetry. On the other hand, in first year students will not have the vector calculus background for Gauss’s law. Is it possible we do more more harm than good by introducing Gauss’s law too soon in the undergraduate curriculum? The session will feature a debate between physicists Robert Hawkes and Bob Hawkes on the question. The audience will be encouraged to add their voices on either side of the debate. At the conclusion the audience will be asked to vote.
T3-7 Frontiers in optics (DAMOPC) | Frontières en optique (DPAMPC) / 2723
New Strategies for Single Crystal Plasmonic Nanostructures and Plasmon-based Solar Energy Harvesting
Author: Gary W. Leach1
1 Simon Fraser University
Corresponding Author: [email protected]
Plasmon-based solar energy conversion relies on absorption and charge separation at rectifying, metal/dielectric interfaces. Hot electrons produced through plasmon decay can undergo internal photoemission (IPE) and injection into an adjacent dielectric material, generating useful photo- current and -voltage determined by the metal/dielectric material pair. Here, we describe our work to optimize plasmonic photovoltaic devices on smooth and nanostructured Ag/ZnO interfaces and identify the requirements for high quantum efficiency structures. We have (i) modelled the cap- ture of solar radiation by plasmonic metal/dielectric structures using finite difference time domain (FDTD) simulation methods, (ii) fabricated test devices, (iii) evaluated their optical, rectifying, and photovoltaic response, and (iv) characterized their materials properties using electron microscopy, spectroscopy and x-ray diffraction methods. We describe the challenges and opportunities ofthis and related technologies and introduce a new bottom-up approach to deposit single crystal epitaxial metal films and nanostructures from solution. While this chemistry allows for the subtractive manu- facture of nanostructure through ion beam milling, it also enables additive crystalline nanostructure using lithographic methods such as electron beam lithography to enable novel, large area, metama- terial arrays and high aspect ratio crystalline nanostructure. We anticipate that this new approach will have significant impact on this and other new plasmon-based nanotechnologies.
M2-2 Fundamental Symmetries (DNP) | Symétries fondamentales (DPN) / 2724
Page 170 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Measurement of the Stark Shift of the 7s-8s Transition in Fran- cium
Author: Tim Hucko1
1 University of Manitoba
Corresponding Author: [email protected]
Francium is an ideal candidate for atomic parity nonconservation (APNC) measurements, since APNC effects scale roughly with a Z3 dependence. Knowledge of francium’s atomic structure is key to interpreting APNC measurements, and can be studied through properties such as the Stark shift of the 7s → 8s transition. In our experiment we use magneto-optical traps to suspend francium atoms in vacuum between indium tin oxide coated field plates to measure the Stark shift. In this talk I will discuss our latest measurement for the single photon Stark shift of the 7s → 8s transition in francium 211. We gratefully acknowledge UMGF and GETS support by the University of Manitoba.
W1-11 Neutrinoless Double Beta Decay (DNP/PPD) | Double désintégration bêta sans neutrino (DPN/PPD) / 2725
Latest results from EXO-200 and status of nEXO
Author: Jacques Farine1
1 Laurentian University
Corresponding Author: [email protected]
The EXO-200 and nEXO Collaborations are searching for the neutrinoless double beta (0vbb) decay of 136-Xe using time projection chambers (TPCs) filled with enriched liquid xenon. EXO-200 has completed phase II operations in December 2018 with upgraded hardware. Highlights of EXO-200 contributions and final results will be presented. nEXO is a tonne-scale 0vbb decay search based on the ultra-low background liquid xenon technol- ogy validated by EXO-200. With about 5000 kg of xenon enriched to 90% in the isotope 136, nEXO has a projected half-life sensitivity of approximately 10E28 years. This represents an improvement in sensitivity of about two orders of magnitude with respect to current results. Based on the expe- rience gained from EXO-200 and the effectiveness of xenon purification techniques, we expect the background to be dominated by external sources of radiation. The sensitivity increase is, therefore, entirely derived from the increase of active mass in a monolithic and homogeneous detector, along with some technical advances perfected in the course of a dedicated R&D program. Hence the risk which is inherent to the construction of a large, ultra-low background detector is reduced, as the in- trinsic radioactive contamination requirements are generally not beyond those demonstrated with the present generation 0vbb decay experiments. Indeed, most of the required materials have been already assayed or reasonable estimates of their properties are at hand. The base design of the de- tector configuration will be presented. This design for nEXO presents a compelling path towardsa next generation search for 0vbb decay, with a substantial possibility to discover physics beyond the Standard Model.
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2726
19 -Pulsed-Target Magnetron-Enhanced ICP Plasma System
Authors: Alex Chang1; Ayub Khodaee1; Joel Moreno1; Lenaic Couedel1; Michael Bradley1
Page 171 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 University of Saskatchewan Plasma Physics Lab
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
In this poster we present a new pulsed-target magnetron-enhanced plasma system, with applications in plasma materials processing and fundamental plasma physics. This system embeds a high-density magnetron discharge within a relatively uniform medium-density Inductively Coupled Plasma (ICP). We report on experimental studies of this unique plasma system using an RF-compensated Langmuir probe for plasma density and electron temperature measurements, as well as a high-speed camera to capture rapidly moving plasma structures. Preliminary modelling results using the VSim PIC simulation code will also be presented.
T3-8 Radiation Therapy (DPMB) | Radiothérapie (DPMB) / 2727
Modern Applications of Monte Carlo Simulations in External Beam Radiation Therapy
Author: Tony Popescu1
1 BC Cancer Agency
Corresponding Author: [email protected]
Monte Carlo simulations of radiation transport have played an important role in medical applications over the past three decades. More recently, Monte Carlo methods have been used for such modern radiotherapy applications as 4D patient doses calculations that take into account anatomy variations during treatment, in-vivo patient-specific verification of the treatment delivery, or image-guided radiation therapy and the associated dose delivered to patients. Moreover, treatment machines with dynamic beam delivery and tumour tracking capabilities have been characterized by Monte Carlo generated phase space data. Several ultra-fast, GPU-based, Monte Carlo codes have been introduced in the past few years, opening the exciting prospect of using them for real-time adaptive radiation therapy. We will give an overview of these recent developments.
R2-5 Detectors for Discovery (PPD/DAPI) | Détecteurs pour la découverte (PPD/DPAI) / 2728
Commissioning the Radial Time Projection Chamber for the ALPHA- g antimatter gravity experiment
Author: Lars Dieter Martin1
1 TRIUMF
Corresponding Author: [email protected]
Antimatter is believed to be affected by gravity in exactly the same way as ordinary matterfora variety of good reasons, however this has never been measured directly. This will be tested by the ALPHA-g project, which uses a new vertical antihydrogen trap based on the previous ALPHA de- sign (Antihydrogen Laser Physics Apparatus, the first experiment to trap antihydrogen in 2010). As in previous ALPHA experiments, the trapped antihydrogen is detected via its charged annihilation products after switching off the trap. In order to be sensitive to small gravitational effects, thesetup extends more than 2 metres in the vertical direction, requiring the particle detection system to cover a large volume with good tracking accuracy. The design chosen to replace the previous experiments’ silicon strip detectors is a radial time-projection-chamber (rTPC) filled with an Argon/CO2 gas mix- ture. The circumstances of the experiment necessitate the recording of a large number of signals thatneed to be digitized and extracted with very little space for electronics and cabling. Dedicated electronics
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were developed at TRIUMF to address this problem. The specific parameters of the chamber together with the requirement to observe minimum-ionizing particles leads to relatively complex signals on the detector electrodes, which have to be deconvolved in an iterative process. Following successful tests with a smaller prototype, the full-scale chamber was completed in early 2018 and the basic functionality of the detector was established at TRIUMF. Soon after, initial tests with cosmic rays lead to the observation of charged particle tracks. In July 2018 the detector was moved to CERN and commissioned with cosmic rays, after which it was combined with a plastic scintillator barrel and the rest of the experimental setup, consisting of a large 1T superconducting solenoid magnet and the inner cryostat containing the antihydrogen trap. The whole system was tested in its final vertical position with antiprotons annihilating in the trap and the rTPC tracking the resulting pions.
T4-2 Plasmas in Different Regimes: Hot and Cold (DPP) | Plasmas en régimes différents: chauds et froids (DPP) / 2729
The effect of hyper-resistivity on nonlinear resistive tearing modes
Authors: Ding Li1; W Yang1; X.Q. Xu2
1 Institute of Physics, Chinese Academy of Sciences 2 Lawrence Livermore National Laboratory
Corresponding Author: [email protected]
The effects of hyper-resistivity on nonlinear tearing modes [1], on the nonlinear peeling-ballooning modes [2], and on magnetic reconnection in astrophysical plasma [3] was investigated. In this pre- sentation, the nonlinear tearing modes with resistivity and hyper-resistivity H has been analytically investigated. In contrast to the flux average method used by previous works, the quasilinear method [4] has been extended to obtain the time evolution equation for nonlinear tearing modes. Starting from the reduced MHD equations, the mode equation for nonlinear tearing mode includ- ing resistivity and hyper-resistivity can be derived by using the perturbation theory and boundary layer theory. The nonlinear evolution equation can be obtained by using the Fourier transforms and the asymptotic matching condition. This equation could describe the time evolution of nonlinear tearing modes with resistivity and hyper-resistivity. However, it is very difficult to get its analytical solution directly. At moment, two solutions for limiting cases and one solution for general case are presented here. For the case where resistivity dominates in the inner region, one obtains , while for the case which is dominated by hyper-resistivity, one has [5]. For the general case where hyper-resistivity and re- sistivity are in the same order, recently we obtain a time evolution of perturbed magnetic flux as . It is found that the destabilized effect of hyper-resistivity is lesser than that of resistivity onthe growth of nonlinear tearing mode. [1] P. K. Kaw, E. J. Valeo and P. H. Rutherford, Phys. Rev. Lett. 43 (19), 1398-1401 (1979). [2] X. Q. Xu, B. Dudson, P. B. Snyder, M. V. Umansky and H. Wilson, Phys. Rev. Lett. 105 (17), 175005 (2010). [3] G. Vekstein, Phys. Plasmas 23 (2), 024502 (2016). [4] D. Li, Physics of Plasmas 2 (9), 3275-3281 (1995). [5] W. Yang, D. Li, and X. Q. Xu, Chin. Phys. Lett. 35(6), 065201(2018).
R2-8 Ultracold Neutrons (DNP/PPD) | Neutrons ultrafroids (DPN/PPD) / 2730
Producing ultracold neutrons with a spallation source and super- fluid helium
Author: Wolfgang Schreyer1
Page 173 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 TRIUMF
Corresponding Author: [email protected]
Ultracold neutrons are an ideal tool to do precise measurements of fundamental properties of the neutron. However, such measurements are currently limited by the small number of ultracold neu- trons that the handful of operational sources worldwide can provide. The TRIUMF UltraCold Advanced Neutron (TUCAN) collaboration has recently produced thefirst ultracold neutrons at TRIUMF, using a new, dedicated spallation neutron source and superfluid he- lium to convert them to ultracold energies. Based on the same principles and the experience gained with this prototype, we are currently designing a new ultracold-neutron source that will go into operation in 2021 and provide the highest UCN density in the world. This presentation will show results of the first UCN-production runs at TRIUMF, compare themto simulations, and show how we use these simulations to optimize the new source.
M2-2 Fundamental Symmetries (DNP) | Symétries fondamentales (DPN) / 2731
Using PENTrack to study systematics in the neutron electric dipole moment measurement at TRIUMF
Author: Sean Vanbergen1
1 TRIUMF
Corresponding Author: [email protected]
The TRIUMF UltraCold Advanced Neutron (TUCAN) collaboration is currently engaged in building a next generation ultracold neutron (UCN) source, with a neutron electric dipole moment (nEDM) measurement as its flagship experiment. A permanent EDM is a violation of CP-symmetry, and thus the nEDM is relevant in standard model extensions and the baryon asymmetry problem. The nEDM measurement is currently in the design phase, for which detailed studies of systematic effects in the experiment are crucial. To study these effects the TUCAN collaboration is using PENTrack, a particle and spin tracking software package developed for simulating UCNs. Many of the systematic effects in the nEDM experiment arise due to inhomogeneities in the electromagnetic fields, which affect the neutron spin precession. PENTrack’s functionality allows these effects to be studiedwith realistic geometries and fields. This talk will discuss the use of PENTrack in performing such studies and how these results relate to the nEDM experiment.
T2-9 Fields and Strings I (DTP) | Champs et cordes I (DPT) / 2732
Boundary conditions, zero modes, and spacetime entropy
Author: James Sully1
1 University of British Columbia
Corresponding Author: [email protected]
How do we describe the local Hilbert space of a continuum field theory? And does this have lessons to each us about the emergence of spacetime in AdS/CFT? I will describe how to define the Hilbert space of an interval in a CFT without turning to abstruse mathematics. For CFTs with a gravitational dual, this leads to a theory of gravitational membranes and new insights for understanding spacetime entropy.
Page 174 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2733
Gamma Ray Spectroscopy of 34Ar Using Fusion Evaporation
Author: Isaiah Djianto1 Co-authors: C. Andreoiu 2; F.H. Garcia 3; J.L. Pore 3; A. Goasduff 4; D. Testov 4; G. Jaworsky 4; K. Hadynska 4; J. Mabiala 4; T. Marchi 4; D. Napoli 4; J.J. Valiente-Dobon 4; D. Menegazzo 4; D. Bazzacco 4; S.M. Lenzi 5; M. Siciliano 5; A. Boso 5; P.R. John 5; D. Mengoni 5; F. Recchia 5; B. Bastin 6; A. Gadea 7; R. Austin 8; B. Melon 9; M. Rochinni 9; A. Nannini 9; G. Benzoni 10; E. Sahin 11; J. Grebosz 12; C. Petrache 13
1 Simon Fraser University 2 Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada 3 Department of Chemistry, Simon Fraser University, Burnaby, BC 4 INFN Laboratori Nazionali di Legnaro 5 Dipartimento di Fisica e Astronomia, Universita di Padova and INFN Sezione di Padova 6 GANIL 7 Instituto de Fisical Corpuscular 8 St. Mary’s University 9 INFN Sezione di Firenze 10 INFN Sezione di Milano 11 Department of Physics, University of Oslo 12 Instytut Fizyk Jadrowej PAN 13 IPNO, CNRS, IN2P3 - Universite Paris-Sud
Corresponding Authors: [email protected], [email protected]
One of the most prominent theories in describing nuclei is the nuclear shell model, which has ac- curately predicted many experimental trends in the atomic mass region of A=20-60 and beyond. One way to examine this model is by studying mirror nuclei-which have exchanged numbers of protons and neutrons. Differences between mirror nuclei’s analogue nuclear levels and their de- cay patterns help in quantifying isospin symmetry in the nuclear force. Of particular interestis studying the neutron deficient 34Ar and compare its structure to its mirror nucleus 34S. Whilst 34S has been extensively studied, 34Ar has only been studied at low energies so far. In addition, shell model calculations of mirror energies for A=34 Ar-Cl-S seem to disagree with available experimental data. Excited states were populated in the 34Ar nucleus by a fusion evaporation reaction at the Laboratori Nazionali Legnaro (LNL-INFN) in 2015 using a 12C beam to bombard a stationary 24Mg target, and by evaporation of two neutrons from the 36Ar compound nucleus. Other stronger channels were opened in this reaction which produce a high background with respect to the 34Ar spectrum. Gamma rays were detected by the GALILEO array composed of 25 HPGe detectors. The EUCLIDES charged particle detector associates charged particles being evaporated, whilst the neutron wall array tagged neutrons. Coincident events between the charged particles, neutrons, and gamma rays are used to create spectra of specific nuclei. Analysis of this experiment will serve to provide more experimental data for the shell model to better extend our understanding of nuclei in this mass region.
T4-7 Optical Spectroscopy and control (DAMOPC) | Spectroscopie optique et contrôle (DPAMPC) / 2734
Harnessing amplified ultrafast laser pulses for studying and con- trolling quantum materials
Author: David Jones1
1 UBC
Page 175 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
Quantum materials exhibit a range of astonishing phenomena that embody the central scientific questions currently challenging condensed matter physics. Within these systems, ultrashort light pulses can create controlled non-equilibrium electronic conditions to reveal physical properties not accessible at equilibrium. Beyond uncovering the interaction mechanisms between electrons, lattice, and spin, it is also a new and rich landscape in which photonic-based coherent control methods can be implemented with goals of driving and controlling internal quantum states in the condensed phase. I will discuss our efforts toward developing technology and techniques for probing quantum materials along with results from these studies.
M1-8 Neutrinoless Double Beta Decay and Strangeness (DNP) | Double désintégration bêta sans neutrino et étrangeté (DPN) / 2735
A linear quadrupole ion trap for barium tagging in nEXO
Author: Yang Lan1 Co-authors: Thomas Brunner 2; Jens Dilling 3; Jacques Farine 4; Razvan Gornea 5; Giorgio Gratta 6; Anna Kwiatkowski 1; Thomas Koffas 7; Kevin Murray 2; John Orrell 8; Moritz Pascal Reiter 9; Xiao Shang 2
1 TRIUMF 2 McGill University 3 triumf/UBC 4 Laurentian University 5 Carleton University 6 Stanford University 7 Carleton University (CA) 8 Pacific Northwest National Laboratory 9 TITAN
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Barium tagging is a future upgrade for nEXO (next-generation Enriched Xenon Observatory), a planned experiment that will search for neutrinoless double beta decay (0νββ) in ¹³⁶Xe. If detected, 0νββ would confirm that neutrinos are their own anti-particles and reveal their absolute masses. Due to the long half-life (>10²⁶ years) of 0νββ, a low background is critical to achieve the necessary detection sensitivity. Barium tagging is the ultimate method for rejecting 0νββ-like background events by confirming the production of ¹³⁶Ba as the daughter isotope of this decay. This can bedone by extracting ions from the xenon detector, then identify barium through laser spectroscopy in a Linear Quadrupole Ion Trap (LQIT). The ions will then be sent to a Multi-reflection TimeofFlight (MR-TOF) mass spectrometer, to distinguish ¹³⁶Ba from other naturally occurring barium isotopes as well as to identify other contaminants. The LQIT has been simulated and optimized to achieve high efficiencies in ion trapping and transmission. The development of the LQIT, from simulations to most recent experimental results of a prototype, will be presented.
W2-6 Local probes (DCMMP) | Sondes locales (DPMCM) / 2736
Muon as a unique probe in condensed matter physics
Author: Kenji Kojima1
1 Centre for Molecular and Materials Science
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Corresponding Author: [email protected]
Muon is an elementary particle with spin ½ , capable to measure the local magnetic field inside the matter either internal origin (magnetism) or externally applied (field exclusion due to the supercon- ductivity). This characterizes the muon particle, or the measurement scheme known as muon spin rotation/relaxation/resonance (µSR) as the most sensitive probe of magnetism and superconduc- tivity [1,2]. Another important aspect of µSR is the characteristic of the muon as a radio active isotope of a pro- ton: the implanted muon takes the same position and the charge state of a hypothetical Hydrogen in the matter, and the hyperfine coupling parameter to the electron spin systems may beevaluated through the time evolution of the muon spin. This provides a valuable information about an isolated Hydrogen in semiconductors [1,2] and Hydrogen radicals in chemical reactions [1,3]. The µSR is a unique probe in condensed matter physics, and is available in research proposal basis to Canadian and International users at TRIUMF in the UBC campus. In the presentation, the author will introduce recent research activities and invite new users to the facility. Reference [1] for recent research activities, please refer to proceedings of international conference of muon spin rotation/relaxation/resonance, muSR2017 (Sapporo), 2014 (Grindelwald), 2011 (Cancun) etc. [2] for example, M. Hiraishi et al., Nat. Phys. 10, 300 (2014). [3] for example, K. Shimomura et al. Phys. Rev. B 92, 075203 (2015). [4] for example, S. Ito et al. Angew. Chem. Int. Ed., 57, 8608 (2018).
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2737
57 - The 5s→6s Stark shift measured via two-photon spectroscopy in laser-trapped rubidium
Authors: Michael Kossin1; Mukut Kalita2; Timothy Hucko3; Luis Orozco4; Alexandre Gorelov1; Austin DeHart1; Gerald Gwinner5; Matthew Pearson1
1 TRIUMF 2 Triumf 3 University of Manitoba, TRIUMF 4 University of Maryland, College Park 5 University of Manitoba
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
We have measured the Stark shift of the 5s→6s transition in rubidium using two-photon spec- troscopy. The Rb atoms are held in a magneto-optical trap (MOT) at the center of two optically- transparent field plates providing unhindered optical access for the MOT beams. The Stark shiftwas determined for electric fields from 0.350 kV/cm to 5.249 kV/cm. The 993 nm spectroscopy laserwas referenced with a Pound-Drever-Hall frequency offset lock to a ULE cavity with a frequency stability better than 200 kHz/day. We will present the results of these measurements and comparethemto theory from literature.
W1-11 Neutrinoless Double Beta Decay (DNP/PPD) | Double désintégration bêta sans neutrino (DPN/PPD) / 2738
Characterization of Angular Dependency of Photon Detection Ef- ficiency of VUV Silicon Photo-Multipliers
Page 177 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Fatemeh Edalatfar1
1 Fatemeh
Corresponding Author: [email protected]
During the last decade, Silicon Photo-Multipliers (SiPMs) have emerged as a compelling photo- sensor solution. Low-voltage power, optimal operation at cryogenic temperature, and low radioac- tivity levels with negligible gain fluctuations are among the advantages of SiPMs over the widely used PhotoMultipliers Tubes (PMTs). Accordingly, large-scale low-background cryogenic experi- ments, such as the next-generation Enriched Xenon Observatory experiment (nEXO), are migrating to a SiPM-based light detection system. nEXO aims to probe the boundaries of the standard model of particle physics by searching for neutrino-less double beta decay (0νββ) of Xe. This lepton number violating process would imply that neutrinos are Majorana fermions. The photo sensors of these experiments should meet some specific requirements. The aim of this presentation is to evaluate the relative photon detection efficiency of Hamamatsu VUV4 Multi-Pixel Photon Counters (MPPC)s (S/N: S13370-6152) at different incident angles which is important for simulations of the overall per- formance of the system. The devices tested have a micro-cell pitch of 50μm and an effective photosensitive areaof6×6 mm2.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2739
8 - Thin Film Characterization
Authors: Fatemeh Edalatfar1; Wrick Dasgupta1
1 TRIUMF
Corresponding Authors: [email protected], [email protected]
Using a newly commissioned VUV transmissometer at TIUMF, the optical constants of the thin films, including MgF2, LiF2, etc from 120nm to 320nm are evaluated. The VUV transmissometer is a transmission and reflection evaluation system which is designed to deliver vacuum-ultraviolet (VUV) to ultraviolet (UV) radiation to a target sample and measure the reflectance, transmission or fluorescence of the target.
DPE Poster Session & Student Poster Competition Finals (5) | Session d’affiches DEP et finales du concours d’affiches étudiantes (5) / 2740
13 - How the UBC Young Women for Science inspires students to study STEM
Author: Teagan Phillips1
1 University of British Columbia
Corresponding Author: [email protected]
Two years ago, I founded the UBC Young Women for Science, a volunteer outreach club based in Vancouver, which brings female UBC STEM undergraduate students from various fields into high schools to speak about their subjects and research while including demonstrations and activities. Our goal is to reduce the gender gap in STEM by inspiring and encouraging more young girls to pur- sue STEM. There is a significant lack of female role models in STEM, especially in fields likephysics. The UBC Young Women for Science shows students that there are actually many great women study- ing all STEM fields, so that girls feel more confident in studying STEMtoo!
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As a physics student, I believe it’s especially important to encourage girls at the high school level to study physics, because there is already a significant lack of women studying physics at the under- graduate level (which is not present in many other STEM fields). So far, we have done 42 presentations at 14 schools in Vancouver, West Vancouver, North Vancou- ver, Burnaby, and New Westminster, speaking to over 1000 students! About half of the students we present to are girls. We have received an NSERC grant to do presentations in the Okanagan Valley at the end of April (2019), and currently have 12 presentations booked at 4 schools. This year, we also hosted the UBC Women and STEM Conference on March 2, 2019. Therewere 49 attendees, including high school, undergraduate, and graduate students, as well as alumni, fac- ulty, and working professionals from Sutherland Secondary, New Westminster Secondary, Langara College, SFU, BCIT, Capilano University, UBC, SCWIST, and the Government of Canada. Our three main speakers were Dr. Janis McKenna (Physics, UBC), Kristin Wilkes (CIO of Capilano University), and Dr. Lesley Shannon (Computer Engineering, SFU & NSERC). The conference was put together and run entirely by our undergraduate executive team andaimed to create a stronger dialogue about the gender gap in STEM throughout all levels of education and to encourage ways of addressing the disparity.
M1-9 Soft Condensed Matter I (DCMMP) | Matière condensée molle I(DPMCM) / 2741
Direct Measurement of the Dynamic Modulus of Gellan Gum Micro- Capsules
Authors: Yun-Han Huang1; Abhijeet Kamble1; Fluer SalmonNone; Mariano Michelon2; Bruna Leopercio3; Marcio Carvalho3; John Frostad1
1 University of British Columbia 2 PUC - Rio 3 PUC Rio
Corresponding Author: [email protected]
Micro-capsules are increasingly being studied as models for cells, as drug delivery vehicles, and even as devices for enhanced oil recovery form porous substrates. As such, understanding of their mechanical properties is critical for rational design and optimal performance. Here we describe experiments using a Cantilevered-Capillary Force Apparatus to probe the dynamic (or complex) modulus of micro-capsules under axial compression. The micro-capsules used in this study are ap- proximately 200 microns in diameter and are composed of a sunflower-oil core surrounded bya gellan-gum shell.
T3-7 Frontiers in optics (DAMOPC) | Frontières en optique (DPAMPC) / 2742
Optical microscopy with kinky photons
Authors: Daniel Higginbottom1; Gabriel Araneda2; Stefan Walser3; Colombe Yves2; Jürgen Volz3; Arno Rauschenbeutel3; Rainer Blatt2
1 Simon Fraser University 2 Institut für Experimentalphysik, Universität Innsbruck 3 Vienna Center for Quantum Science and Technology, TU Wien-Atominstitut
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Photons emitted from atomic transitions may be twisted; angular momentum opposite to theatom’s internal configuration change is distributed between the photon’s spin (polarization) and orbital an- gular momentum depending on the angle of observation. Photons twisted perpendicular to their
Page 179 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
angle of observation propagate through an aperture at an angle, and measuring the photon’s dis- placement at an image plane constitutes a weak angular momentum measurement. Remarkably, photons from an elliptical dipole are not only twisted, but kinky, with more than ±¯h of angular momentum per photon at the aperture, larger than the angular momentum of the dipole eigenstates or the corresponding atomic transitions. Such ‘supermomentum’ is a consequence of weak measurement amplification in a spin-orbit cou- pled optical field. Chiral light-matter interactions of this kind promise exciting new capabilities for photonic devices, and both consequences and opportunities for super-resolution microscopy. We measure optical spin-orbit coupling and supermomentum from two dipole photon sources. We image single photons emitted from a trapped atom at the focus of a high-aperture objective and demonstrate wavelength-scale, chirality-dependent shifts between photons from opposing dipole transitions. Our elliptical dipole light source is a sub-wavelength gold nanoparticle and we observe supermomentum in the small-aperture nanoparticle image. This supermomentum becomes arbitrar- ily large as the aperture vanishes. This optical spin-orbit effect can lead to systematic wavelength-scale errors in the localization of an elliptically polarized emitter. Such errors are present even for ideal, focussed, aberration-free imaging systems and reveal that the paraxial approximation is fundamentally inadequate for opti- cal super-resolution microscopy, even when the observation aperture is very small. This finding applies to the localization of objects using any wave carrying angular momentum orthogonal to the direction of observation, and is relevant for super-resolution microscopy techniques, which achieve resolutions two orders of magnitude smaller than the supermomentum shifts observed here.
M2-10 Soft condensed matter II (DCMMP) | Matière condensée molle II (DPMCM) / 2744
WITHDRAWN - 2-Dimensional Vibrational Sum Frequency Gen- eration Spectroscopy of Organic Monolayers
Authors: Anna Schiffer1; Gary Leach1; Michaael HemsworthNone
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
Vibrational sum frequency generation (SFG) spectroscopy is a non-destructive interface-specific non-linear optical spectroscopy that delivers information about the structure and composition of interface environments. Coupling and energy flow through vibrational modes at surfaces areim- portant and of interest in areas ranging from membrane biophysics and biochemistry, to materi- als science, electrochemistry, and heterogeneous catalysis. SFG spectroscopy leverages the non- centrosymmetric environment of the interface to mix two incident electric fields and provide a coher- ent scattered field at their sum frequency. For fields resonant with the vibrational modes ofinterface molecules, the sum frequency signal provides valuable information about local interface structure and energetics. 2-Dimensional SFG (2D-SFG) spectroscopy extends these studies to provide direct information about molecular interactions and dynamics. Here, we describe the construction of a novel collinear 2D-SFG spectrometer and its application to the vibrational spectroscopy of highly ordered organic monolayers at the CaF2/Air interface. A three pulse IR sequence generated from a dual output Ti:sapphire-based optical parametric amplifier (OPA) and birefringent wedge pair create a highly phase stable train of IR pulses with controllable time delays. This 100 fs IR pulse sequence is combined with a narrow bandwidth picosecond up-converting 800 nm pulse to yield a broadband SFG spectrum. Spectra captured as a function of IR pulse sequence delays are then processed to yield 2D-SFG spectra, providing information about the molecular interactions, vibrational couplings and vibrational dynamics of the organic monolayer. Here we report the vibrational couplings and dy- namics of the alkyl chain vibrational modes of supported ordered stearate chains in the CH spectral region to reveal their unusual dynamics and strong mode couplings.
T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2746
Page 180 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Beta Decay of 80,82-Ga with GRIFFIN and Shape Coexistence in 80,82-Ge
Author: Aimee Bell1 Co-authors: C. Andreoiu 1; F. A. Ali 2; Gordon Ball 3; Nikita Bernier 3; Soumendu Sekhar Bhattacharjee 3; M. Bowry 4; Robin Coleman 5; I. Dillmann 4; Isaiah Djianto 1; A.M. Forney 6; F.H. Garcia 7; A. B. Garnsworthy 4; Melanie Gascoine 1; Greg Hackman 3; Kyle Leach 8; A. N. Murphy 3; C. Natzke 8; B. Olaizola 4; Kevin Ortner ; E. E. Peters 9; Costel Petrache 10; M.M. Rajabali 11; Kurtis Raymond 1; C. E. Svensson 12; G. Tocabens 13; R. Umashankar 3; K. Whitmore 14; Jonathan Williams 1; Daniel Aaron Yates 15
1 Simon Fraser University 2 Department of Physics, University of Guelph, Guelph, Ontario 3 TRIUMF 4 Physical Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia 5 University of Guelph 6 University of Maryland College Park 7 Department of Chemistry, Simon Fraser University, Burnaby, BC 8 Colorado School of Mines 9 University Of Kentucky 10 University Paris Sud 11 Tennessee Technological University 12 Department of Physics, University of Guelph, Guelph, Ontario 13 Universite Paris-Sud 14 Department of Physics, Simon Fraser University, Burnaby, British Columbia 15 TRIUMF (CA)
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Shape coexistence in atomic nuclei, the existence of structures with different degrees of deforma- tion in a very narrow energy range, is an exciting phenomenon that is present across the nuclidic chart. A recent theoretical study[1] using large scale shell model calculations predicted a well de- formed prolate band at a low excitation energy in the doubly magic 78Ni nucleus which indicated the presence of shape coexistence very far from stability. At the same time, another experiment[2] + 80 observed an intruder 02 state in Ge and interpreted this as evidence of shape coexistence. In our β-decay experiment, we aim to perform comprehensive spectroscopy of the 80Ge and 82Ge nuclei + and investigate the evolution of their respective intruder excited 02 states. An experiment to search for shape coexistence in 80Ge and 82Ge has been performed at the ISAC- TRIUMF facility. The 80Ge and 82Ge isotopes were formed from the β-decay of their parent isotopes, 80Ga and 82Ga respectively. The 80Ga and 82Ga beams were produced by the ISOL technique using a 500 MeV proton beam with a 10 µA current colliding with a UCx target. A specialized ion source was used to suppress Rb contamination. The β-decay was measured using the GRIFFIN spectrom- eter which was equipped with 15 HPGe detectors for gamma ray detection, plastic scintillators for β-γ tagging, the PACES array which has 5 Si(Li) detectors for conversion electron spectroscopy and 8 LaBr3 scintillators for fast timing measurements of nuclear levels. Using this versatile array, cor- related γ-γ, γ-electron and electron-electron data have been acquired simultaneously, providing a highly detailed level scheme for 80Ge. The preliminary results of this data analysis will be presented. \newline [1] F. Nowacki, A. Poves, E. Caurier and B. Bounthong, PRL 117 272501 (2016). [2] A. Gottardo et al., PRL 116, 182501 (2016).
M-PLEN2 Plenary Session | Session plénière - N. Ji, Univ. of California at Berkeley / 2747
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Imaging the brain at high spatiotemporal resolution / Imagerie cérébrale à haute résolution spatiotemporelle
Author: Na Ji1
1 Berkeley
Physics has long employed optical methods to probe and manipulate matter on scales from the in- finitesimal to the immense. To understand the brain, we need to monitor physiological processes of single synapses as well as neural activity of a large number of networked neurons. Optical mi- croscopy has emerged as an ideal tool in this quest, as it is capable of imaging neurons distributed over millimeter dimensions with sub-micron spatial resolution. Using concepts developed in astron- omy and optics, my laboratory develops next-generation microscopy methods for imaging the brain at higher resolution, greater depth, and faster speed. By shaping the wavefront of the light, we have achieved synapse-level spatial resolution through the entire depth of the primary visual cortex, op- timized microendoscopes for imaging deeply buried nuclei, and developed high-speed volumetric imaging methods. I will discuss our recent advances as well as their applications to understanding neural circuits.
La physique a longtemps employé des méthodes optiques pour sonder et manipuler de la matière à toutes les échelles, et ce, de l’infinitésimal à l’immense. Pour comprendre le cerveau, nous de- vons surveiller les processus physiologiques de simples synapses ainsi que l’activité neurale de neu- rones en réseau. La microscopie optique s’est révélée comme un outil idéal dans cette quête car elle est en mesure de produire des images de neurones répartis sur des dimensions supérieures au mil- limètre, avec une résolution spatiale inférieure au micron. En utilisant des concepts développés en astronomie et en optique, mon laboratoire conçoit des méthodes de microscopie de nouvelle généra- tion pour l’imagerie cérébrale à des résolutions et des profondeurs plus élevées, et à des vitesses plus rapides. En façonnant le front d’onde de la lumière, nous avons atteint une résolution spatiale à l’échelle de la synapse pour toute la profondeur du cortex visuel primaire, nous avons optimisé des micro-endoscopes ou l’imagerie de noyaux profondément enfouis, de même que développé des méthodes d’imagerie volumétrique à haute vitesse. Je discuterai de nos avancées récentes, ainsi que de leurs applications pour la compréhension des circuits neuronaux.
R-PLEN2 - Plenary Session | Session plénière - A. Weaver, U. Victoria / B.C. Green Party | Parti verte de C.B. / 2748
Global warming: A question of priorities / Réchauffement clima- tique : une question de priorités
Author: Andrew Weaver1
1 Green Party / Parti vert, University of Victoria / Université de Victoria
Despite being well-understood scientifically, the challenge of global warming remains hotly debated at the political and social level. I’ll talk about the historical foundations of the science of global warm- ing and the range of projections of climate change over the next century. I’ll discuss the Canadian and International policy framework and the reason why I gave up my Tier 1 Canada Research Chair to run as an MLA for the BC Green Party.
Bien qu’il soit très bien compris scientifiquement, le défi du réchauffement climatique reste vivement débattu aux niveaux politique et social. Je parlerai des fondements historiques de lasciencedu réchauffement climatique et d’un éventail de projections du changement climatique au coursdu prochain siècle. Je discuterai du cadre politique canadien et international et de la raison pour laquelle j’ai abandonné ma chaire de recherche de niveau 1 pour me présenter comme député pour le Parti vert de la Colombie-Britannique.
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R2-2 Membrane Biophysics Joint Session Part II (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes II (DPMB/DPMCM/SBC) / 2749
Computer simulations of biological membrane models: lateral structure and lipid-protein interactions
Author: Peter Tieleman1
1 University of Calgary, Dept. of Biochemistry
Corresponding Author: [email protected]
Biological membranes have a complex composition with hundreds of different lipids and a high pro- tein concentration. The nature of the lateral structure of membranes is hotly debated as experiments reach increasingly higher spatial and temporal resolution and simulations increasingly larger time and length scales. Coarse-grained simulations with the Martini model have enabled a significant jump in time and length scale for detailed simulations, and currently can reach of the order of 100 microseconds on systems of ca. 100 x 100 nm size on relatively available computers. We are par- ticularly interested the interactions between lipids and membrane proteins. The local environment around membrane proteins is uniquely shaped by the protein surface, resulting in a local compo- sition and membrane properties that differ significantly from the average properties of the lipids that make up the membrane model. This may play an important role in shaping the lateral struc- ture of biological membranes. This type of simulation also enables detailed studies on more specific interactions.
R1-2 Membrane Biophysics Joint Session Part I (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes I (DPMB/DPMCM/SBC) / 2750
In-Vivo Solid-State NMR for the Study of Biological Membranes
Author: Dror Warshawski1 Co-authors: X. L. Warnet 2; M. Laadhari 1; A. Poulhazan 1; Z. Bouhlel 1; J-P. Bourgouin 1; M. Mahabadi 1; A. A. Arnold 1; I. Marcotte 1
1 Université du Québec à Montréal 2 CNRS-Université Paris Diderot, Institut de Biologie Physico-Chimique
Model membranes have been used for decades in solid-state NMR, and have been very useful to study lipid order and membrane proteins reconstituted in a bilayer environment. It is only since 2011 that solid-state NMR has been extended to the study of membrane molecules within intact cells, sometimes even living cells (1). After a brief historical introduction, we will focus on recent results obtained in our laboratory. We will start with various living bacteria fed with deuterated fatty acids, and show how it can help assess bacterial membrane rigidity with 2H solid-state NMR. After optimizing the labelling procedure, we will show how it can be used to probe membrane health and interactions with antimicrobial peptides (2). We will then switch to more complex eukaryotic systems such as the micro-alga Chlamydomonas reinhardtii and show how 2D 13C magic-angle spinning solid-state NMR can tackle the assignment and structure of biomolecules such as lipids, proteins, sugars from the cell wall, and starch, directly within the cell (3). (1) X. L. Warnet, A. A. Arnold, I. Marcotte and D. E. Warschawski Biophys. J. 109:2461–2466 (2015) (2) V. Booth, D. E. Warschawski, N. P. Santisteban, M. Laadhari and I. Marcotte Biochim. Biophys. Acta 1865:1500-1511 (2017) (3) A. Poulhazan, A. A. Arnold, D. E. Warschawski and I. Marcotte Int. J. Mol. Sci. 19:3817 (2018)
Page 183 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
R1-2 Membrane Biophysics Joint Session Part I (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes I (DPMB/DPMCM/SBC) / 2751
Changes in lipid membrane may trigger amyloid toxicity in Alzheimer’s disease.
Author: Zoya Leonenko1
Co-authors: E. Drolle 1; M. Robinson 1; S. Turnbull 1; N. Mei 1; C. Filice 1; B. Lee 1; E. Pavlov 1; E. Finot 1
1 University of Waterloo
Corresponding Author: [email protected]
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by dementia and memory loss for which no cure or prevention is available. Amyloid toxicity is a result of the non-specific interaction of toxic amyloid oligomers with the plasma membrane which induce damage and death of neuronal cells. Understanding these interactions is of high importance. We studied interaction of amyloid beta (1-42) peptide with lipid membrane using atomic force mi- croscopy (AFM), Kelvin probe force microscopy (KPFM), black lipid membrane (BLM) and surface Plasmon resonance (SPR). We demonstrated that composition, structure and properties of lipid mem- brane play an active role in amyloid binding and toxicity: changes in membrane composition mimick- ing AD increase amyloid binding and toxicity. Effect of lipid composition, the presence of cholesterol and melatonin are discussed. We demonstrated that membrane cholesterol creates nanoscale elec- trostatic domains which induce preferential binding of amyloid peptide, while membrane melatonin changes the properties of the membrane and protects the membrane from amyloid binding and dam- age. These findings contribute to better understanding of the molecular mechanisms of Alzheimer’s disease and aid to the developments of novel strategies for cure and prevention of AD. References:
1. E.Drolle, K.Hammond, A.Negoda, E.Pavlov, Z.Leonenko, Changes in lipid membranes may trig- ger amyloid toxicity in Alzheimer’s disease. PLOS ONE, 2017, 12(8), e0182194. 2. B Mehrazma, M Robinson, SKA Opare, A Petoyan, J Lou, FT Hane, A Rauk, Z Leonenko, Biochim- ica et Biophysica Acta (BBA)-Proteins and Proteomics 1865 (11), 1707-1718. 3. E.Drolle, R.M.Gaikwad, Z.Leonenko, Nanoscale electrostatic domains in cholesterol-laden lipid membranes create a target for amyloid binding. Biophysical Journal, 2012, 103(4), L27-L29. 4. E.Drolle, F.Hane, B.Lee, Z.Leonenko, Atomic force microscopy to study molecular mechanisms of amyloid fibril formation and toxicity in Alzheimer’s disease. J. of Drug Metabolism Reviews, 2014, 46(2): 207-223. 5. E.Drolle, N. Kučerka, M.I.Hoopes, Y.Choi, J. Katsaras, M. Karttunen, Z.Leonenko, Effect of mela- tonin and cholesterol on the structure of DOPC and DPPC membranes, Biochimica & Biophysica Acta: Biomembranes, 2013, 1828 (9): 2247-2254. 6. E. Drolle, A. Ollagnier, E. Finot, Z. Leonenko (2016). Surface Plasmon Resonance Imaging to Study the Molecular Mechanism of Alzheimer’s Disease. Allsensors. ISBN: 978-1-61208-523-4
R2-2 Membrane Biophysics Joint Session Part II (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes II (DPMB/DPMCM/SBC) / 2752
Molecular composition of the mitochondrial permeability transi- tion pore.
Author: Evgeny Pavlov1
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1 New York University, College of Dentistry
Corresponding Author: [email protected]
Mitochondrial damage caused by calcium overload is a critical step in stress-induced cell death dur- ing stroke and heart attack. This damage is caused by dramatic increase in permeability ofthemi- tochondrial inner membrane – a phenomenon known as Permeability Transition (PT). PT is caused by calcium induced opening of the large pore at the mitochondrial inner membrane. Molecular composition of the PT pore is not completely understood as is subject of hot debates. Here I will discuss current understanding of the mechanisms of PT pore formation and present our resent ex- perimental data of the electrophysiological recordings of PT pore activity in mitochondrial inner membrane from wild-type and mutant cells lacking putative components of the PT. Further, I will present recordings of the channel activity of the purified and fully synthetic components of the PTre- constituted into artificial planar lipid bilayers. Altogether our experiments suggest that PT canoccur by different mechanisms that involve such mitochondrial proteins as C-subunit of the ATP synthase and Adenine Nucleotide Translocator. Existence of several pathways for PT helps to resolve long standing controversies regarding its exact molecular composition.
M-PLEN1 - Plenary Session | Session plénière - D. Strickland, U.Waterloo / 2753
From Nonlinear Optics to High-Intensity Laser Physics / De l’optique non linéaire à la physique des lasers à haute intensité
Author: Donna Strickland1
1 University of Waterloo
The laser increased the intensity of light that can be generated by orders of magnitude andthus brought about nonlinear optical interactions with matter. Chirped pulse amplification, also known as CPA, changed the intensity level by a few more orders of magnitude and helped usher in a new type of laser-matter interaction that is referred to as high-intensity laser physics. In this talk, Iwill discuss the differences between nonlinear optics and high-intensity laser physics. The development of CPA and why short, intense laser pulses can cut transparent material will also be included. I will also discuss future applications.
Le laser a augmenté de plusieurs ordres de grandeur l’intensité de la lumière qu’on peut générer et il a donc donné des interactions optiques non linéaires avec la matière. L’amplification des impul- sions comprimées, ou AIC, a modifié le niveau d’intensité de quelques ordres de grandeur depluset contribué à l’avènement d’un nouveau type d’interactions laser-matière appelé physique des lasers à haute intensité. Mon entretien portera sur les différences entre l’optique non linéaire et la physique des lasers à haute intensité. Je parlerai aussi de l’essor de l’AIC et j’expliquerai pourquoi les impul- sions laser courtes et intenses coupent des matériaux transparents. J’aborderai également de futures applications.
R2-2 Membrane Biophysics Joint Session Part II (DPMB/DCMMP/BSC) | Session conjointe sur la biophysique des membranes II (DPMB/DPMCM/SBC) / 2754
Dying Escherichia coli cells absorb antimicrobial peptides, en- hancing the survivability of the cell culture
Author: Sattar Taheri-Araghi1
1 California State University
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Corresponding Author: [email protected]
Antimicrobial peptides (AMPs) are broad spectrum antibiotics that utilize electrostatics to selectively attack bacteria. In this talk, I present our discovery of a new class of antibiotic tolerance thatEs- cherichia coli exhibit against human AMPs LL37: the dying bacteria rapidly absorb a large amount of antibiotics helping the remaining cells survive. Like all antibiotics, AMPs need a minimum con- centration to inhibit growth of a bacterial culture. But in cultures with high cell density we observed two distinct subpopulations: a non-growing population that absorb peptides and a growing popula- tion that survive owing to the sequestration of the AMPs by dead cells. A mathematical model based on this binary picture reproduces various experimental observations, including the increase of the minimum inhibitory concentration with cell density (even in dilute cultures) and the extensive lag in growth introduced by sub-lethal dosages of AMPs.
T1-1 Soft Matter AM-1 (DCMMP) | Matière molle AM-1 (DPMCM) / 2755
Droplets as model systems for investigating 2D crystals, glasses, and the growth dynamics of granular aggregates
Author: Kari Dalnoki-Veress1
1 Department of Physics & Astronomy, McMaster University, and Gulliver Laboratory, ESPCI ParisTech, PSL Research University
Over the last years we have developed a method to produce monodisperse oil droplets in an aque- ous environment. By carefully tuning the adhesion forces between the droplets they provide model systems for studying various physical phenomena that are not accessible by investigating the molec- ular counterpart. Here I will present recent work on the transition from 2D crystalline aggregates, prepared from monodisperse droplets, to disordered glassy aggregates prepared from a bidisperse blend of large and small droplets. The aggregates are compressed between two parallel boundaries; crucially, one of the boundaries acts as a force sensor. The compression forces provide a signature of the aggregate composition and give insight into the energy landscape as the system transitions from the crystal to glass. In addition to the idealized 2D aggregates the same system of droplets can be used to investigate the formation of 3D clusters if the adhesion between droplets is sufficiently strong. The buoyant droplets accumulate underneath a glass slide which acts as the top ofaliquid cell, forming 3D aggregates. Droplets initially arrange to form crystals growing along the vertical direction. As a critical height is reached, the aggregate collapses and spreads horizontally on the glass slide, in an event analogous to avalanches in sand piles. We find that the geometry of such clusters is controlled by the balance between the adhesion strength and buoyancy.
T3-1 Soft Matter PM-1 (DCMMP) | Matière molle PM-1 (DPMCM) / 2756
Finding Myelin: Quantum mechanics in cow brains?
Author: Carl Michal1
1 Department of Physics & Astronomy, University of British Columbia
Myelin is the fatty insulating material that covers nerve axons in white matter brain tissue andspinal cord. A number of neurodegenerative diseases, the most prominent of which is multiple sclerosis, are associated with damage to myelin with consequent degradation of neuronal signal transmission and functional impairment. A number of magnetic resonance imaging techniques have been developed to characterize myelin in order to assess disease progression and the effectiveness of treatment and treatment candidates. Several of these imaging techniques will be discussed,with a focus on a new technique, misleadingly named inhomogeneous magnetization transfer (ihMT), which relies upon the quantum mechanics of the dipolar interactions between 1H nuclei in the hydrocarbon chains of myelin lipids. Working with in vitro bovine brain tissue and a variety of phantom samples, we
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have demonstrated that the original explanation for the technique, offered by its inventors, that the observed effect is associated with “hole burning” in inhomogeneously broadened NMR spectra, is not correct. We have shown that instead, ihMT is due to connections to the dipolar-coupled nuclear spin bath in the myelin lipid molecules. The equivalence between two coupled spin-1/2 particles and a single spin-1 allows a simple explanation of how the dipolar couplings in lipids give rise to the observed contrast in ihMT MRI images.
R-PLEN1 Plenary Session | Session Plénière - C. Dvorkin, Harvard / 2757
New Frontiers in Cosmology / Nouvelles frontières en cosmolo- gie
Author: Cora Dvorkin1
1 Harvard
Measurements of the Cosmic Microwave Background and the large-scale structure of the universe have made it possible to determine with great precision the universe’s inventory, as well as properties of its initial conditions. However, there are profound questions that remain unanswered.
Cosmological observations and galaxy dynamics seem to imply that 84% of all matter in the universe is composed of dark matter, which is not accounted for by the Standard Model of particles. The particle nature of dark matter is one of the most intriguing puzzles of ourtime.
The wealth of knowledge which is and will soon be available from cosmological surveys willreveal new information about our universe. I will discuss how we can use new and complementary data sets to improve our understanding of the particle nature of dark matter both at large and small scales.
Les mesures du fond diffus cosmologique et la structure à grande échelle de l’Univers ont permisde déterminer avec grande précision l’inventaire de l’Univers, ainsi que les propriétés de ses conditions initiales. Il y a cependant de sérieuses questions qui demeurent sans réponse.
Les observations cosmologiques et la dynamique des galaxies semblent donner à penser que 84 % de toute la matière composant l’Univers est de la matière noire, ce dont ne tient pas compte le modèle standard des particules. La nature particulaire de la matière noire est l’une des énigmes les plus intrigantes de notre époque. La masse de connaissances que les enquêtes cosmologiques dévoilent déjà et dévoileront fournira de nouvelles données sur notre Univers. J’exposerai le mode d’emploi des ensembles nouveaux et complémentaires de données afin nous permettre de mieux comprendre la nature particulaire dela matière noire, tant à petite qu’à grande échelle.
M1-11 Probing and controlling matter with light I (DCMMP) | Sonder et contrôler la matière avec de la lumière I (DPMCM) / 2758
Atomic-scale dynamics of collective charge and spin excitations
Author: Sebastian Loth1
1 Institute for Functional Matter and Quantum Technologies, University of Stuttgart and Max Planck Institute forSolid State Research, Stuttgart
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Corresponding Author: [email protected]
Spin and charge correlations are particularly pronounced in low-dimensional materials and enable new technologies that harness quantum behavior. Accessing these correlations on their intrinsic length and time scales is an important step towards a microscopic understanding of correlated- electron physics. We combine scanning tunneling microscopy with pump probe schemes to achieve ultrafast spec- troscopy of spin and charge dynamics with atomic spatial resolution. Using electronic pulse genera- tion [1] and optical excitation with THz pulses [2] it is possible to achieve time resolution between milliseconds and femtoseconds thereby matching the instrument to the dynamics of the investi- gated system. At nanosecond time resolution, we can track the spin dynamics of magnetic atoms on surfaces and identify miniscule magnetic interactions between few-atom spin chains [3]. At fem- tosecond time resolution, we can detect electron dynamics and follow the evolution of collective modes in a correlated-electron state at individual atomic defects. These experiments access the microscopic dynamics of quantum materials and highlight pathways to design and control matter at the single atom level. [1] S. Loth, M. Etzkorn, C. P. Lutz, D. M. Eigler, A. J. Heinrich, Science 329, 1628 (2010). [2] T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. J. Burgess, G. de los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, F: A. Hegmann, Nature Photon. 7 620 (2013). [3] S. Yan, L. Malavolti, J. A. J. Burgess, S. Loth, Science Adv. 3 e1603137 (2017).
M2-9 Magnetism and heavy fermions II (DCMMP) | Magnétisme et fermions lourds II DPMCM) / 2759
Anti-chiral order and damped spin waves in the topological semi- metal Mn3Ge
Author: Jonathan GaudetNone
The recent discovery of Anomalous Hall Effect in Mn3X (X=Sn,Ge) suggests the existence ofWeyl nodes in the electronic band structure of these non-collinear antiferromagnets [1]. The resulting coupling of electronic transport and magnetism in Mn3X presents important technological oppor- tunities. The magnetic properties of Mn3X are crucial to Weyl physics and to its implementation in devices but are still under debate due to the lack of experimental studies. In this talk, I will present polarized neutron diffraction and inelastic neutron scattering measurements performed onMn3Ge to gain insight into its magnetism. I will show Mn3Ge has an anti-chiral spin structure with a pe- culiar field dependence. I will also propose a spin Hamiltonian for this material that can explain its magnetic ground state selection and can also parametrize it’s spin wave excitations. [1] Nakatsuji S. et al., Nature 527.7577 (2015).
T3-5 Superconductivity (DCMMP) | Supraconductivité (DPMCM) / 2760
Hydride Superconductors, a path to room temperature supercon- ductivity
Author: Thomas Timusk1
1 McMaster University
The discovery of a superconducting phase in sulfur hydride under high pressure with a criticaltem- perature above 200 K by Drozdov et al. [1] has provided a new impetus to the search for even higher Tc. The observation of a sharp drop in resistance to zero at Tc, its downward shift withmagnetic field and a Meissner effect confirm superconductivity but the mechanism involved remains tobede- termined. Using the AILES beam line at Soleil, we provided a first optical spectroscopy study of this new superconductor[2]. Experimental results for the optical reflectivity of H3S, under high pressure, were compared with theoretical calculations based on Eliashberg theory using DFT results for the
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electron-phonon spectral density. One significant features stands out: a band with a depressed re- flectance in the superconducting state in the region from 450 meV to 600 meV. The shape, magnitude, and energy dependence of this band at 150 K agrees with our calculations. This is strong evidence of a conventional electron-phonon mechanism. Also, this band provides a tool for a non-invasive probe of superconductivity[3].
1. A.P. Drozdov, M.I. Eremets, I.A. Troyan, V. Ksenofontov, and S.I. Shylin, Nature 525, 73–76 (2015). 2. F.Capitani, B. Langerome, J.-B. Brubach, P. Roy, A. Drozdov, M.I. Eremets, E. J. Nicol, J. P. Carbotte, and T. Timusk, Nature Physics 15, 859 (2017) 3. J.P. Carbotte, E.J. Nicol, and T. Timusk, Physical Review Letters, 121, 047002 (2018)
M1-3 Magnetism and Heavy Fermions I (DCMMP) I Magnétisme et fermions lourds I (DPMCM) / 2761
From Quantum Spin Ice to Ordered Spin Ice in the Pyrochlore Tb2Ge2O7
Author: Alannah Hallas1
1 Department of Physics and Astronomy and SBQMI, University of British Columbia
Corresponding Author: [email protected]
The rare earth pyrochlores family of materials that are renowned for the diversity and novelty oftheir magnetic ground states. However, despite more than 20 years of effort, a consensus on the nature of the magnetic ground states of the terbium pyrochlores has remained elusive. Indeed, there are numerous confounding factors that come into play in these materials, including: a low-lying crystal electric field level, multipolar interactions, and magnetoelastic coupling. In my talk, I will introduce one member of this family, Tb2Ge2O7, and elucidate its phase behavior using heat capacity and neutron scattering measurements. We find that the magnetic state of Tb2Ge2O7 evolves througha complex series of transitions, starting from a correlated paramagnet, passing through a short-range ordered state that I will discuss in the context of quantum spin ice, and culminating in a fully long- range ordered spin ice state.
T2-5 Quantum magnetism (DCMMP) | Magnétisme quantique (DPMCM) / 2762
Magnetic Excitation Spectrum of a Coulomb Spin Liquid
Author: Kemp Plumb1
1 Brown University
Corresponding Author: [email protected]
Conventional magnets are characterized by symmetry breaking and the formation long-range mag- netic order at low temperatures. New and unanticipated phases of matter can arise when such symmetry breaking is inhibited by highly frustrated magnetic interactions. A spectacular example of this is the pyrochlore lattice with isotropic antiferromagnetic interactions, where the collective behavior of fluctuating magnetic moments is described by an emergent divergence free field.The microscopic magnetic degrees of freedom continue to fluctuate even at zero temperature, as if in a liquid state, but all configurations must obey the divergence condition; hence, this phase is termed a Coulomb spin liquid. In this talk, I will discuss a new pyrochlore lattice mag- net, NaCaNi2F7, which realizes the isotropic Coulomb spin liquid with S=1 spins. I will present neutron scattering and calorimetric measurements that were used to uncover the magnetic correla- tions in this material and determine the magnetic Hamiltonian. Na+ - Ca2+ are randomly populated
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in the crystal structure of NaCaNi2F7 creating a rugged energy landscape that acts to freeze a small fraction of the magnetic degrees of freedom. However, the energy scale set by this disorder is small, and the Heisenberg interactions prevail. Only a small fraction of the available moment is frozen, and the magnetism in NaCaNi2F7 is dominated by a persistently fluctuating component that ap- pears as a broad continuum of magnetic signal in inelastic neutron scattering measurements. These measurements demonstrate a beautiful realization of the Coulomb spin liquid and provide new in- sight into the interplay between disorder and magnetic exchange interactions in highly frustrated magnets.
T2-5 Quantum magnetism (DCMMP) | Magnétisme quantique (DPMCM) / 2763
Quantum magnetism on a chip
Author: Richard Harris1
1 D-Wave Systems
Corresponding Author: [email protected]
D-Wave Systems produces superconducting quantum processing units (QPUs) that instantiate the quantum annealing algorithm for solving hard optimization problems. However, these QPUs have also proved to be an interesting platform for studying quantum magnetism within the context of the so-called transverse field Ising model. Recent publications have shown how such QPUs can be used to study paramagnetic-to-spin glass phase transitions and Kosterlitz-Thouless physics as a function of the transverse, or quantum mechanical, degree of freedom in this model. This lecture will provide a brief review of these latter studies and a discussion of ongoing work related toquantum magnetism.
M1-11 Probing and controlling matter with light I (DCMMP) | Sonder et contrôler la matière avec de la lumière I (DPMCM) / 2764
Influence of Rashba effect on carrier kinetics in hybrid perovskites
Author: Kimberley Hall1
1 Dalhousie University
Corresponding Author: [email protected]
Owing to their large spin-orbit coupling [1], the lead halide hybrid perovskites are of interest for ap- plications in semiconductor spintronics and spin-optoelectronics. While the photophysical proper- ties of these materials have been studied extensively in recent years due to their potential for solution- processed, high-efficiency photovoltaic applications [2], much less is known about their spin-related properties [3-6]. Our studies of the spin-dependent carrier kinetics in butylammonium methylammo- nium lead iodide perovskite [7] indicate dominant precessional spin relaxation tied to the Rashba ef- fect. Our recent measurements of the coherent carrier kinetics in 3D CH3NH3PbI3also suggest a role played by the Rashba splitting on the rate of interband dephasing. These findings point to the need for further studies of the influence of the strong spin-orbit coupling on the charge and spin dynamics in this family of materials. [1] M. Kepenekian and J. Even, J. Phys. Chem. Lett. 8, 3362 (2017). [2] https://www.nrel.gov/pv/assets/images/efficiency_chart.jpg. [3] D. Giovanni et al. Nano Lett. 15, 1553 (2015). [4] C. Zhang et al. Nat. Phys. 11, 427 (2015). [5] P. Odenthal et al. Nat. Phys. 13, 894 (2017).
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[6] D. Niesner et al. Phys. Rev. Lett. 117, 126401 (2016). [7] S. B. Todd et al. arXiv:1807.10803 (2018).
T3-5 Superconductivity (DCMMP) | Supraconductivité (DPMCM) / 2765
From Mott to not: phenomenology of overdoped cuprates
Author: David Broun1
1 Simon Fraser University
Corresponding Author: [email protected]
Recently, the long-standing notion that the overdoped cuprate superconductors conform to a Landau- BCS description has been challenged strongly by new data on superfluid density and optical conduc- tivity of high quality LSCO films. We show instead that a wide variety of experimental data onLSCO and Tl2201 (superfluid density, optics, heat capacity, thermal conductivity) can be explained bydirty d-wave theory, subject to significant Fermi-liquid renormalizations, provided that the starting point is an accurate parameterization of the electronic dispersion, and the sometimes nonintuitive effects of disorder are properly treated. Our conclusions have important implications for future research on overdoped materials, and the overall understanding of cuprate physics.
W2-7 Condensed Matter Theory I (DCMMP) | Théorie de la matière condensée I(DPMCM) / 2766
Strange metallic transport in the doped Hubbard model
Author: Edwin Huang1
1 Stanford University
Corresponding Author: [email protected]
Strange or bad metallic transport, defined by its incompatibility with conventional quasiparticle pic- tures, is a theme common to strongly correlated materials and ubiquitous in many high temperature superconductors. The Hubbard model represents a minimal starting point for modeling strongly cor- related systems. Here we demonstrate strange metallic transport in the doped two-dimensional Hub- bard model using determinantal quantum Monte Carlo calculations. Over a wide range of doping, we observe resistivities exceeding the Mott-Ioffe-Regel limit with linear temperature dependence. The temperatures of our calculations extend to as low as 1/40 the non-interacting bandwidth, placing our findings in the degenerate regime relevant to experimental observations of strange metallicity. Our results provide a foundation for connecting theories of strange metals to models of strongly correlated materials.
T3-5 Superconductivity (DCMMP) | Supraconductivité (DPMCM) / 2776
Exploring the pseudogap critical point of cuprate superconduc- tors
Author: Nicolas Doiron-Leyraud1
Co-authors: S. Badoux 2; F Laliberté 2; C. Collignon 2; G. Grissonanche 2; E Lefrançois 2; B. Michon 2; A. Gorgout 2; A. Ataei 2; L. Taillefer 2; C. Proust 3; C. Marcenat 4; T. Klein 5
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1 Institut Quantique, Université de Sherbrooke 2 Département de Physique & Institut Quantique, Université de Sherbrooke 3 Laboratoire National des Champs Magnétiques Intenses (CNRS, EMFL, INSA, UGA, UPS) 4 Univ. Grenoble Alpes, CEA, INAC, PHELIQS, LATEQS 5 CNRS, Institut Néel
Corresponding Author: [email protected]
Unexplained to this day, the mysterious pseudogap phase of cuprate high-temperature supercon- ductors is one of their key defining universal properties. Many scenarios have been proposed for its origin, but none has provided a satisfactory description so far. Part of the problem stems from the absence of a clear and sharp signature of the pseudogap at low temperatures in the vicinity of its critical point at p. Here I will discuss our recent transport and thermodynamic measurements on a range of cuprate materials, which show that p is a quantum critical point. I will also show that hydrostatic pressure can be used as a tuning parameter for p* in Nd-LSCO, which puts constraints on theories of the pseudogap. Finally, I will mention very recent thermal Hall effect measurements that reveal a giant effect specific to the pseudogap phase and which seem to arise from neutral excitations.
R2-6 Topological and 2D materials (graphene, etc) (DCMMP) | Matériaux topologiques et 2D (graphène, etc.) (DPMCM) / 2777
When Molecules Met 2D Materials: Hybrid van der Waals Het- erostructures
Author: Emanuele Orgiu1
1 Institut national de la recherche scientifique (INRS), EMT Centre
The rise of 2D materials makes it possible to form heterostructures held together by weak interplanar van der Waals interactions. The incorporation of organic molecules within these systems holds an immense potential. Whilst nature offers a finite number of 2D materials, an almost unlimited variety of molecules can be designed and synthesized with predictable functionalities. The possibilities offered by systems in which continuous molecular layers are interfaced with inorganic 2Dmaterials to form hybrid organic/inorganic van der Waals heterostructures will be emphasized during the talk. Moreover, specific molecular groups can be employed to modify intrinsic properties and impartnew functionalities to 2D materials. In particular, molecular self-assembly at the surface of 2D materials can be mastered to achieve precise control over position and density of (molecular) functional groups, paving the way for a new class of hybrid functional 2D materials.
R1-3 Condensed Matter Theory II (DCMMP) | Théorie de la matière condensée II (DPMCM) / 2778
The magnon-mediated attraction between two holes doped ina CuO2 layer
Author: Mona Berciu1
1 University of British Columbia
Corresponding Author: [email protected]
We study a realistic three-band model for two holes doped into a CuO2 layer, using a variational method that allows us to turn on/off the exchange of magnons between the holes. This enables us to verify that the magnon-mediated effective hole-hole interaction is attractive and could therefore indeed be (part of) the superconducting glue. We derive its analytical expression and show that
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it consists of a novel kind of pair-hopping+spin-exchange terms. The coupling constant is fitted to numerical results obtained with the variational exact diagonalization. For realistic parameter values, this effective interaction is borderline strong enough to bind the holes into a pre-formed pair.
M2-5 Nuclear Structure I (DNP) | Structure nucléaire I (DPN) / 2779
Ab initio exploration of 12C
Author: Anna McCoy1
1 TRIUMF
Corresponding Author: [email protected]
Obtaining accurate predictions of nuclear structure starting from the interaction between constituent protons and neutrons is a complex, computationally demanding problem. Accurate predictions de- pend on both short-range correlations as well as long-range clustering and collective dynamics, par- ticularly when describing resonances and continuum states. We present state of the art methods used to obtain predictions of properties of both bound states and resonances in 12C with nuclear interactions from chiral effective field theory as the only input.
T3-1 Soft Matter PM-1 (DCMMP) | Matière molle PM-1 (DPMCM) / 2787
Stress in a Polymer Brush
Authors: M. Manav1; M. Ponga1; A.S. Pahani1
1 University of British Columbia
A brush-like structure emerges from the stretching of long polymer chains, densely grafted on to the surface of an impermeable substrate. This structure arises from a competition between the entropic elasticity of grafted polymer chains, and the intra and interchain excluded volume repulsion. Classi- cal studies on polymer brushes focus on the structure of a brush, monomer density, end-distributions etc. but not on the stress. Recent advances in polymer-brush based soft active materials required us to understand the nature of stresses and forces in these material systems. In this talk two strong stretching theories (SST), based on Gaussian and Langevin elasticity of chains, are compared and contrasted with Molecular Dynamics calculations. Continuum mechanics plays a fundamental role in providing the analytical and semi-analytical theoretical methods to evaluate stress and its distribu- tion within polymer brushes. For Gaussian chains, our theory predicts that the normal stress, parallel to the substrate, is a quartic function of the distance from the grafting surface with a maximum at the grafting surface. Idealizing the brush as a continuum elastic surface layer with a residual stress, closed form expressions for resultant surface stress and surface elasticity as a function of molecular weight and graft density are obtained. For higher graft density brushes, a (semi) analytical SSTwith Langevin chain elasticity will be discussed. Theoretical predictions are assessed by molecular dy- namics simulation of a brush using bead-spring model. Experimental estimation of resultant stress due to a polymer brush will also be discussed. We conclude that classical scaling theories as well as the SST theories can be coupled with continuum mechanics to understand stress in a polymer brush.
T2-1 Soft Matter AM-2 (DCMMP) | Matière molle AM-2 (DPMCM) / 2788
Non-equilibrium response of a strongly coupled rotary motor
Page 193 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Authors: Emma Lathouwers1; Joseph Lucero1; David Sivak1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
Living systems at the molecular scale are complex (composed of many constituents with strong and heterogeneous interactions), far from equilibrium, and subject to strong fluctuations. Energy conversion in such contexts would seem to be challenging, yet nature has evolved numerous molec- ular machines that efficiently, precisely, and rapidly transduce free energy between non-equilibrium reservoirs. Here we discuss design principles for effective free energy transduction in a simple model of FoF1 ATP synthase, a rotary motor that is crucial for virtually all living things. In particular, we discuss the interplay between non-equilibrium driving forces, natural equilibrium fluctuations, and interactions between the strongly coupled sub-systems that comprise the full machine.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2789
Spacetime thermodynamics and Weyl rescaling
Author: Fayçal Hammad1
1 Bishop’s University
Corresponding Author: [email protected]
A lot can be learned about spacetime by rescaling it à la Weyl. The familiar analogy between the laws of black hole mechanics and thermodynamics becomes ambiguous under such a rescaling. The deep reason for such an issue goes back to the fundamental dichotomy between matter and geome- try inherent in Einstein equations. This dichotomy is actually so fundamental that the issue extends beyond black hole thermodynamics, affecting the more general theme of spacetime thermodynam- ics.
T2-10 Nuclear Instrumentation (DNP) | Instrumentation nucléaire (DPN) / 2790
Investigation of the A=7 systems within the No-Core Shell Model with Continuum
Author: Matteo Vorabbi1
1 TRIUMF Canada’s particle accelerator centre
Corresponding Author: [email protected]
One of the recently developed approaches capable of describing both bound and scattering states in light nuclei simultaneously is the No-Core Shell Model with Continuum (NCSMC). This technique represents a state-of-the-art ab initio approach and combines the No-Core Shell Model (NCSM) de- scription of short-range correlations with the clustering and scattering properties of the Resonating Group Method. Recent NCSMC calculations of 7Be and 7Li will be presented. The properties of these nuclei were investigated by analyzing the continuum of all the binary mass partitions involved in the creation of these systems, using chiral interactions as the only input. Our calculations reproduce all the experimentally known states in the correct order and predict new possible resonances with negative and positive parity. A positive-parity S wave resonance is found analyzing the continuum of p + 6He at a very low energy above the threshold, which produces a very pronounced peak in the astrophysical S factor of the 6He(p,γ)7Li radiative capture. Possible implications for astrophysics have still to be investigated.
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DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2791
26 - Etude des propriétés thermochromes des couches minces de VO2
Authors: Adil Driouach1; B. Abdel Samad2; Komi Kougblenou1; pandurang V. Ashrit3
1 Assistant de recherche 2 Professeur 3 Professeur encadreur
Corresponding Authors: [email protected], [email protected], [email protected], bas- [email protected]
Les matériaux thermochromes sont ceux qui subissent un changement brusque de premier ordre de leurs propriétés optiques à une température spécifique. Un tel matériau thermochrome très connu est le VO2, il présente un intérêt scientifique et industriel majeur. En effet, les couches de VO2sont des semi-conducteurs transparents dans l’infrarouge à une température ambiante et passent à un état métallique hautement réfléchissant à une température de transition de 68 ℃. Cette transition de phase s’accompagne également de brusques changements électriques et structurels dans le matériau. Par conséquent, le matériau offre de nombreuses applications impliquant un commutateur depro- priété électrique et optique en fonction de la chaleur. De plus, travailler avec le VO2 sous sa forme de film mince offre le grand avantage d’adapter ses nombreux paramètres optiques ainsi que les aspects de commutation thermochrome à de diverses applications de gestion de chaleur. Dans le présent travail, l’objectif est d’étudier les revêtements sélectifs solaires nanostructurés du VO2 puis les effets de la chaleur et du froid sur le système. Pour ce faire, nous avons déposé leVmé- tallique sur un substrat de verre par la technique de pulvérisation cathodique. Le film du vanadium est recuit dans un four à vide pour former une couche du VO2. Les propriétés optiques, électriques et morphologiques de cette couche sont étudiées en détails. On a également étudié la commutativité de ces propriétés en fonction de la température. Les résultats montrent qu’une telle couche a le potentiel d’application pour une meilleure gestion de la chaleur.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2792
48 - Building a Portable, Cold-Atom Pressure Standard
Author: Perrin Waldock1
Co-authors: Kirk Madison 2; Pinrui Shen 3; James Booth 4
1 UFV 2 UBC 3 University of British Columbia Physics Department 4 BCIT
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Vacuum measurement plays a central role in a wide range of scientific and industrial applications including residual gas analysis, semi-conductor device manufacture, and atmospheric modeling. Re- markably, no primary pressure standard existed for the high (HV) and ultra-high vacuum (UHV) regime (below 10−7 Pa) until recently. In 2018, a UBC and BCIT collaboration succeeded in pro- ducing the first primary pressure standard for HV and UHV. Based on a cold-atom sensor, thisnew technique for particle detection requires no calibration and relies on immutable laws of nature - specifically, the interaction potentials between atoms and molecules. The existing cold-atom stan- dard is immobile and the size of several refrigerators; to see wide use and to promote worldwide
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adoption, an apparatus must be shippable, and usable in non-ideal conditions by non-experts. To re- alize this, we are assembling a miniaturized version of the apparatus, that will be robust to vibrations, mechanical shock, and temperature changes. We will also investigate methods of automatically op- erating and re-calibrating the apparatus. This device will allow us to disseminate the cold-atom pressure standard worldwide starting with a plan to compare the cold atom primary standard with an existing secondary pressure standard (based on orifice-flow) at the National Institute of Standards and Technology. This work will also lay the groundwork for the construction of commercial absolute pressure standards.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2793
40 - Propriétés optiques et électriques des couches minces du VO2
Authors: Adil Driouach1; Komi Kougblenou1; Bassel Abde Samad 2; Pandurang V Ashri3
1 Assistant de recherche 2 Professeur 3 Professeur (encadreur)
Corresponding Authors: [email protected], [email protected], [email protected], pan- [email protected]
Le dioxyde de vanadium (VO2 ) est un matériau thermochrome intéressant de la famille des oxy- des de métaux de transition (”OMT” ). Il est caractérisé par une température de transition (Tt = 68 ℃) réversible. Parmi les “OMT” , le VO2 est celui dont la température de transition (Tt) est la plus proche de la température ambiante. C’est un semi-conducteur en dessous de cette température et métallique au-dessus de celle-ci. En traversant la température de transition, on observe des change- ments brusques dans les propriétés optiques et électriques de ce matériau. On observe également une hystérésis dans ces propriétés en fonction de la température. Tous ces changements impor- tants rendent le VO2 intéressant non seulement d’un point de vue théorique, mais aussi pour des applications. On peut envisager des applications tels que les fenêtres intelligentes, les composantes électro-optiques, etc. Dans le cadre de notre travail, nous avons fabriqué et caractérisé les couches de VO2 en fonction de l’épaisseur de la couche. La fabrication des couches par la méthode de couplage pulvérisation- oxydation passe par deux étapes : déposition de vanadium pur dans un système à vide, et ensuite oxyder la couche par un traitement thermique contrôlé dans un four à vide. Les propriétés optiques et électriques de ces couches ainsi que l’hystérésis de ces propriétés ont été étudiées systématique- ment en fonction de leur épaisseur. Les résultats de ces travaux montrent une dépendance forte des propriétés thermochromes de VO2 sur l’épaisseur. Ces connaissances pourront nous aider à mieux optimiser les dispositifs thermochromes pour des différentes applications
T3-2 Novel Magnetic Fusion Configurations (DPP) | Nouvelles configurations de fusion mag- nétique (DPP) / 2794
The Field-Reversed Configuration as a Practical Fusion Reactor Core
Author: Edward DeWit1
Co-author: Jordan Morelli 1
1 Queen’s University
Page 196 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Authors: [email protected], [email protected]
The field-reversed configuration (FRC) is a class of magnetically confined plasmas characterized by self-generated poloidal fields and no toroidal fields. The FRC has a high beta value, the ratio ofplasma pressure to magnetic field pressure, which means that the required strength of the external magnetic field is much lower when compared to other magnetic confinement schemes. Consequently, the achievable temperatures are much higher, which leads to the possibility of aneutronic fusion. The FRC has other technical benefits that make it a practical means to achieve nuclear fusion includ- ing simple linear geometry, and natural diverter systems for particle extraction and direct energy conversion. In this talk, I will discuss the technical benefits of the FRC as a practical fusion reactor core. I will also present the current research being performed in this area, the role of Canada in the worldwide fusion programme, and an outlook to the future of magnetic confinement fusion.
DPP Poster Session & Student Poster Competition Finals (7) | Session d’affiches DPP et finales du concours d’affiches étudiantes (7) / 2795
20 - Mitigation of the Rotational Instability of the Field-Reversed Configuration via Edge-Biasing
Author: Edward DeWit1
Co-author: Jordan Morelli 1
1 Queen’s University
Corresponding Authors: [email protected], [email protected]
The rotational instability of the field-reversed configuration (FRC) has been shown to severely reduce the lifetime of the confined plasma. FRC plasmas have strong rotational modes from the electric drift and the ion-diamagnetic drift. Their nonlinear growth can cause plasma to scrape against thewall, resulting in loss of particles and energy. Edge-biasing refers to applied external fields that modify the rotation in the edge-layer of the plasma. By driven toroidal flow shear, the internal plasma is affected by the rotation in the edge-layer, which leads to improved stability, longer plasma lifetime, and better confinement. This poster will present the basic theory of the FRC plasma and thedesign of an FRC plasma confinement chamber suitable for nuclear fusion. In particular, the design ofedge- biasing electrodes will be presented in detail, along with a description of plasma diagnostics useful for demonstrating FRC plasma stability and confinement.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2796
Nuclear kinetic density from ab initio theory
Author: Michael Gennari1
Co-authors: Petr Navratil 1; Matteo Vorabbi 2
1 TRIUMF 2 TRIUMF Canada’s particle accelerator centre
Corresponding Authors: [email protected], [email protected], [email protected]
The nuclear kinetic density is a fundamental, non-observable quantity in density functional theory (DFT) dependent on the nonlocal nuclear density. With the ability to compute the nonlocal nuclear density in the ab initio no-core shell model approach (NCSM), we may provide insights about nu- clear structure by comparing center of mass (COM) removal procedures, which can improve the precision of density functionals. We derive the kinetic density from the nonlocal one-body nuclear density computed in the NCSM. We construct translational invariance in our nuclear density, and
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hence kinetic density, by exactly removing the spurious COM component from the NCSM eigen- states expanded in the harmonic oscillator (HO) basis. The ground state nonlocal nuclear density and kinetic density of 4,8He, 12C, and 16O are calculated to display the effects of COM removal on predicted nuclear structure. The results of this work have been published in Phys. Rev. C 99,024305 (2019).
R2-4 Testing Fundamental Symmetries II (DTP/PPD/DNP) | Tests de symétries fondamentales II (DPT/PPD/DPN) / 2797
EDMs and Dark Sectors
Author: Adam RitzNone
Corresponding Author: [email protected]
Precision measurements of electric dipole moments (EDMs) of the neutron, atoms and molecules constitute important tests for new sources of CP violation in nature. Given the empirical motiva- tion for new physics in a hidden (or dark) sector, notably arising from the need to explain dark matter and neutrino, I’ll discuss the implications of this scenario for EDM measurements andthe complementarity with direct probes of dark sectors.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2798
Structure of 188Hg From Gamma-ray Spectroscopy With GRIF- FIN
Author: Andrew MacLean1
Co-authors: F. A. Ali 2; C. Andreoiu 3; G. C. Ball 4; N. Bernier 5; H. Bidaman 6; V. Bildstein 6; M. Bowry 4; R. Caballero-Folch 4; A. Varela Diaz 6; I. Dillmann 7; M. R. Dunlop 6; R. Dunlop 6; A. B. Garnsworthy 4; P. E. Garrett 6; G. Hackman 4; B. Jigmeddorj 6; A. I. Kilic 6; A. T. Laffoley 6; H. P. Patel 4; B. Olaizola 8; Y. Saito 5; J. Smallcombe 4; J. K. Smith 9; C. E. Svensson 6; J. Turko 6; K. Whitmore 3; T. Zidar 6
1 University of Guelph 2 Department of Physics, University of Guelph, Guelph, ON, and Department of Physics, University of Sulaimani, Kurdistan Region, Iraq 3 Department of Chemistry, Simon Fraser University, Burnaby, BC 4 Physical Sciences Division, TRIUMF, Vancouver, BC 5 Physical Sciences Division, TRIUMF, Vancouver, BC and Department of Physics, University of British Columbia, Vancouver, BC 6 Department of Physics, University of Guelph, Guelph, ON 7 Physical Sciences Division, TRIUMF, Vancouver, BC and Department of Physics, University of Victoria, Victoria, BC 8 Physical Sciences Division, TRIUMF, Vancouver, BC, 9 Department of Physics, Reed College, Portland, Oregon
Corresponding Author: [email protected]
Neutron deficient nuclei near Z=82 exhibit one of the most extensive manifestations of shape coex- istence across nuclear chart [1]. In the even-even mercury isotopes, 182−188Hg, Coulomb excitation experiments have provided a sensitive probe to determine the E2 matrix elements, giving informa- tion on the nature of the deformation for nuclear states [2]. Precise measurements of absolute and relative B(E2) values for transitions between the shape-coexisting states also provide important in- formation on their mixing [2,3].
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For ∆J ≠ 2 transitions between states of the same parity, the determination of B(E2; Ji → Jf ) val- ues depends on the E2/M1 mixing ratios, δ. Precise measurements of these mixing ratios, however, are often challenging. One of the best methods to extract the mixing ratios isthrough γ − γ angular correlation measurements following EC/β decay where a very high sensitivity can be achieved. We have recently adopted this technique for the GRIFFIN γ-ray spectrometer, located at the ISAC facil- ity at TRIUMF, and have applied it to measurements of the EC/β decay of 188−200mTl to 188−200Hg. Also Included in this measurement was the PACES array, used for the detection of conversion elec- trons to determine E0 transition strengths. Our first results, for 188Hg indicate the dominance of the E2 components in the J → J transitions. In addition to enabling the determination of the B(E2) values, knowledge of these mixing ratios are also critical for the extraction of E0 components which may be enhanced if there are significant mixings between the shape-coexisting configurations. Results on angular correlation measurements and E0 transition strengths for 188Hg will be presented. [1] K. Heyde, J. L. Wood, Rev. Mod. Phys. 83, 1467(2011). [2] N. Bree et al. Phys. Rev. L 112, 162701(2014). [3] L. Gaffney et al., Phys. Rev. C 89, 024307 (2014).
T1-4 Direct Detection of Dark Matter (PPD) | Détection directe de la matière sombre (PPD) / 2799
The PICO Experiment
Author: Ken Clark1
1 Queen’s University
Corresponding Author: [email protected]
The PICO collaboration uses bubble chambers to search for dark matter with results leadingthe world in sensitivity to the direct detection of WIMPs with spin-dependent coupling to protons. PICO recently operated a 32 litre bubble chamber (PICO-60) at the SNOLAB underground laboratory and the next generation experiment is currently taking commissioning data. This new device (PICO-40L) will prove the viability of the “right side up” design and demonstrate the possibility of scaling up to the next ton-scale experiment (PICO-500, currently being designed). A discussion of the technology, recent results, and future plans will be presented.
T2-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria AM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria AM-2 (DPN) / 2800
Creative Chemistry and Cyclotrons: Training students and ex- panding the toolbox of PET radionuclides
Author: Suzanne Lapi1
1 University of Alabama at Birmingham
Corresponding Author: [email protected]
With the expansion of approved 18F based agents for medical imaging using positron emission to- mography (PET), low energy (11-24 MeV) cyclotrons are now used at many commercial and academic centers to produce isotopes for medical imaging. The energy of these machines is ideal for isotope production via (p,n), (p,α) and in some cases (p,2n) reactions. These sites also provide ideal training grounds for the next generation of nuclear and radiochemists. Using the UAB TR24 cyclotron, our
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group has focused on the development of reaction routes, target materials and the separation chem- istry of isotopes to expand the toolbox of nuclear imaging agents. These have included transition metals such as 52Mn, 55Co, 89Zr, 43,47Sc and 45Ti. Additional research has developed chemistry to incorporate these isotopes into new imaging radiopharmaceuticals for preclinical or clinical research. In particular, our group has been exploring the use of 89Zr radiolabeled antibodies for imaging of cell surface receptor expression in preclinical models and in clinical trials of metastatic breast cancer patients. Recent work has also resulted in new radiochemistry techniques for the development of new 43,47Sc and 45Ti radiopharmaceuticals for oncologic applications.
T2-4 Indirect and collider searches for dark matter (PPD) | Recherches indirectes et par colli- sionneurs pour la matière sombre (PPD) / 2801
Dark Matter Searches with VERITAS
Author: Stephan O’Brien1
1 McGill University
Corresponding Author: [email protected]
Dark matter is the dominant matter component of the universe. Despite its dominance overbary- onic matter, the true nature of dark matter in unknown. One dark matter candidate istheweakly interactive massive particle (WIMP), invoked in several extensions to the Standard Model. The self- annihilation or decay of WIMP particles in regions of high dark matter density can produce sec- ondary Standard Model particles such as very-high-energy (VHE, E> 100 GeV) gamma rays, allowing for indirect detection of dark matter. Indirect searches can be performed by making VHE observa- tions of astrophysical regions of high dark matter density. As part of its long-term plan, VERITAS, a ground-based gamma-ray observatory sensitive to gamma rays in the ~85 GeV to greater than 30 TeV energy range, has observed a number of these regions. These observations have yielded con- straints on the annihilation cross section of dark matter particles. In this talk I will discuss VERITAS observations of dark-matter-rich regions, such as dwarf spheroidal galaxies and the Galactic Centre, in the context of indirect dark matter searches.
T2-10 Nuclear Instrumentation (DNP) | Instrumentation nucléaire (DPN) / 2802
Decay studies using the GRIFFIN Spectrometer at TRIUMF-ISAC
Author: Ryan Dunlop1
1 Department of Physics, University of Guelph, Guelph, ON
The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) at TRIUMF- ISAC provides unique opportunities for decay studies with rare-isotope beams. GRIFFIN is located in the ISAC-I facility at TRIUMF and comprises 16 high-efficiency Compton-suppressed HPGe clover detectors. GRIFFIN is complemented by a suite of ancillary detector systems that allow for compre- hensive studies of the decays of rare isotopes in order to investigate nuclear structure, nuclear astro- physics and perform tests of fundamental symmetries. An overview of the GRIFFIN spectrometer, along with selected highlights from the GRIFFIN research program will be presented.
M1-4 Mathematical Physics (DTP) | Physique mathématique (DPT) / 2803
Cuscuton Bounce
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Author: Ghazal Geshnizjani1
1 University of Waterloo/Perimeter Institute
Corresponding Author: [email protected]
In general relativity producing a regular bounce entails violation of Null Energy Condition for a dynamical source in the model. That generically indicates existence of ghosts or other instabilities. However, in cuscuton modification of gravity, the correspondence between a background bounce and violation of Null Energy Condition for dynamical sources is broken. Cuscuton action, modifies equations of motion in Infra Red limit allowing the background togo through a regular bounce phase. At the same time, since it does not contain any dynamical degrees of freedom, it does not lead to ghosts or other instabilities. Here, I present a toy scenario of a regular bouncing cosmology and prove this claim
W1-3 Topics in Medical Physics (DPMB) | Sujets de physique médicale (DPMB) / 2804
CNT-based composite to eliminate Chemical shift error in simul- taneous PET/MRI
Authors: Narjes Moghadam1; Roger LECOMTE2; Rejean Fontaine1
1 Université de Sherbrooke 2 Universite de Sherbrooke
Corresponding Authors: [email protected], [email protected], [email protected]
Simultaneous PET/ MRI scanner provides both anatomical and functional properties of malignant tissues concurrently, while avoiding uncertainty exists in sequential PET/MRI system. Electromag- netic interference (EMI) between two scanners is a big challenge which restricts both scanner per- formance and distorts the image quality of each modality. Although metals have excellent radio-frequency shielding properties to block the EMI, they are not a good candidate for shielding in presence of switching magnetic fields of MRI. Indeed, based on the Faraday’s law, variations of magnetic field induce eddy currents in any metallic layer, which have negative impact on the MR image quality and produce the chemical shift error. Thus, there is ahuge demand for a new shielding material without inducing eddy currents. We have extensively investigated the effects of gradient switching in different frequencies from10 kHz to 100 kHz) and with diverse pulse shapes on particular conductive material to find out the viable candidate for PET/MRI application. To estimate the eddy current in each conductive layer, a custom-made eddy current measurement set-up was fabricated, which evaluates the amount of induced magnetic field by monitoring the variation in voltage at the set-up. A layer ofcopper, aluminum, carbon fiber, graphene and CHO-SHIELD® 2056 paint were examined. Although there- sults for eliminating eddy current from paint and graphene were astounding, we could still observe variation in voltage less than 0.7%. Therefore, we fabricated a new composite based on carbon nan- otube (CNT) to have control over the shielding layer properties. The CNT based composite provides enough conductivity (about 1E5 S/m) to eliminate the low frequency gradient switching interfer- ences and its network shaped structure prevents the induction of eddy currents in our measurement set-up
T4-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-2 (DPN) / 2805
Canada’s DRAGON
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Author: Chris Ruiz1
1 TRIUMF
Corresponding Author: [email protected]
DRAGON is Canada’s Recoil Separator facility for Nuclear Astrophysics - a unique device in the world. Leveraging on previous decades of work with recoil separators at stable beam facilities, and new advances in radioactive ion beam technology, the positioning of DRAGON at TRIUMF- ISAC was a cutting-edge step to allow measurements of a ubiquitous type of nuclear reactionin stars: radiative capture, on short-lived exotic isotopes. John D’Auria was the Principal Investigator during the design, construction and initial experiments of the project, and led the group for many years until his retirement. In this talk I will present an overview of what DRAGON has accomplished over the years, and John’s contributions to it, which followed on from his work with radioactive beams at TISOL and his suc- cessful advocacy for the ISAC project.
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2806
Better motors, generators and transformers for electrical power
Author: Anthony S. Arrott1
1 Simon Fraser University
Corresponding Author: [email protected]
Current technology using polycrystalline electrical steels operates at a maximum magnetic induc- tion of 1.6 T. Here it is proposed to change this to greater than 2 T using patterned polycrystalline iron with energy savings approaching a trillion dollars per year. Such a fundamental change in tech- nology may take a generation. It is proposed to use the proceeds from this endeavor to give clean drinking water to the world.
T3-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria PM-1 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria PM-1 (DPN) / 2807
Gamma-Ray Spectroscopy at the Limits
Author: Heather Crawford1
1 Lawrence Berkeley National Laboratory
Corresponding Author: [email protected]
The study of nuclei far from stability is one of the most active and challenging areas of nuclear struc- ture physics. Studies of the most exotic neutron-rich isotopes require an unprecedented combination of beam intensities and detection sensitivity, which will soon be realized in the United States at the Facility for Rare Isotope Beams, with γ-ray spectrometers such as GRETA. The GRETINA array, being operated at NSCL and ATLAS at ANL is already pushing forward the limits of such measure- ments, with impacts in basic nuclear structure, nuclear astrophysics and applications. I will present an overview of the program of GRETINA/GRETA and highlight a few examples of the compelling physics being pursued.
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T1-3 Nuclear Structure II (DNP) | Structure nucléaire II (DPN) / 2808
The CANREB Project for Charge State Breeding at TRIUMF
Author: Leigh Graham1
1 TRIUMF
Corresponding Author: [email protected]
ISAC is the ISOL facility at TRIUMF where rare isotope beams for use in nuclear reaction investi- gations are created by bombarding solid targets with high energy particle beams. TRIUMF is en- hancing its rare isotope production capabilities through a new scientific infrastructure known as the Advanced Rare IsotopE Laboratory (ARIEL). The low-energy transport section of the ARIEL expan- sion is known as CANREB (CANadian Rare-isotope facility with Electron-Beam ion source) which aims to increase the mass range of high purity beams available for further acceleration. To accomplish this the cocktail of ions from the solid target will be first sent through a high resolu- tion mass separator where most of the isobaric contaminations should be removed. The continuous beam of singly charged ions of interest will then be fed into an RFQ cooler buncher where pulses of typically 106 ions per bunch will be created before being transported to a pulse drift tube where the energy will be lowered to match that of the trap of the electron beam ion source (EBIS). Inside the trap of the EBIS the ions will be confined radially by a 6 T Helmholtz magnetic field and longitudinally electrostatically. They will then be charge bred through electron impact ionisation via interaction with an electron beam with a density of up to 20 000 A cm−2. It is required that a mass to charge ratio of less than 7 amu/e be reached within a repetition time of 10 ms to allow for operation with short lived isotopes. The highly charged ions extracted from the EBIS will then be traversed through a NIER spectrometer for mass selection before reaching the goal of post-acceleration.
T1-5/T1-7 Strong Correlations in Cold atoms (DAMOPC/DCMMP) | Corrélations fortes dans les atomes froids (DPAMPC/DPMCM) / 2809
Spin-dependent superfluidity in ultracold BECs
Author: Lindsay LeBlanc1
Co-authors: Logan Cooke 1; Benjamin Smith 1; Taras Hrushevskyi 1
1 University of Alberta
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
The exquisite control available in ultracold quantum gas experiments has enabled the emulation of many different quantum systems and allowed us to better understand the many-body statesof quantum matter. Using the technique of artificial gauge fields, a spatially- and spin-dependent gauge potential Aσ(⃗r) can be engineered in a BEC, in which the kinetic energy is modified from the free- particle value to create spin-dependent artificial magnetic field, B. In the limit of strong-enough B, vortices should enter the system, but will have opposite circulation for each spin. This raises several questions: Can vortices of opposite rotation be introduced into the same condensate? Is the threshold for vortex nucleation the same as a single-component system? What are the stable spatial configurations of vortices? How do inter-spin interactions affect all of these? This talk willdiscuss the theoretical simulations of a spin-dependent artificial magnetic field, and discuss our progress towards realizing these gases using ultracold 87Rb atoms in our laboratory.
M1-8 Neutrinoless Double Beta Decay and Strangeness (DNP) | Double désintégration bêta sans neutrino et étrangeté (DPN) / 2810
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Recent progress on Strangeness Nuclear Physics at J-PARC
Author: Tomofumi Nagae1
1 Kyoto University
Corresponding Author: [email protected]
The K− beam intensity at the hadron experimental hall in J-PARC is steadily increasing for con- ducting strangeness nuclear physics program. The present production target in the hadron hall can accept up to ~50 kW proton beam from the 30-GeV main ring. In the summer of 2019, a new produc- tion target which can operate more than 80 kW is going to be installed, and the beam intensity will be increased more than 1 M/spill. In this talk, recent topics obtained in the following several experiments at J-PARC will be presented: 4 19 1) Hypernuclear gamma-ray spectroscopy in ΛHe and F (E13), 2) Hybrid emulsion experiment to look for double-Λ hypernuclei (E07), 3) Search for Ξ-hypernucleus in the 12C(K−,K+) reaction (E05), and 4) Search for K-pp bound state in 3He(K−, Λp)n reaction (E15). Further, future prospect of the strangeness nuclear physics program will be mentioned.
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2811
86 - Numerical Simulation of Biomagnetic Field from Somatosen- sory Evoked Response
Authors: Brittany NoneLu ; Lexis WongNone
Co-author: Matthew Courtemanche
Corresponding Authors: [email protected], [email protected], [email protected]
Optically-pumped atomic magnetometers (OPMs) have seen great advancements over the past years and emerge as a promising alternative to the superconducting quantum interference device (SQUID) detector system that is currently used in magnetoencephalography (MEG). OPMs are more affordable to manufacture, and its sensitivity at room temperature is comparable to that of the SQUID detectors. Without the need for cryogens or a dewar, OPMs can be placed closer to the scalp, enhancing the strength of the signal, and reducing noise. Unlike SQUID sensors, OPMs need not be situated in a shielded room from surrounding fields, allowing for lower maintenance MEG systems. Some ofthe studies utilising MEG currently done by our group include eye blink, auditory evoked response, and somatosensory evoked response. We would like to manufacture our own OPM sensors to replace the current SQUID sensors. To estimate the range of frequency wherein the OPM needs to operate, we will study the somatosensory evoked response (SEP), an electrical activity of the brain that is caused by physical stimulus. In particular, we will focus on median nerve and tibial nerve SEP, the former which delivers an electrical stimulus to the wrist, and the latter to the ankle. The propagation of an action potential resulting from the stimulus is approximated as currentim- pulses along the different nerve fibers. We numerically simulate the magnetic field of theaxonal current of different nerve fibres by modelling the axonal current as current dipoles. Ultimately, we want to create a numerical model of the bio-magnetic field in the human brain that results from stimulus, which would allow us to determine the frequencies of operation of the OPMs.
T2-8 Magnetic resonance imaging (DPMB) | Imagerie par résonance magnétique (DPMB) / 2812
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Accelerated Diffusion-Weighted Hyperpolarized 129Xe Gas Lung MRI
Authors: Fumin Guo1; Matthew Fox2; Grace Parraga3; Alexei Ouriadov4
1 Sunnybrook Research Institute, University of Toronto 2 Lawson Health Research Institute 3 Department of Medical Biophysics, Western University 4 The University of Western Ontario
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Hyperpolarized 3He/129Xe gas pulmonary MRI provides physiologically relevant biomarkers of ob- structive lung disease, including emphysema, bronchopulmonary dysplasia and alpha-1 antitrypsin deficiency (AATD). Recently, a stretched-exponential-model combined with under-sampling inthe imaging and diffusion direction was used to generate 3He static-ventilation (SV),T2, multiple b-value diffusion-weighted (DW) MRI ADC and morphometry maps, demonstrating an acceleration factor (AF) of 7 to 10. The low gyromagnetic ratio of 129Xe coupled with clinically used gradient strengths, dic- tate that rapid acquisition strategies be developed to facilitate clinical uptake of 129Xe DW imaging. We hypothesize that the 3He method can be adapted to provide whole lung 129Xe MRI-based emphy- sema biomarkers, including SV, T2, ADC and morphometry maps. Therefore, in this proof-of-concept study, our objective was to extend the 3He method for accelerated 129Xe lung morphometry using single breath measurements for validation in a small group of patients. Three healthy volunteers (<25yr>) and six AATD (<65yr>) patients provided written informed con- sent to participate in an ethics-board approved study protocol and underwent spirometry, plethys- mography, and accelerated 129Xe MRI morphometry using a single xenon dose. Imaging was per- formed at 3.0T using whole-body gradients and a commercial human-sized xenon quadrature flex RF coil. For xenon measurements the diffusion-sensitization gradient pulse ramp up/down time was 500μs, constant time=2ms and diffusion time=5.2ms, providing five b-values of 0, 12.0, 20.0, 30.0, and 45.5s/cm2. For accelerated acquisition, a multi-slice (six interleaves) centric 2D FGRE DW sequence under-sampled in the imaging and diffusion direction for seven 30mm coronal slices. An extra inter- leave without DW (b=0) with significantly reduced TE (2ms) was utilized to generate a short-TE SV image and T2map. A 7.4 degree constant-flip-angle (120 [20 per b-value] RF pulses-per-slice) was used for the AF=7 (all participants, 12sec single breath-hold) acquisitions. To the best of our knowledge this is the first demonstration of 129Xe MRI morphometry measurements with AF=7. We have demonstrated that accelerated 129Xe MRI morphometry permitted to generate whole lung SV, T2, ADC and morphometry maps within a single 12sec breath-hold with typical spa- tial resolution.
W2-8 Nuclear Astrophysics II (DNP) | Astrophysique nucléaire II (DPN) / 2813
Two-major shell-model effective Hamiltonian from in-medium similarity renormalization group approach
Authors: T. Miyagi1; J. D. Holt2; S. R. Stroberg3; N. Shimizu4
1 TRIUMF 2 TRIUMF 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada 3 U Washington 4 CNS, U Tokyo
Corresponding Author: [email protected]
In the past decade, many efforts have been made in the ab initio nuclear calculations. Nowadays, the capability of ab initio many-body calculations has reached to the mass number 100 region. The cal- culation methods which are available for the medium-mass region such as coupled-cluster method, self-consistent Green’s function method, and in-medium similarity renormalization (IM-SRG) are usually limited the applications to closed-shell nuclei. The combination of the IM-SRG and con- ventional shell-model calculation is one of the powerful tools to access the open-shell systems. In
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this framework, the effective Hamiltonian for the shell-model calculations is obtained through the IM-SRG so that the valence-space Hamiltonian is decoupled with the core and outside of the va- lence space. So far this framework was mainly applied for the single major-shell valence space problem. However, we obviously need the two (or multi) major-shell effective Hamiltonian to in- vestigate the unnatural parity states, excitation spectra for doubly magic nuclei (16O, 40Ca, …), and exotic region such as the island of inversion. In this talk, we will present how to calculate the two-major shell-model effective Hamiltonian in the IM-SRG framework and show the numerical results with them.
T2-3 Nuclear Astrophysics/Structure and Medical Isotopes in honour of Prof. John D’Auria AM-2 (DNP) | Astrophysique nucléaire / Structure et isotopes médicaux en hommage au prof. John D’Auria AM-2 (DPN) / 2814
Positron emission tomography (PET) contributions to a better un- derstanding of brain function
Author: Vesna Sossi1
1 University of British Columbia
Corresponding Author: [email protected]
Positron Emission Tomography imaging coupled with an increasingly target specific tracer devel- opment is providing key insights into brain function in health and disease. Multiple neurochemi- cal correlates to various brain diseases, mental states and personality traits have been uncovered. For example, multi-tracer imaging is revealing the impact of neurodegeneration, such as observed in Parkinson’s disease (PD), on several neurotransmitter systems and functional connectivity. At the same time there is an increasing awareness of the network type behavior of the brain and of the importance of the interactions between localized neurochemical alterations and longer-range functional effects. Distinct brain network-type behaviors are also being observed using functional magnetic resonance imaging (fMRI). This emerging knowledge highlights the importance of novel analysis approaches to the PET and/or multi-modality data which focus on identifying specific spatio- temporal patterns characteristics of brain function under different conditions. This talk will provide a brief history of how advances in imaging including radiotracer and instrumentation development as well as advances in data processing algorithms have contributed to revolutionize not only the understanding of brain function, but also the very concept of mental illness.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2815
41 - Controlled enantioselective orientation of chiral molecules with an optical centrifuge
Authors: Valery Milner1; Alexander Milner1; Jordan Fordyce1; Ian MacPhail-Bartley1; Walter Wasserman1; Ilia Tutunnikov2; Ilya Averbukh2
1 UBC 2 Weizmann Institute of Science
Corresponding Author: [email protected]
We initiate unidirectional rotation of chiral molecules with an optical centrifuge and detect their spatial orientation by means of Coulomb explosion imaging. We show that the centrifuge-induced orientation of one of the molecular axes in the laboratory frame depends on the relationship be- tween the chiral handedness of the enantiomer and the direction of the laser-induced molecular rotation. The effect is reproduced in the numerical simulations of the centrifuge excitation followed
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by Coulomb explosion of the centrifuged molecule. The demonstrated technique offers not only an alternative way of differentiating between molecular enantiomers, but also a new approach to enantioselective manipulation of chiral molecules with light.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2816
Optimization of nanoparticle transport using monolayer and mul- tilayer cell models
Author: Kyle Bromma1 Co-authors: Leah Cicon 1; Aaron Bannister 1; Devika Chithrani 1; Wayne Beckham 2
1 University of Victoria 2 Britich Columba Cancer Agency
Corresponding Authors: [email protected], [email protected], [email protected], de- [email protected]
High atomic number nanomaterials have been explored as a tool for improving cancer therapeutics. Gold nanoparticles are a system that has been introduced as they can act as effective radiation dose enhancers and anticancer drug carries. Gold nanoparticles have unique physiochemical properties that allow them to be probed in cells using techniques such as scanning electron microscopy and hyper spectral imaging. Optimization of gold nanoparticle uptake into 3D in-vitro models is essential to optimizing future cancer therapeutic applications and bridging the gap between in-vitro and in- vivo tumour environments. The optimization of the uptake of functionalized gold nanoparticles into 2D monolayer and 3D spheroid cell models was tested. Our initial findings reveal that smaller gold nanoparticles penetrate better vs larger gold nanoparticles within the 3D tumor models. This correlates very well with our recent in-vivo data. Hence, development of these 3D tissue models can be utilized to mimic tumor microenvironments in the lab, which would accelerate the use of gold nanoparticles in future cancer treatment.
T1-4 Direct Detection of Dark Matter (PPD) | Détection directe de la matière sombre (PPD) / 2817 questions
W2-3 Molecular Motors (DPMB) | Moteurs moléculaires (DPMB) / 2818
Operational Principles for the Dynamics of a Rolling Motor
Authors: Eldon Emberly1; Lavisha Jindal1
1 Simon Fraser University
Corresponding Authors: [email protected], [email protected]
Translocation of a ligand bound spherical cargo which is biochemically associated to a receptor bound substrate through a Burnt bridges ratchet mechanism is fundamentally altered if the cargo is capable of rolling. Directed rolling is an effective method for cargo translocation and arises only for specific ranges in parameter space of this system. In this study we present the dynamical principles of this class of motors and offer a comparison with conventionally studied motors that translocate
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without rolling. We observe the changes in the dynamics of the cargo as a function of the substrate properties (like stickiness, elasticity, spacing, concentration of receptors and valence) and the chem- istry between the cargo and the substrate (force of attraction, rate of receptor cleaving). We evaluate the dynamics of the rolling motor by computing two metrics: the correlation between translational displacement and rotational displacement and the ratio of the total displacement over total distance travelled by the cargo. Finally, we compare the dynamics with a cargo executing pure translational motion on the following basis relevant to motors: speed, detachment probability, persistence and processivity.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2819
58 - Dueling Dynamical Backaction in a Cryogenic Optomechan- ical Cavity
Author: Bradley Hauer1
Co-authors: Thomas Clark 1; Paul Kim 1; Callum Doolin 1; John Davis 1
1 University of Alberta
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
Dynamical backaction has proven to be a versatile tool in cavity optomechanics, allowing for precise manipulation of a mechanical resonator’s motion using confined optical photons. In my talk, Iwill present measurements of a silicon whispering-gallery-mode optomechanical cavity where backac- tion originates from opposing radiation-pressure and photothermal forces, with the former dictating the optomechanical spring effect and the latter governing the optomechanical damping. Athigh enough optical input powers, we show that the photothermal force drives the mechanical resonator into self-oscillations for a pump beam detuned to the lower-frequency side of the optical resonance, contrary to what one would expect for a conventional radiation-pressure-dominated optomechanical device. Using a fully nonlinear model, we fit the hysteretic response of the optomechanical cavity to extract its properties, demonstrating that this non-sideband-resolved device exists in a regime where photothermal damping could be used to cool its motion to the quantum ground state.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2820
66 - Calibrating an ultra-low bacground detector: DEAP rising to the challenges.
Author: Pierre Gorel1
1 SNOLAB
Corresponding Author: [email protected]
DEAP-3600 is a single-phase liquid argon WIMP detector, operating at SNOLAB (Sudbury, Ontario) since 2016. With the 2km rock overburden, the facility boasts one of lowest muon flux in the word. DEAP-3600 was built with the goal of being background-free in the region of interest for three years. The design choices made to meet this requirement meant that no calibration source couldbe deployed inside the argon volume, leading to an interesting energy calibration challenge. In this talk, we will show how the DEAP collaboration used the internal 39Ar background and an external 22Na source to calibrate the energy response of the detector in the region of interest. While this method laid satisfactory results for the first WIMP search, an improvement in sensitivity will required a better understanding of the energy response, particularly at low energy. We will also
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present here the new calibrations sources DEAP intends to use to refine the energy calibration of the detector.
W1-10 Nuclear Structure III (DNP) | Structure nucléaire III (DPN) / 2821
Investigating shell evolution in neutron-rich Kr isotopes with trans- fer reactions
Authors: David Walter1; Rituparna Kanungo1; Matthias Holl1; IRIS Collaboration2
1 TRIUMF / Saint Mary’s University 2 TRIUMF
Corresponding Author: [email protected]
Neutron-rich nuclei near the N=50 closed shell are of particular interest for their role in the rapid neutron capture process (r-process) of heavy element nucleosynthesis. Nuclear properties such as neutron capture rates and spectroscopic properties are crucial inputs to constrain theoretical mod- els and improve their predictive power to properties of exotic, neutron-rich isotopes where little to no experimental information is known. In the region of N=50-60, a different trend of shell evolu- tion is hinted for the Kr isotopes compared to the neighboring Zr and Sr isotopic chains, however there is limited information available for neutron-rich Kr isotopes. The systematics of the excited 0+ state along these isotopic chains would provide insight into the neutron orbital occupancies and hence shell evolution in neutron-rich Kr isotopes. To address the unknown excited 0+ states in 94Kr and 92Kr, the neutron transfer reactions 93Kr(d,p) and 93Kr(d,t) were performed at the ISAC II facil- ity at TRIUMF using the ISAC Charged Particle Spectroscopy Station (IRIS). Information about the experiment and preliminary results will be presented.
T1-8 Topics in medical physics and biophysics (DPMB) | Sujets en physique médicale et bio- physique (DPMB) / 2822
Monitoring and Optimizing Beer Flavour and Quality Using Ra- man Spectroscopy
Authors: Benjamin Cudmore1; Derek Lawther1; Pragya Chowdhury1; Ryan Legault2; William Whelan1
1 University of Prince Edward Island 2 University of New Brunswick
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected]
There is a particular interest to improve the characterization of the bitterness of beer whichisderived primarily from the addition of the annual flowers (cones) of the perennial climbing vine Humulus lupulus, better known as common hops. The hops cones contain important acids called humulones. During the brewing process, the humulones are thermally isomerized into isohumulones which are highly bitter and contribute to the beer’s flavour profile. Despite significant contributions tobeer flavour and quality, the degree of humulone isomerization is typically not monitored in microbrew- eries, due in part to the lack of easy-to-use, cost-effective and on-site testing methods. Raman spec- troscopy is being explored to 1) measure humulones in hops plants and processed hops pellets and 2) measure isohumulones and the resulting sensory bitterness in beer. Raman spectroscopy probes molecular vibrations and, as such, is an attractive analytical tool for the identification and quantifi- cation of specific molecules of interest in plants/food. A portable, hand-held Raman spectroscopy system (NanoRam, B&W Tek) with excitation at 785 nm is being tested. Preliminary data demon- strates the capability to measure humulones in the glands on the underside of hops leaves (Chinook variety) and in hops pellets with varying humulone concentrations. Raman spectra of wort samples,
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provided by a local microbrewery, exhibit a strong fluorescence background. However, by adding methanol to the wort, at increasing concentrations, Raman peaks associated with methanol’s C-O and O-H bonds shift to lower wavenumbers, indicating a change in the vibrational/rotational fre- quency modes of these bonds. It may therefore be possible to use these types of peak shifts to monitor the hops thermalization processes. The overall goal of this research is to develop a field- ready, cost-effective Raman spectroscopy technique for monitoring and optimizing beer flavour and quality.
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2823
Photoconductivity of SnIP Semiconducting Inorganic Double He- lices
Author: David Purschke1
Co-authors: Ebru Uzer 2; Claudia Ott 2; Markus Pielmeier 2; Naaman Amer 1; Tom Nilges 2; Frank Hegmann 1
1 University of Alberta 2 Technical University of Munich
Corresponding Authors: [email protected], [email protected]
Recently synthesized, tin iodide phosphorus (SnIP) is the first of a new class of materials with carbon- less double-helix structure [1]. Unlike DNA, which consists of two equal-radius helices, the SnIP double helix consists of an outer SnI chain with 0.98 nm diameter wrapping around an inner P chain. Bulk SnIP consists of bundles of needles weakly bound through Van-Der Waals forces to form long needles. SnIP is predicted to be a semiconductor, which is validated by diffuse reflectivity and photoluminescence measurements that indicate a band gap of 1.8 eV [1]. Interestingly, the weak inter-helix bonding means that the SnIP needles have favorable mechan- ical properties, and an individual SnIP needle can be bent to 90 degrees, which, combined with the predicted high mobility (greater than 2000 cm2 V-1 s-1 [2]), suggests possible applications in flexible electronics. Additionally, the quasi-1D crystal structure suggests an effective reduction of dimensionality, which should result in highly anisotropic transport properties where photoexcited electrons are confined to move along the axis of the helices. Here we present recent results probing bulk and delaminated SnIP needles with time-domain tera- hertz spectroscopy (THz-TDS) and time-resolved THz spectroscopy (TRTS) [3]. TDS measurements reveal the presence of a strong vibrational mode in the middle of the THz spectrum. Comparison with quantum chemical calculations shows that motion in this frequency range can be assigned to vibrations of the outer SnI helix. TRTS measurements, using both sub gap and above gap excitation, reveal recombination dynamics that follow a stretched exponential and power law decay respec- tively, with lifetimes of tens of picoseconds. An increasing lifetime with excitation fluence suggests that these dynamics are governed by saturation of trap states at high injection levels. Finally, we will discuss progress towards synthesis of aligned SnIP samples suitable for exploration of the anisotropic photoconductivity. [1] D. Pfister et al., “Inorganic Double Helices in Semiconducting SnIP,” Adv. Mat. 28, 9783(2016). [2] X. Li et al., “Landscape of DNA-like inorganic metal free double helical semiconductors and potential applications in photocatalytic water splitting,” J. Mater. Chem. A 5, 8484 (2017). [3] P. U. Jepsen et al.., “Terahertz spectroscopy and imaging - Modern techniques and applications,” Laser Photonics Rev. 5, 124 (2011).
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2824
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47 - A Slow Optical Centrifuge
Authors: Ian MacPhail-Bartley1; Walter Wasserman2
Co-authors: Jordan Fordyce 1; Valery Milner 1
1 UBC 2 University of British Columbia
Corresponding Author: [email protected]
An optical centrifuge is a tool for controlling coherent molecular rotation with an intense laser field. It is a linearly polarized pulse which starts by rotating slowly and accelerates up to ∼10 THz over ∼100 ps. Whether a molecule will follow it is determined by comparing the molecule’s moment of in- ertia to the anisotropic polarizability of the molecule. Several light diatomic and triatomic molecules have been spun (O2,N2, CS2, OCS, CO, CO2) and more recently the larger chiral molecule propylene oxide (CH3CHCH2O) has been shown to orient when spun with the centrifuge. These larger and more complex molecules respond to the twisting polarization vector more slowly so require either a slower acceleration or a stronger field. The latter is limited by multi-photon ionization, sosimply amplifying the centrifuge pulse is not an option. By increasing the duration of the centrifuge while reducing the maximum rotational frequency, the adiabatic trapping probability is improved. This allows a high degree of rotational excitation in circumstances which were previously unattainable such as for heavier more complex molecules or those with a lower anisotropic polarizability. This will be applied to the study of laser-induced chiral molecule orientation, and molecular superro- tors in superfluid helium nanodroplets. We present characterization methods for this “slow” optical centrifuge which take advantage of the uniquely shaped pulses.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2825
4 - Plasmonic All-Optical Switching by Metamaterial-Dielectric Mach-Zehnder Interferometer
Authors: Fariba Lotfi1; Nafiseh Sang-Nourpour2; Reza Kheradmand3
1 Photonics group, Research Institute for Applied Physics and Astronomy, University of Tabriz, Iran 2 Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada 3 Photonics group, Research Institute for Applied Physics and Astronomy, University of Tabriz, Iran
Corresponding Authors: [email protected], [email protected], [email protected]
We present a nanoscale low-power all-optical switching approach based on surface-plasmon polari- tons (SPPs) by employing the concept behind Mach-Zehnder interferometer (MZI). The capabilities of SPPs to confine energy of electromagnetic waves in the subwavelength scale provide the possibil- ity to design miniaturized all-optical switches. We employ nanoscale plasmonic waveguides in MZI and add a pump to the structure to provide on/off states in the all-optical switch. The waveguide cladding is made of lossy media including metamaterials, with positive and negative electromagnetic susceptibilities, and metals and the core consists of dielectrics and nonlinear media. By turning the pump on or off, the pump energy affects the Kerr nonlinear material in the waveguide coreatoneof the interferometer branches that provides constructive or destructive interferences between propa- gating SPPs in the up and down branches of the interferometer. Employing metamaterials, instead of commonly used metals, in the switch structure facilitates the propagation of both transverse electric and transverse magnetic SPPs along the waveguides, which enables on/off states for both transverse electric and transverse magnetic modes in the switch. Our all-optical switch design enables multi- frequency switching with low-intensity pump field. Ascertaining the capabilities of multi-frequency plasmonic all-optical switches facilities their applications in miniaturized photonic circuits.
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M2-4 Emerging investigators in bioimaging and medical applications of optics (DPMB/DAMOPC) | Chercheurs émergeants en bioimagerie et applications médicales de l’optique (DPMB/DPAMPC) / 2826
The optical properties of aging and diseased tissue interfaces: what are your gums and bones telling you?
Author: Ozzy Mermut1 Co-authors: Rohith Kaiyum 1; Kevin Borsos 1; Hassan Moghadam 2
1 York University 2 The Ottawa Hospital, McGill University
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Detection of inflammation and classification of pathological lesions, for example in the oraldis- eases and cancer applications, has typically be restricted to expensive imaging modalities such as X-rays which suffer from poor spatial resolution and lack functional information for early diagnos- tics. Other traditional imaging such as computed tomography (CT) cannot be used during treat- ment or surgical procedures and are difficult techniques to access sensitive areas of a patients’ oral cavity. Moreover, CT and X-ray imaging are not sufficiently sensitive and specific to sense early stage biomarkers of inflammatory response in aging and pre-diseased tissue. Here we present the development of a non-invasive optical coherence tomography (OCT) technique to examine the struc- tural integrity and connectivity at the interfaces of soft and hard tissue surfaces as a pre-diagnostic biomarker of oral disease. We evaluate the efficacy of this method for lesions discrimination from healthy tissue based on measurement of optical property variances, namely scattering and refractive index, in periodontal tissue multilayer interfaces. Specifically, we use stable and well-controlled opti- cal phantoms to examine the OCT-derived properties across 1-2mm tissue-bone models to determine the limit of detection for periodontal pocket depth. We aim to compare these model systems with in vivo characterizations of bone structures through small layers of epithelial cells of the gum. We further introduce a multi-modal approach for in vivo time-resolved near infrared-OCT (NIR-OCT) which enables a novel in situ probe for structural-functional optical assessment of inflamed tissues through examination at these soft-hard tissue interfaces, such as through observation of variations of oxy-/deoxy- hemoglobin absorption local gradients of pH. We will also demonstrate the design and integration of biocompatible optical clearing agents for enhanced functional contrast. To compli- ment and overlay the high resolution optical scattering map of the gum-hard tissue interface, weaim to co-register it with NIR functional contrast associated with the local inflamed microenvironment. Finally, we discuss the broader relevance of this time-resolved NIRS diffuse reflectance method as a means for optically-stable biochemical contrast in other inflammatory environments and applica- tions. Our technique presents new opportunities for exploring combined structure-function optical classification of soft-hard interfaces in connective tissues as biomarkers for understanding agingand early detection of degenerative diseases.
M2-9 Magnetism and heavy fermions II (DCMMP) | Magnétisme et fermions lourds II DPMCM) / 2827
Discovery and Characterization of New Frustrated Magnetic Sys- tems
Authors: Graeme Luke1; Yipeng Cai1; James Beare1; Georgia Thomas1; Adam Aczel2; Casey Marjerisson1
1 McMaster University 2 Oak Ridge National Laboratory
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Magnetic frustration occurs when a material’s lattice geometry prevents it from finding the classical ground state which minimizes pairwise magnetic interaction energies. In such situations, novel
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ground states with exotic properties can emerge: examples include classical and quantum spin ice and classical and quantum spin liquids. Many different states and excitations have been predicted theoretically, but the study of their physical properties requires real physical realizations of these models. We have been searching for new geometrically frustrated magnetic materials to broaden the range of materials that can be studied to identify new ground states and novel excitations. I will describe our work to synthesis a stacked triangular system ErMgGaO4 and the related garnet Er3Ga5O12, which we have characterized with magnetic susceptibility, specific heat, muon spin relaxation and neutron scattering. We find that the spins in remain dynamic down to our lowest temperatures (50mK), making this system a candidate spin liquid. I will also describe our ongoing work on new materials whose lattice is derived from the highly frustrated pyrochlore and kagome lattices where we have successfully synthesized single crystal and polycrystalline specimens of several new compounds.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2828
73 - Search for SUSY with missing transverse momentum and multiple b-jets
Author: Meisam Ghasemi Bostanabad1
1 University of Victoria (CA)
Corresponding Author: [email protected]
Strong multi-b analysis: A search for supersymmetry involving the pair production of gluinos decaying via third generation 0 squarks into lightest neutralino (χ˜1) is performed. The final state contains large missing transverse momentum and several energetic jets, at least three of which must be identified as b-quarks. The −1 analysis uses the dataset√ of proton-proton collisions with an integrated luminosity of 79.8 fb , recorded with ATLAS at s = 13 TeV. No excess is found above the predicted background. For 0 χ˜1 masses below approximately 800 GeV, gluino masses of less than 2.2 TeV are excluded at 95% confidence level. Electroweak multi-b analysis: This analysis searches for supersymmetric partners of Higgs boson (higgsinos H˜ ) in gauge-mediated scenarios. Each higgsino is assumed to decay to a Higgs boson and gravitino. Different Higgs reconstruction methods have√ been tested to provide higher signal gain. LHC pp collision data at a center-of-mass energy s = 13 TeV, with an integrated luminosity of 36.1 fb−1 collected with ATLAS detector in 2015 and 2016 is used as an input. Limits on the cross-section are set as a function of the mass of the H˜ in simplified model assuming higgsinos decaying to a Higgs boson anda gravitino.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2829
59 - Carbon disulfide superrotors in helium nanodroplets
Author: Jordan Fordyce1
Co-authors: Ian MacPhail-Bartley ; Walter Wasserman ; Frank Stienkemeier 2; Valery Milner 3
1 Jordan
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2 University of Freiburg 3 UBC
Corresponding Author: [email protected]
The behaviour of fast rotating molecules immersed in superfluid helium is studied. More specifically, the system of interest is carbon disulfide “superrotors” inside helium nanodroplets. Droplets ideally capture a single carbon disulfide molecule and are then exposed to two laser beams. The first beam,a laser pulse whose linear polarization undergoes accelerated rotation around the direction of the laser beam, called an “optical centrifuge“, excites them to the extreme rotational states. The second beam, a femtosecond “probe“, ionizes the molecules. The recorded velocity map ion image is analyzed to determine the rotational state, or degree of confinement to the rotational plane, of the molecules. Confinement to the rotational plane is characterized by < cos2Ѳ2D > which is the average valueofthe cosine of the angle between the probe polarization and the rotational ion velocity vector projected onto the detector screen. By observing how < cos2Ѳ2D > evolves in time after the centrifuge pulse is gone, inferences about the coupling strength of helium to the superrotor can be made. If helium couples strongly to the rotor then < cos2Ѳ2D > is expected to be low and decay quickly. If coupling is weak then < cos2Ѳ2D > is high and lasts for a long time. This is measured for carbon disulfide doped droplets and the evolution of < cos2Ѳ2D > is presented, which is an exciting first step in understanding how the rotation dynamics of a molecule can probe the superfluid behaviour of the nanodroplets.
R2-3 Quantum Optics and Ion traps (DAMOPC) | Optique quantique et pièges d’ions (DPAMPC) / 2830
Quantum simulation of 2D and 3D spin systems in a linear chain of trapped ions
Author: Rajibul Islam1
1 University of Waterloo
Trapped ions are a leading hardware platform for quantum information processing, in particular quantum simulation. Qubits or (pseudo-)spin states encoded in the internal electronic structure of ions can be precisely controlled, and quantum coherence for individual qubits can last for several minutes. Phonon-mediated programmable long range inter-spin interactions can be engineered by shining the ions with suitable laser beams, enabling the simulation of a many types of spin Hamil- tonians such as long range quantum Ising and XY models. In this talk, I will give an overview of trapped ions as a versatile platform for quantum simulation. The interaction graph between spins can be engineered to study spin Hamiltonians on dynamically re-programmable lattice geometries, enabling the investigation of a wide range of quantum many-body physics problems in 1D, 2D and 3D, such as geometrically frustrated spin systems, quantum transport, and dynamical phase transi- tions in a linear chain of ions.
T2-4 Indirect and collider searches for dark matter (PPD) | Recherches indirectes et par colli- sionneurs pour la matière sombre (PPD) / 2831
Overview of Dark Matter Searches by the ATLAS Experiment
Author: Christopher Ryan Anelli1
1 University of Victoria (CA)
Corresponding Author: [email protected]
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One of the main focuses of the ATLAS experiment is the search for dark matter (DM) production in proton-proton collisions at the Large Hadron Collider (LHC). These searches are commonly in- terpreted in terms of simplified models with a spin-0 or spin-1 mediator particle propagating inter- actions between the visible and dark sectors. Simplified models lead to familiar Mono-X signatures where the presence of non-interacting DM can be inferred as missing transverse momentum caused by DM particles recoiling against a visible particle, X, (i.e. a jet, a photon, or a W, Z or Higgs bo- son). Since the mediators couple to SM particles, they can also be directly searched for though their decays to jets, top-quark pairs, and potentially even leptons. Simplified models describe dark- matter production kinematics with a minimal number of free parameters, but they do not represent complete theories. Recent theoretical efforts have focused on producing complete, renormalizable models of DM. In particular models involving extended Higgs sectors with an additional vector or pseudo-scalar mediator. These models offer rich phenomenologies and new experimental signatures. ATLAS has recently released summary plots gathering the results of more than 20 experimental DM searches. As well as first results utilizing the full 139fb−1 of 13 TeV proton-proton collision collected during Run 2 (2015-2018). ATLAS limits are compared to those set by direct detection experiments, and relic densities for the different DM models are calculated.
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2832
Characterization of the Si:Se+ spin-photon interface
Author: Adam DeAbreu1
Co-authors: Camille Bowness 1; Rohan Abraham 1; Alzbeta Medvedova 1; Kevin Morse 1; Helge Riemann 2; Nikolay Abrosimov 2; Peter Becker 3; Hans-Joachim Pohl 4; Michael Thewalt 1; Simmons Stephanie 1
1 Department of Physics, Simon Fraser University 2 Leibniz-Institut für Kristallzüchtung 3 Physikalisch-Technische Bundesanstalt Braunschweig 4 VITCON Projectconsult GmbH
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Ionized chalcogen donors in silicon, such as S+, Se+, and Te+, offer excellent spin qubit properties on par with the commonly studied group V hydrogenic “shallow” donors such as phosphorus. These deep chalcogen donors have the additional advantage of spin-selective, mid-infrared optical access to their lowest excited valley-orbit states. By coupling this optical transition to silicon photonic cav- ities this provides a natural means of connecting qubits within a cavity-QED architecture. Here we characterize key features of this optical transition in Si:Se+, including the transition dipole moment, radiative efficiency, phonon sideband, and orbital excited state lifetime. These results informthe viability of Si:Se+ as a spin-photon interface within a silicon photonics quantum platform.
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2833
Remarkable linewidth improvements for well-known radiation damage centres in highly enriched 28Si
Authors: Camille Chartrand1; Laurent Bergeron1; Kevin Morse1; Helge Riemann2; Nikolay Abrosimov2; Peter Becker3; Hans-Joachim Pohl4; Stephanie Simmons1; Michael Thewalt1
1 Simon Fraser University 2 Leibniz-Institut für Kristallzüchtung
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3 Physikalisch-Technische Bundestanstalt Braunschweig 4 4VITCON Projectconsult GmbH
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], nikolay.abrosimov@ikz- berlin.de, [email protected], [email protected], [email protected], [email protected]
A multitude of radiation damage centers in Si with highly reproducible optical emission and absorp- tion lines have been studied exhaustively using a wide variety of techniques over the past 50+ years. Some of these centers produce very bright luminescence, and have recently received renewed in- terest as possible light emitters, and single photon sources, compatible with an integrated silicon photonic technology. Previous high resolution studies of these centers in natural Si have shown reproducible limiting linewidths of typically no better than 0.04 meV, and it has become widely as- sumed that these relatively narrow linewidths represent some kind of fundamental limit for these centers. We show [1] that these linewidths in fact result from inhomogeneous broadening due to the mixed isotopes present in natural silicon, and that the linewidths observed for ensembles of these defects in highly isotopically enriched 28Si can be over two orders of magnitude narrower. We report results for the W line, which emits at 1218 nm, the G line which emits at 1279 nm, and the C line which emits at 1570 nm, all near important telecommunication bands. Not only do these emission lines become dramatically narrower in 28Si, in some cases less than the 0.25 μeV limiting resolution of our spectrometer, but for one of these centers fine structure is revealed which is hidden in ensem- ble spectra from natural Si. These results have direct implications for the spectral widths andfine structure to be expected from individual emitters, even in natural Si. [1] C. Chartrand, L. Bergeron, K. J. Morse, H. Riemann, N. V. Abrosimov, P. Becker, H.-J. Pohl, S. Simmons, and M. L. W. Thewalt, Highly enriched 28Si reveals remarkable optical linewidths and fine structure for well-known damage centers. Physical Review B 98, 195201 (2018).
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2834
Universality of Spreading Processes with Spontaneous Activity
Authors: Daniel Korchinski1; Javier Orlandi1; Seung-Woo Son2; Joern Davidsen3
1 The University of Calgary 2 Hanyang University 3 University of Calgary
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Spreading processes on networks are ubiquitous, including neuronal avalanches, human and com- puter viruses, and information spreading on social networks. Spreading processes exemplify a nonequilibrium phase transition into an absorbing state; the transition to the absorbing state will certainly occur when the mean branching ratio falls below one. These processes are typically stud- ied assuming some number of initial seeds from which the activity spreads and fall into the uni- versality class of directed percolation. This approach is best justified for processes in which the initiation of activity occurs on timescales much greater than the timescale of spreading. However, this separation of timescales is not always justified. For example, transmissible zoonotic diseases spread amongst humans concurrent with new infections from animals. In this talk, we introduce the spreading process with spontaneous activity. Spontaneous activity destroys the absorbing state and therefore changes the underlying universality class of the spreading process. We argue, from extensive numerical simulation and analytical arguments that the universality class changes from directed percolation to that of undirected percolation. In numerical simulations, we identify critical exponents of directed percolation on small scales, but asymptotic behaviour governed by undirected percolation exponents. Using a tree-like mean-field approach, we identify a critical line along which
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universal scaling occurs. Our mean-field predictions are borne out reasonably well for power-law and small-world graphs. The inclusion of spontaneous activity in the spreading process bridges the universality classes of undirected and directed percolation. This enriched spreading process has potential application in epidemiology and in neuroscience.
W1-9 Condensed matter systems & related: experiment & theory (DCMMP) | systèmes de matière condensée et expérience et théorie connexes (DPMCM) / 2835
Size bistability in multiferroic nanoparticles
Authors: Marc Allen1; Ian Aupiais2; Maximilien Cazayous2; Rogério de Sousa1
1 University of Victoria 2 Université Paris Diderot
Corresponding Authors: [email protected], [email protected]
Most multiferroic materials with coexisting ferroelectric and magnetic order exhibit cycloidal an- tiferromagnetism with wavelength much larger than lattice spacing. The prototypical example is bismuth ferrite (BiFeO3 or BFO), a room-temperature multiferroic considered for a number of tech- nological applications, including magnetic memories with electric-write capability. While most ap- plications requires small sizes such as nanoparticles, little is known about the state of these materials when their sizes are comparable to the cycloid wavelength. This work describes a theory of cycloid magnetism in nanoparticles. It is argued that magnetic anisotropy close to the surface has a huge impact on the ground state cycloidal wavevector, leading to several observable consequences. For certain sizes the cycloidal wavevector is bistable, an effect that may be exploited in the design of novel memory devices.
T2-9 Fields and Strings I (DTP) | Champs et cordes I (DPT) / 2836
Spacetime from bits and cosmology from black holes
Author: Mark Van Raamsdonk1
1 UBC
Corresponding Author: [email protected]
In this talk, I will discuss two applications of holographic duality for CFTs with boundaries (BCFTs). First, I will discuss how to describe smooth spacetimes via multipart entangled states of many non-interacting BCFT systems. As a second application, I will describe the construction of certain black hole microstates for which the behind-the-horizon geometry can be deduced explicitly. The latter construction may provide a way toembed cosmological physics within AdS/CFT.
T1-9 General Relativity II (DTP) | Relativité générale II (DPT) / 2837
New thermodynamic identities for five-dimensional black holes
Author: Hari Kunduri1
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1 Department of Mathematics and Statistics, Memorial University of Newfoundland
Corresponding Author: [email protected]
Stationary black hole solutions of classical general relativity satisfy certain identities relating their mass, angular momenta, and charge which are in close analogy with familiar thermodynamic laws. In this talk I will describe new identities for the physical variables of five-dimensional, asymptotically flat, stationary vacuum black holes. Unlike the well known Smarr relation, these identities depend on the topology of the black hole spacetime. The proof employs the harmonic map (sigma model) formulation of the vacuum Einstein equations for solutions in the presence of symmetries.
W1-3 Topics in Medical Physics (DPMB) | Sujets de physique médicale (DPMB) / 2838
Intracellular Retention and Redistribution of Gold Nanoparticles with Docetaxel
Authors: Aaron Bannister1; Devika Chithrani1
Co-authors: Kyle Bromma 1; Leah Cicon 1
1 University of Victoria
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Docetaxel (DTX) is an anticancer drug used in combination with radiotherapy to treat many cancers. Currently, Gold nanoparticles (GNPs) are being tested as novel radiosensitizers in radiotherapy. Ad- dition of GNPs into this current protocol is expected to produce further therapeutic benefits. Our goal was to elucidate the behavior of GNPs in the presence of DTX since it can disturb the micro- tubule network affecting the vesicle transport of GNPs within cells. We tested our hypothesis using clinically feasible concentrations of DTX (50 nM) and GNPs (0.2 nM). Concurrent treatment of DTX and GNPs resulted in an over 80% increase in the retention of GNPs and forced them closer to the most important target, the nucleus. DTX appears to allow endocytosis while blocking exocytosis through restricting transport of vesicles to the cell surface, leading to an aggregation of GNPs sur- rounding the nucleus. This would cause more DNA damage from the extra short-range secondary electrons produced by GNPs during radiotherapy. DTX also prevents redistribution of GNPs into daughter cells by blocking cells in the G2/M phase of the cell cycle, already the most radiosensitive phase. The ability to trap GNPs at clinically feasible doses would lead to meaningful nanotechnology- based platforms in future combined therapy.
T3-9 Cosmology (DTP) | Cosmologie (DPT) / 2839
TO BE REPLACED - A new semiclassical picture of vacuum de- cay
Author: Matthew Johnson1
1 York University/Perimeter Institute
Corresponding Author: [email protected]
In this talk I will introduce a new real-time description of vacuum decay in quantum field theories. Vacuum decay via bubble formation is simulated by generating realizations of vacuum fluctuations and evolving lattice simulations with the classical equations of motion. The decay rate obtained from an ensemble of simulations is in excellent agreement with existing semi-classical techniques. I will discuss possible future applications, including bubble correlation functions, decay of non-vacuum states, and possible laboratory experiments that could be used as quantum simulators of vacuum decay.
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W2-4 Fields and Strings II (DTP) | Champs et cordes II (DPT) / 2840
Entanglement and the Infrared
Author: Gordon Semenoff1
1 University of British Columbia
Corresponding Author: [email protected]
There are two known apparently massless fields in nature, the photon and the graviton. Interestingly, their massless nature in each case leads to similar infrared catastrophes for quantum electrodynam- ics and perturbative quantum gravity. In this talk, I will review some quantum information theoretic issues stemming from the copious production of soft photons and soft gravitons in elementary par- ticle interactions.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2841
WITHDRAWN- Fiducial Differential Cross Section Measurements in the HZZ4l Channel with the ATLAS Detector
Author: Laurelle Maria Veloce1
1 University of Toronto (CA)
Corresponding Author: [email protected]
Detailed tests of the Standard Model nature of the Higgs boson are a key component of the physics program at the ATLAS experiment. An overview of inclusive and fiducial differential cross section measurements in the HZZ4l channel will be presented. Higgs boson candidate events are selected by identifying two pairs of same-flavour oppositely-charged leptons (electrons or muons). Total cross sections are measured both inclusively and separately in each final state. Differential cross sections are measured inclusively for observables which are sensitive to the production and decay of the Higgs boson, including the transverse momentum of the four-lepton system and the multiplicity of the associated jets. Measurements are performed in a fiducial phase space and are corrected for detector effects. Past results and future prospects of this measurement will be discussed.
DAPI Poster Session & Student Poster Competition Finals (8) | Session d’affiches DPIA et finales du concours d’affiches étudiantes (8) / 2842
5 - Can Operating Conditions affect CANDU® Pressure Tube Re- sistivity?
Authors: Perryn Bennett1; Matt Topping1; Ross Underhill2; Jordan Morelli1; Mark Daymond1; Thomas Krause2
1 Queen’s University 2 Royal Military College
Corresponding Author: [email protected]
For eddy current based inspections of CANDU® reactor fuel channels, material electrical resistivity is an important parameter. For pressure tube (PT) to calandria tube (CT) gap measurements, mate- rial resistivity values are required to ensure accurate measurement of the gap. The resistivity used
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during inspections are assumed to be the same as that of calibration PTs, which are non-heat treated, non-irradiated and are assumed to reflect that of in-reactor conditions. In contrast, other important parameters in gap measurement are affected by in-reactor conditions, such as PT wall thickness and PT diameter, and are compensated for using in-reactor measurements. To test the hypothesis of whether sustained elevated temperatures, similar to in-reactor conditions, could change a material’s resistivity, this study examined the effect of heat treatment on the resistivity of Zr2.5%Nb. Under anaerobic furnace conditions, sectioned PT samples were held for varying periods of time at 400 ℃ and 450 ℃, to partially decompose beta-Zr and produce varying fractions of omega-Zr. Tempera- tures of 400 ℃ and 450 ℃ were chosen to accelerate the phase transformations that take place over a long period of time under reactor operating conditions, where temperatures are between 250 ℃ and 310 ℃. Using the four-point resistivity measurement technique, the resistivity of the heat-treated PT samples was measured and changes in resistivity with time at temperature were recorded. The mag- nitude of the resistivity was observed to decrease by up to 10% with time in the furnace. Reduction of resistivity with heat treatment was associated with changes in the microstructure. Examination by transmission electron microscopy (TEM) showed an increase in the volume fraction of hcp omega- phase, and associated bridging between higher conductivity alpha-Zr grains, which consequently would result in an overall decrease of resistivity. These results have implications for the estimated uncertainty of PT to CT gap measurement, where temperature variation arises along the channel and between 6 and 12 o’clock at a given axial position.
W2-2 Quantum Information (DAMOPC/DTP) | Information quantique (DPAMPC/DPT) / 2843
Quantum optics approaches for quantum networks and other ap- plications
Author: Christoph Simon1
1 University of Calgary
Quantum networks promise many exciting applications from secure communication over distributed sensing to distributed quantum computation. I will describe several efforts related to designing the hardware architecture for such quantum networks. One approach towards a global quantum net- work combines quantum communication satellites with quantum repeaters . An important capabil- ity in this context is the ability to detect photonic qubits non-destructively, which may be possible in solids using single rare-earth ions or ensembles of rare-earth ions . Single rare-earth ions are also promising for the implementation of quantum repeaters . An attractive approach towards distributed quantum computing is to connect superconducting quantum processors via optical channels . This requires the transduction of photons from the microwave to the optical domain, which may also be possible using rare-earth ion ensembles in solids . In the long term it would be highly desirable to realize quantum networks whose components can operate at ambient temperature. This may be pos- sible using plasmonics or spin-optomechanics approaches. Finally it is interesting to ask whether there could be quantum networks in the brain . Besides quantum networks, I will also briefly de- scribe efforts towards bringing quantum effects to the macroscopic level , as well as anapproach towards super-resolution imaging using heterodyne detection. K. Boone et al., Entanglement over global distances via quantum repeaters with satellite links, Phys. Rev. A 91, 052325 (2015); C. Simon, Towards a global quantum network, Nat. Photon. 11, 678 (2017). C. O’Brien, T. Zhong, A. Faraon and C. Simon, Non-destructive photon detection using a single rare- earth ion coupled to a photonic cavity, Phys. Rev. A 94, 043807 (2016). N. Sinclair et al., Cross-phase modulation of a probe stored in a waveguide for non-destructive detec- tion of photonic qubits, Nat. Comm. 7, 13454 (2016); S. Goswami, K. Heshami and C. Simon, Theory of cavity-enhanced non-destructive detection of photonic qubits in a solid-state atomic ensemble, Phys. Rev. A 98, 043842 (2018). F. Kimiaee Asadi et al., Quantum Repeaters with individual rare-earth ions at telecommunication wavelengths, Quantum 2, 93 (2018). S. Kumar, N. Lauk and C. Simon, Towards long-distance quantum networks with superconducting processors and optical links, arXiv:1812.08634 S. Welinski et al., Electron Spin Coherences in Rare-Earth Optically Excited States for Microwave to Optical Quantum Transducers, arXiv:1802.03354
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S. Wein, N. Lauk, R. Ghobadi and C. Simon, Towards room temperature indistinguishable single- photon sources using ultra-small mode volume cavities and solid-state emitters, Phys. Rev. B 97, 205418 (2018). R. Ghobadi et al., Towards a Room-Temperature Spin-Photon Interface based on Nitrogen-Vacancy Centers and Optomechanics, arXiv:1711.02027. S. Kumar et al., Possible existence of optical communication channels in the brain, Sci. Rep. 6, 36508 (2016). P. Zarkeshian et al., Entanglement between more than two hundred macroscopic atomic ensembles in a solid, Nat. Comm. 8, 906 (2017); D.V. Sychev et al., Entanglement of macroscopically distinct states of light, arXiv:1811.01041. F. Yang et al., Far-field linear optical superresolution via heterodyne detection in a higher-order local oscillator mode, Optica 3, 1148 (2016); F. Yang et al., Fisher information for far-field linear optical superresolution via homodyne or heterodyne detection in a higher-order local oscillator mode, Phys. Rev. A 96, 063829 (2017).
W1-3 Topics in Medical Physics (DPMB) | Sujets de physique médicale (DPMB) / 2844
Optimization of Dental Cone Beam Computed Tomography for Planning Dental Implant Treatments
Author: Nancy L. Ford1
1 The University of British Columbia
Corresponding Author: [email protected]
Dental cone beam computed tomography (CBCT) has been a transformative technology for the den- tal profession, providing 3D imaging for individual teeth, the entire jaw or even the entire cranio- facial complex. Advantages of dental CBCT machines include upright scanning, which provides a more natural mandible position, the convenience of producing 3D images in the dental office, and a reduced radiation dose compared with head CT scans, albeit with reduced image quality. One of the most frequent uses of dental CBCT is for planning dental implants. Images are obtained to ensure that the underlying bone is thick enough to support the metal implant, and to identify if the bone is thick enough for the implant screw to fit without impinging upon the inferior alveolar nerve along the mandible or perforating into the maxillary sinus. Virtual implants can be inserted into the images to aide in identifying the correct location and angulation during surgery. In addition, surgical guides can be printed from the image information to assist the clinician with implant placement during surgery. To optimize the CBCT acquisition parameters for implant planning, we performed a number of ob- jective image quality measurements and dosimetry using phantoms. We also performed an observer study focused on the clinical imaging criteria for implant planning. Together, these objective and sub- jective metrics provide optimized image acquisition settings that ensure adequate image quality for the minimum radiation dose to the patient. To further characterize the bone, we are developing post- reconstruction techniques to rescale the images into Hounsfield units for better comparison with CT. We are also characterizing the impact of metal artifacts due to pre-existing implants or amalgams on the ability to measure bone quality and thickness for implant treatment planning.
M2-10 Soft condensed matter II (DCMMP) | Matière condensée molle II (DPMCM) / 2845
Polymer dynamics in confined flows
Author: Colin Denniston1
1 University of Western Ontario
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Corresponding Author: [email protected]
It is well know that even in equilibrium the dynamics of a polymer in solution are affected by hy- drodynamics and follow Zimm, rather than Rouse, dynamic scaling. However, due to the difficulties in correctly simulating a polymer in a real solvent, most simulations of polymers in solution have used Langevin dynamics which do not include hydrodynamics. My group has created a package for the open-source molecular dynamics package LAMMPS for simulations of particles in a fluid that includes full hydrodynamics. I will describe some of our studies of polymers in confined en- vironments experiencing different flow fields. In particular, we will focus on polymers inchannels with constricting and diverging flows and polymer margination in shear flow near a surface. The inclusion of full hydrodynamics is found to have a profound impact on the non-equilibrium behavior observed in these systems.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2846
60 - Fiber-based nanoprobe for the detection of chemicals
Authors: Navneet Kaur1; Joshua Trevisanutto2; Gautam Das2
1 Department of Physics, Lakehead University 2 Lakehead University
Corresponding Authors: [email protected], [email protected], [email protected]
Optical tweezing is a well-known phenomenon for trapping or manipulating dielectric and metallic nanoparticles. The application of metallic nanoparticles in sensing has attracted much attention due to their unique optical and chemical properties. We manufactured a unique plasmonic structure on the surface of a nanoprobe. The nanoprobe was a tapered fiber, which was developed using ady- namic etching method where Hydrofluoric (HF) acid was used to etch a Multi-mode fiber (MMF).A laser was coupled to the un-tapered end of the nanoprobe, and along the tapered length the field was allowed to interact with the environment to trap the metallic nanoparticles via optical tweezing. To explain the formation of the nanostructure on the tapered fiber, we will present results of theoretical and experimental investigations. The theoretical results will include the variation of the mode field distribution as the diameter of the tapered fiber section changes. The theoretical results assisted in estimating the tip diameter to trap a single gold nanorod. We will present the Raman Spectra of chemicals (e.g. Rhodamine 6G) obtained using the nanoprobe. We will investigate the role of the plasmonic structure to enhance the Raman Spectrum. The authors acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and Canada Foundations for Innovations. Authors also gratefully ac- knowledge the contributions of past graduate and undergraduate students in the Photonics Research group.
W2-3 Molecular Motors (DPMB) | Moteurs moléculaires (DPMB) / 2847
Optical control of fast and processive engineered myosins in vitro and in living cells
Authors: Paul RuijgrokNone; Rajarshi GhoshNone; Muneaki NakamuraNone; Sasha ZemskyNone; Robert ChenNone; Vipul VachharajaniNone; Jan LiphardtNone; Zev BryantNone
Spatiotemporal control of cytoskeletal transport can provide new possibilities for dissecting cellular processes and for constructing complex artificial devices. Optogenetic approaches have been used for both controlled recruitment of motors to cellular cargos [1] and direct modulation of motor speed and direction [2]. Previous designs for light-activated gearshifting [2] were non-processive, and suf- fered from either low velocities or modest degrees of velocity modulation in response to light, limit- ing applications in cell biology and in devices. We have now engineered (i) non-processive myosin
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motors that combine large optical modulation depths with high velocities and (ii) processive myosin motors with optically controllable directionality. We have characterized a series of optimized con- structs using in vitro motility assays of propelled actin filaments, single-molecule tracking of pro- cessive complexes, and live cell imaging of individual motors tagged with fluorescent protein arrays [3]. An extended set of optogenetic motors, together with RNA-protein hybrid motors controlled by oligonucleotide signals [4], will provide a diverse toolkit for programmable control of nanoscale transport and force generation. 1. van Bergeijk, et al. (2015) Nature 518; 2. Nakamura et al. (2014) Nat Nanotechnol 9; 3. Ghosh et al. (2019) Nat Chem Bio 15; 4. Omabegho et al. (2018) Nat Nanotechnol 13
T3-8 Radiation Therapy (DPMB) | Radiothérapie (DPMB) / 2849
Road-map to use of gold nanoparticles in cancer radiotherapy
Author: Devika Chithrani1
1 University of Victoria
Corresponding Author: [email protected]
Radiotherapy is used to treat more than 50% of the cancer patients. Improving the therapeutic ratio, either by reducing the impact of side effects or enhancing the treatment effectiveness locally, isa major goal of current cancer radiotherapy. One of the ways to improve the local radiation dose while minimizing damage to healthy surrounding tissue is to introduction of high Z materials such as gold nanoparticles (GNPs) as radiation dose enhancers. They enhance radiation damage by producing a shower of secondary electrons when exposed to X-ray beams. Radiation dose enhancement prop- erties due to GNPs is dependent on their localization within cells, due to the short range of these electrons. The exact magnitude of the sensitization depends on a number of factors, including GNP size, beam energy, and total dose. However, there has been limited translation of GNP-mediated radiosensitization to a clinical setting. One of the key challenges in this area is the wide range of experimental systems that have been investigated, spanning a range of particle sizes, shapes and preparations. Hence, mechanisms of uptake and radiosensitization have remained difficult to clearly identify. This has resulted in a significant barrier to the identification of optimal GNP formulations which strike a balance among their radiosensitizing properties, their specificity to the tumors, their biocompatibility, and their imageability in vivo. In this talk, I will review the current state of knowl- edge in each of the areas concerning the use of GNPs as radiosensitizers, and outlines the steps which will be required to advance GNP-enhanced radiation therapy from their current preclinical setting to clinical trials in the near future.
T2-7 Nobel Prize Session (DAMOPC) | Session de prix Nobel (DPAMPC) / 2850
Investigation of Multi-frequency Raman Generated Spectra
Author: Donna Strickland1
1 University of Waterloo
Corresponding Author: [email protected]
Since the advent of lasers, many different nonlinear optical techniques have led to shorter, higher- intensity pulses. At Waterloo, we are studying Multi-frequency Raman generation (MRG), which efficiently generates a large number of Raman orders spanning the spectral region from theinfrared to the ultraviolet. The bandwidth of the Raman orders is sufficient to generate single-femtosecond duration pulses. While the pulse duration is longer than what is possible with high order harmonic generation, the conversion efficiency is much higher. While most research in this field is concerned with making as many Raman orders as possible, we noticed that the spectra of the individual Raman
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orders changed dramatically when changing either the dispersion in the nonlinear medium or the laser pump intensity. In this talk, I will discuss the possible physical process causing these changes in the spectra as well as how the changes effect the generation of ultrashort intense pulses.
T4-9 Quantum Theory (DTP) | Théorie quantique (DPT) / 2851
Low-frequency quantum beats in three-level systems
Authors: Christopher DiLoreto1; Chitra Rangan2
1 Northwest Missouri State University 2 University of Windsor
Corresponding Authors: [email protected], [email protected]
Quantum beat spectroscopy is an experimental method that utilizes the interference between en- ergetic transitions in atoms and molecules to detect energy level structures, dipole moments and resonances in complex molecules to a high degree of accuracy. Typically these processes require a high degree of time sensitivity however, in this work we show that specific, off-resonant, experi- mental parameters can be used to create these quantum beats at much lower frequencies while still maintaining significant signal amplitude. This may prove advantageous in improving the quality and ease of these measurements. An analytic calculation, involving a general three-level V system, is used to determine where these off-resonant parameters can be found and a numerical calculation is used to illustrate the decoherence-limited nature of these low-frequencies.
T2-2 Plasmas at Surfaces (DPP) | Plasmas sur des surfaces (DPP) / 2852
Plasma Treatment of Wood Surfaces
Authors: Philip Evans1; Mario Ramos2; Arash Jamali1; Jonthan Haase1; Kenneth Cheng1
1 UBC 2 The Australian National University
Corresponding Author: [email protected]
Plasma is being exploited by industry to increase the wettability and adhesion of coatings to plas- tic automotive components, and to enhance the durability of printing inks on polymers and met- als. These commercial applications of plasma treatments encouraged research on the plasma mod- ification wood. The research mainly focused on the use of plasma to improve the adhesionand performance of glues and coatings on wood; plasma coating of wood to increase its hydrophobic- ity; plasma modification of wood fibres to improve their compatibility with polymers. Ourown research on plasma modification began over 20 years ago with a study of the use of plasma treat- ments to improve the glue bonding of high-density eucalyptus species. We were able to improve the glue bonding of difficult-to-glue eucalyptus species, but improvements appeared to be related to modification of the microstructure of wood rather due to any changes in wetting characteristics of wood. A more recent study also found that modification of the microstructure of wood accounted for improvements in performance of polyurethane coatings on spruce wood. These findings led us to examine the effects of plasma on the microstructure and chemical composition of wood. Weob- served that the microstructure and chemical composition of wood surfaces is profoundly altered by plasma treatments. Plasma causes differential etching of wood’s cellular components, at the surface and also in sub-surface layers. Differential etching of wood’s major chemical components, cellulose, hemicelluloses and lignin also occurs. Cellulose is more susceptible to etching than lignin, and, as a result, the lignin-rich layers of wood cell walls are revealed at surfaces subjected to prolonged plasma etching. Plasma etching of wood can be rapid, depending on wood species and treatment pa- rameters, which has opened up the exciting possibility of using plasma to ‘machine’ wood surfaces and create tailored microstructures with various interesting commercial applications.
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T1-5/T1-7 Strong Correlations in Cold atoms (DAMOPC/DCMMP) | Corrélations fortes dans les atomes froids (DPAMPC/DPMCM) / 2853
Light-cones and quantum caustics in quenched spin chains
Authors: Duncan O’Dell1; Wyatt Kirky1; Jesse Mumford1
1 McMaster University
Corresponding Author: [email protected]
If a single spin in a spin chain is suddenly flipped, the information regarding the disturbance propa- gates outwards at a maximum speed given by the Lieb-Robinson bound. This results in a light-cone- like structure in the space-time dependence of correlation functions which has been observed in experiments with cold atoms and ions. In this talk I will show that these “light cones’’ are examples of quantum caustics. These are discrete matter-wave versions of the caustics known in opticssuch as rainbows and the bright lines on the bottom of swimming pools. Caustics are classified bycatas- trophe theory which endows light cones with certain characteristic features: 1) structural stability; 2) discretized Airy and hyperbolic umbilic functional forms for, respectively, the wave- and correla- tion functions near the cone edges; 3) existence of a lattice of vortex-antivortex pairs inside the light cone. The vortices are sensitive to the quantum phase transition exhibited in spin chain modelsand their rate of production is determined by the dynamical critical exponent.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2854
42 - Adsorption of organic molecules on solid surfaces using sur- factants: A Molecular dynamics study
Authors: Hector Dominguez1; Ana Salazar-Arriaga1; Minerva Valencia-Ortega1; Raul Fuentes-Azcatl1
1 National Autonomous University of Mexico
Corresponding Author: [email protected]
Using simulations of Molecular Dynamics, we investigated the role of surfactant molecules to be used as agents to capture molecules on solid surfaces, either to remove alkane molecules from a graphite surface or to absorb CO2 in a zeolite. Removal of alkanes from graphite plates simula- tions on three different surfactants, Cocamidopropyl betaine (CAPB), N-dodecyl-N.N-dimethyl-3- ammonio-1-propane-sulfonate (SB3-12), Sodium dodecyl sulfate (SDS), and their mixtures at differ- ent compositions were carried out. The study was conducted with different concentrations of decane on the surface and in all cases the alkane molecules were adsorbed on the solid surface in a layer structure, two or three layers, suggested by the density profiles. Surfactants promoted the formation of an additional decane layer, indicating gas separation or removal from the graphite surface. It is shown that mixtures seem to be the best way to remove the alkanes from the surface. Studies of CO2 capture in a zeolite structure were also conducted with and without SDS surfactants on the solid surface. A new force field for CO2 was proposed which reproduced better some ther- modynamic properties. Simulations at different SDS and CO2 concentrations were carried out and it was observed that the best gas adsorption occurs for low CO2 concentration with a few surfac- tants on the surface. Moreover adsorption was mainly conducted from the free ions in the zeolite as indicated by the pair correlation functions. Acknowledgments: DGAPA-Mexico grant IN102017, DGTIC-UNAM grant LANCAD-UNAM-DGTIC-238
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2856
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85 - Modelling emission of acoustic energy during bubble expan- sion in PICO bubble chambers
Author: Tetiana KozynetsNone Co-authors: Scott Fallows 1; Carsten Krauss 1
1 University of Alberta
Corresponding Authors: [email protected], [email protected], [email protected]
The PICO experiment uses bubble chambers filled with superheated C3F8 for spin-dependent WIMP dark matter searches. One of the main sources of background in these detectors is alpha particles from decays of environmental 222Rn, which nucleate bubbles that are visually indistinguishable from WIMP candidate events. It was previously determined that alpha-induced bubbles can be dis- criminated against acoustically, based on the signal from alpha events being consistently larger in magnitude than from nuclear recoil/WIMP-like events. By studying the dynamics of bubbles nu- cleated by these two types of ionizing radiation from the first stages of their growth, we develop a physical model for the acoustic discrimination for the first time. This model is verified bycom- paring the simulated and the experimental distributions of acoustic energies radiated during bubble expansion.
T2-1 Soft Matter AM-2 (DCMMP) | Matière molle AM-2 (DPMCM) / 2857
Enhanced gel formation in binary mixtures of nanocolloids with tunable short-range attraction
Authors: J. L. Harden1; R. L. Leheny1; H. Guo1; M. Bertrand1; T. Shendruk1; S. Ramakrishnan1
1 University of Ottawa
We report a combined experimental, theoretical, and simulation study of the phase behavior and microstructural dynamics of concentrated binary mixtures of spherical nanocolloids with a size ra- tio near two and with a tunable, intrinsic short-range attraction. In the absence of the attraction, the suspensions behave as well mixed, hard-sphere liquids. For sufficiently strong attraction, the suspensions undergo a gel transition. Rheometry measurements show that the fluid-gel boundary of the mixtures does not follow an ideal mixing law, but rather the gel state is stable at weaker in- terparticle attraction in the mixtures than in the corresponding monodisperse suspensions. X-ray photon correlation spectroscopy measurements reveal that, in contrast with depletion-driven gela- tion at larger size ratio, gel formation in the mixtures coincides with dynamic arrest of the smaller colloids while the larger colloids remain mobile. Molecular dynamics simulations of the suspensions similarly observe gel formation driven by a structural arrest of the smaller particles that occurs at weaker strength of attraction than the gel point of the monodisperse suspensions. Characterization of the microstructure n the simulations indicates the arrest results from microphase separation that results from a subtle interplay of entropic and enthalpic effects and that drives the smaller particles to form dense regions. These observations suggest a potential new avenue for tailoring the gel-forming properties of colloidal suspensions.
M1-4 Mathematical Physics (DTP) | Physique mathématique (DPT) / 2858
Qubits as edge state detectors: illustration using the SSH model
Authors: Richard MacKenzie1; Meri Zaimi1; Christian Boudreault2; Hichem Eleuch3; Michael Hilke4
1 U. Montréal
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2 Collège militaire royal de Saint-Jean 3 Abu Dhabi University 4 U. McGill
Corresponding Author: [email protected]
As is well-known, qubits are the fundamental building blocks of quantum computers, and more generally, of quantum information. A major challenge in the development of quantum devices arises because the information content in any quantum state is rather fragile, as no system is completely isolated from its environment; generally, such interactions degrade the quantum state, resulting in a loss of information. Topological states are promising in this regard because they are in ways more robust against noise and decoherence. But creating and detecting edge states can be challenging. We describe a composite system consisting of a two-state system (the qubit) interacting with an SSH chain (a hopping model with alternating hopping parameters). In this model, the dynamics of the qubit changes dramatically depending on whether or not an edge state exists. Thus, the qubit can be used to determine whether or not an edge state exists in this model.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2860
49 - Development of a gold nanoparticle sensor to detect environ- mental DNA of invasive fish species in the Great Lakes
Authors: Meaghen Shiha1; Robert Petro1; Chitra Rangan1
1 University of Windsor
Corresponding Authors: [email protected], [email protected], [email protected]
The goal of my project is to develop a nano-optical sensor platform that can detect invasive fish species in the Great Lakes at the streamside. This is a collaboration between Dr. Rangan (Physics), Dr. Heath (GLIER), Dr. Pitcher (GLIER), and Dr. Mittler (Western University). I am doing prelimi- nary experiments and simulations that can establish proof of principle so that the collaboration can seek external grant funding. I have worked on perfecting the method for creating gold nano-particle islands on glass slides using electroless deposition. With these slide sensor platforms, we will bio- conjugate a recognition site (complementary eDNA) onto the nano-particles, perform a recognition reaction, and detect it using UV-Vis absorption spectroscopy. I will present the preliminary results of this interdisciplinary project.
T3-6 Working as an Industrial, Professional, or Applied Physicist PM-1 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-1 (DPAI) / 2861
Completion of a Prototype Cryogenic Energy Storage and Deep Mine Chilling Co-generation System, Construction of Prototype and Results from Testing.
Author: Daniel Cluff1
1 CanMIND Associates
Corresponding Author: [email protected]
Chilling a deep underground mine is costly and energy intensive. The temperature of the air in- creases as it descends due to the adiabatic lapse rate (called auto-compression in mining), the host
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rock, equipment and processes are additional sources of heat. There is an expectation that battery powered vehicles may allow for less air flow due to reduced airborne particulates, legislation changes pending, that increases the susceptibility to any additional heat. Battery powered vehicles and the charging process both add heat. A reduced air flow reduces the heat needed to raise the temperature to unacceptable levels, which may only require the operation of a few large machines. This paper discusses results from a prototype, a cryogenic co-generation system that stores energy and pro- vides chilling, effectively the heat from the mine is converted to electricity (5 MWe electrical power absorbs 8 MWr of chilling). Additionally compressed air can be produced simultaneously produc- ing chilling (5000 cfm produces 1.2 MW chilling) and motive force, engines for equipment would produce cool clean air as exhaust with about 1/3 motive power to 2/3 chilling. Results obtained from a bench scale prototype system, demonstrates the rapid response of the air flow to chilling. Using a cryogenic fluid to chill a deeper mine only requires a longer pipe when the mine depthis increased and the liquid is piped so the system can provide chilling where it is needed, which is cost effective.
DPE Poster Session & Student Poster Competition Finals (5) | Session d’affiches DEP et finales du concours d’affiches étudiantes (5) / 2862
12 - Selective Assessment in Introductory Physics Labatorials
Authors: Mandana Sobhanzadeh1; Peter Zizler1
1 Mount Royal University
Corresponding Authors: [email protected], [email protected]
Some instructors choose to discard the worst tests written by the student in their assessments. They calculate the mean of the best tests as opposed to the mean of all tests written. Naturally, this process will result in some expected grade inflation. In this presentation, we introduce the selection of the best k test/reflective writing scores from the n tests/reflective writing activities writtenin introductory physics laboratories. We will share the concerns about reflective writing and post- tests evaluations as well as the problems associated with students missing labs and will introduce a selective assessment methodology to address these issues. We will discuss that using the selective assessment methodology in physics labs and courses has been beneficiary to both instructors and students and has improved students’ satisfaction.
W2-4 Fields and Strings II (DTP) | Champs et cordes II (DPT) / 2864
Detecting Lorentz invariance violations with a quantum cavity
Author: Sanjeev SeahraNone
Corresponding Author: [email protected]
We study a scalar field in a 1D quantum cavity governed by a non-Lorentz invariant action.We demonstrate that the energy levels depend on the velocity of the cavity’s walls with respect to a preferred frame, which is a stark violation of the principle of relativity.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2865
33 - Optical feedback tweezers
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Author: Avinash Kumar1
Co-author: John Bechhoefer 2
1 Student 2 Professor
Corresponding Authors: [email protected], [email protected]
We combine optical tweezers with feedback to impose arbitrary potentials on a colloidal particle. The feedback trap detects a particle’s position, calculates a force based on an imposed \virtual potential,” and shifts the trap center to generate the desired force. We create virtual harmonic and double-well potentials to manipulate particles. The harmonic potentials can be chosen to be either weaker or stiffer than the underlying optical trap. We show that we can create a virtual double-well potential with fixed well separation and adjustable barrier height. These are accomplished at length scales down to 11 nm, a feat that is difficult or impossible to create with standard optical-tweezer techniques such as time sharing, dual beams, or spatial light modulators.
T4-5 Topological materials (DCMMP) | Matériaux topologiques (DPMCM) / 2866
Connecting Superconductivity and Quantum Criticality with the High-Field Hall Effect in a Strange Metal
Author: James Analytis1
1 University of California, Berkeley
Corresponding Author: [email protected]
Unconventional superconductivity, and high−Tc superconductivity in particular, remains one of the most distinctively intractable prob- lems in physics. The existence of a common phenomenology which links these materials into a class known as “strange metals, provides hope that there is uni- fying theory that describes them. In this letter, we show that the Hall effect of the unconventional superconductor BaFe2(As1−xPx)2contains an anomalous contri- bution arising from the correlations within the strange metal. By leveraging the dependence of the Hall coefficient at high magnetic fields we are able to map the evolution of the strange metal, giving a quantitative measure of the correlated contribution in a manner that is not possible from studying the temperature dependence alone. In this way we can show that superconductivity is connected to the zero temperature physics of the strange metal phenomenology, and that the this strange metallic behavior must arise from fluctua- tions of a nearby quantum critical point. These observations create a clear but unexpected picture of strange metals that reframes our understanding of the relationship between strong correlations, quantum phase transitions and superconductivity.
T3-8 Radiation Therapy (DPMB) | Radiothérapie (DPMB) / 2867
Breast radiotherapy in a single day: innovation advancing clini- cal care
Author: Michelle Hilts1
1 BC Cancer; University of British Columbia
Corresponding Author: [email protected]
In 2012 BC Cancer became only the second institution worldwide to offer a novel radiation treatment for early stage breast cancer called Permanent Breast Seed Implant (PBSI). Briefly, patient specific
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treatment plans are designed that use strands of radioactive Pd-103 sources to deliver a prescription dose of 90Gy to the target region. Treatment consists of an operation where needles, pre-loaded with the planned sources, are used to permanently implant the Pd-103 into the breast guided by a template grid and freehand ultrasound imaging. Completed in a single outpatient session, PBSI is highly attractive to breast cancer patients compared to the standard 3.5 – 5 weeks of whole breast radiation therapy. However, at present this implant technique is technically challenging and largely limited to implementation by highly experienced clinical practitioners. Our research team is focused on developing tools and techniques aimed at reducing technical barriers to PBSI, with the goal of helping to enable widespread assess to breast seed implant for breast cancer patients. This talk will introduce PBSI and our experience with this advanced radiation treatment technique, present dosimetry results for our first 50 patients, and describe ongoing research efforts in developing 3D ultrasound for implant guidance and standardized, relevant dose reporting.
T4-4 PPD Poster Slam (PPD) | Avant-première des affiches (PPD) / 2868
Poster Slam Talks, click to see list; abstracts can be seen in Tues. PPD Poster Session
7 minute talks by some of the poster presenters Schedule: Pierre Gorel - Calibrating an ultra-low bacground detector: DEAP rising to the challenges William Woodley - Expected Neutron Background for the PICO-500 Detector with Geant4 Simula- tions Hector Hawley Herrera - Scintillating Bubble Chamber for Detecting Dark Matter Andréa Gaspert - On the Neutrino Floor for the Next Generation of Liquid Noble Dark Matter Ex- periments Jamie Grove - AmBe Source Calibrations in Measuring Reactor Antineutrinos in SNO+ Water Phase Blair Jamieson - EMPHATIC detector development Caleb Miller - Measurement of SuperKEKB Electron Beam Polarization through Tau Forward-Backward Polarization Asymmetry
W-PLEN2 EDI Plenary Session | Session plénière - M. Smith, U. Alberta / 2870
“Why we can’t wait: The urgency of diversity and decoloniality in our times” / « Pourquoi ne peut-on attendre? : L’urgence de la diversité et de la décolonisation à notre époque »
Author: Malinda Smith1
1 University of Alberta | ’Université de l’Alberta
This lecture will discuss why, despite over three decades of expressed commitment to equity, di- versity and inclusion, there are few, if any, Canadian universities, departments, or disciplines that can be held up as exemplars of EDI. Most universities’ approach to EDI seem compliance-based, driven primarily, if not exclusively, by external requirements (e.g. Employment Equity Act, Federal Contractor’s Program, CRC Program). Today, more than ever, there is an urgency for universities to go well beyond compliance to meet the intersecting challenges of equity, diversity and decolo- niality. While some scholar-activists juxtapose diversity and decoloniality, this lecture will argue that the two are interconnected and a more equitable academy is a more diverse one, and there can be no decolonized academy that is not, at the same time, more diverse and equitable. Among the urgent challenges to be addressed include leadership diversity, disaggregated and intersectional equity data, and a decolonized curriculum connected to both a diversity of bodies and bodies of knowledges.
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Dans cette allocution, j’examinerai pourquoi, malgré plus d’une trentaine d’années d’engagement exprimé en équité, diversité et inclusion (EDI), le Canada compte peu d’universités, de départements ou de disciplines qui peuvent être cités en exemples d’EDI. L’approche de la plupart des universités à l’EDI semble fondée sur la conformité, axée principalement, voire exclusivement sur des exigences extérieures (p. ex., la Loi sur l’équité en matière d’emploi, le Programme de contrats fédéraux et le Programme des chaires de recherche du Canada). Aujourd’hui plus que jamais, il est urgent que les universités aillent bien au-delà de la conformité pour atteindre les enjeux transversaux de l’équité, de la diversité et de la décolonisation. Certains grands activistes juxtaposent diversité et décolonisation, mais cette allocution révélera que ces deux éléments sont interconnectés et qu’une académie plus équitable est plus diverse, et qu’il ne peut y avoir d’académie décolonisée qui ne soit pas, du même coup, plus diverse et équitable. Parmi les enjeux urgents auxquels s’attaquer, citons la diversité du leadership, les données ventilées et intersectionnelles sur l’équité ainsi qu’un programme décolonisé lié à la fois à une diversité d’ensembles et d’ensembles de savoirs.
M1-7 Identity and Physics Education (DPE/CEWIP) | Identité et enseignement de la physique (DEP/CEFEP) / 2872
NSERC’s Dimensions: Equity, Diversity, and Inclusion Canada and Other EDI Initiatives
Author: Anne Webb1
1 NSERC
Corresponding Author: [email protected]
NSERC’s Senior Policy Advisor on EDI will provide an overview of the agency’s EDI-related initia- tives, with a specific focus on the made-in-Canada version of the UK Athena SWAN program being launched to encourage and recognize commitments made by post-secondary institutions towards advancing equity, diversity and inclusion in the research community. This program is broader in scope than what has been done so far in other countries. All post-secondary institutions will be invited to participate (universities, colleges, CÉGEPs, polytechnics), the program will encompass all academic disciplines, and it is inclusive of all underrepresented and disadvantaged groups (including, but not limited to women, Indigenous Peoples, persons with disabilities, visible minority/racialized groups and members of LGBT2Q+ communities). Following a short presentation the speaker will welcome questions from the audience.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2873
67 - Meson-Hybrid Mixing in Vector and Axial Vector Charmo- nium
Authors: Derek Harnett1; Tom Steele2; Alex Palameta3; Josha Ho1
1 University of the Fraser Valley 2 U of Saskatchewan 3 University of Saskatchewan
Corresponding Authors: [email protected], [email protected], [email protected], [email protected]
Hybrid mesons are hypothesized hadrons containing a constituent quark, antiquark, and gluon. De- spite nearly 50 years of searching, hybrids have not yet been conclusively observed in experiment.
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Part of the problem could be due to hadron mixing, the idea that observed hadrons are actually su- perpositions of conventional mesons, hybrid mesons, and other combinations of constituents. To explore this idea, we look to the vector and axial vector charmonium-like resonances. Using the QCD sum-rules methodology, we test observed resonances for coupling to a meson-hybrid cross- correlator. Resonances which couple to both currents can be interpreted as evidence for meson- hybrid mixing.
DAMOPC Poster Session & Student Poster Competition Finals (26) | Session d’affiches DPAMPC et finales du concours d’affiches étudiantes (26) / 2874
43 - A Stern-Gerlach separator of chiral enantiomers based on the Casimir-Polder potential
Authors: Fumika Suzuki1; Takamasa Momose1; Stefan Buhmann2
1 University of British Columbia 2 Albert-Ludwigs-Universitat Freiburg
Corresponding Author: [email protected]
We propose a method to separate enantiomers using parity violation in the Casimir–Polder potential between chiral mirrors and chiral molecules. The proposed setup involves a molecular beam com- posed of chiral molecules passing through a planar cavity consisting of two chiral mirrors. Enan- tiomers of opposite handedness are deflected differently due to a chiral dependence of the Casimir– Polder potential resulting in the separation of the enantiomers. Our setup provides an alternative experimental tool for enantiomer separation, as well as shedding light on the fundamental properties of the Casimir-Polder potential.
DTP Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPT et finales du concours d’affiches étudiantes (4) / 2875
23 - Discrete Self-Similar Solutions in Bianchi-IX Spacetimes
Author: David Hobill1
1 University of Calgary
Corresponding Author: [email protected]
It is known that the Friedmann-Robertson-Walker cosmologies exhibit continuous self-similarity. In addition critical gravitational collapse with non-zero energy momentum tensor sources in asymp- totically flat space-times are discretely self-similar. It will be shown that discrete self-similarity can arise in the evolution of spatially homogeneous but anisotropic vacuum cosmological models. The lowest order self-similarity is associated with period-3 oscillations which indicate that the generic time dependence will be chaotic. These solutions also lead to parameters that are related tothe golden ratio. Self similar oscillations also exist with higher periodicities and these are thought to lead to parameters related to the so-called “silver ratios”.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2876
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68 - K+ to pi+ nu nubar - First result from the NA62 experiment
Author: Bob Velghe1
1 TRIUMF
Corresponding Author: [email protected]
The accurate measurement of the very rare K+ → π+νν decay branching ratio will allow us to probe the flavour sector of the Standard Model (SM) up to unprecedented energy scales. Thanks to the process particular structure, the branching fraction can be calculated very precisely within the SM. The current best prediction is B (K+ → π+νν) = (8.4 ± 1.0) × 10−11, where most of the uncertainty is propagated from CKM matrix elements entering the computation. The observation of any deviation from the theoretical value would signal the presence of physics beyond the Standard Model. The CERN NA62 experiment aims reach a 10% relative uncertainty on the branching ratiobyus- ing a novel decay-in-flight technique. Sub-nanosecond timing resolution, hermetic photon vetoes, measurement of incoming K+ and outgoing π+ momentums, and redundant particle identification systems are key to achieve the required 10:1 signal to background ratio. The first NA62 K+ → π+νν results obtained with 2% of the data collected during the 2016-2018 period are presented. One signal candidate was found while the expected background is 0.152 event. This translates to the upper limit B (K+ → π+νν) < 14 × 10−10 at 95% CL.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2877
80 - The Axion Quark Nugget Dark Matter Model: Size Distribu- tion and Survival Pattern
Authors: Shuailiang GeNone; Kyle LawsonNone; Ariel ZhitnitskyNone Corresponding Author: [email protected]
We consider the formation and evolution of Axion Quark Nugget dark matter particles in the early universe. The goal of this work is to estimate the mass distribution of these objects and assesstheir ability to form and survive to the present day. We argue that this model allows a broad range of parameter space in which the AQN may account for the observed dark matter mass density, naturally explains a similarity between the “dark” and “visible” components, i.e. Ωdark ∼ Ωvisible, and also offer an explanation for a number of other long standing puzzles such as “Primordial Lithium Puzzle” and “the Solar Corona Mystery” among many other cosmological puzzles.
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2878
90 - Atmospheric plume dynamics of a picosecond infrared laser with applications in surgery and biodiagnostics with mass spec- trometry
Author: Esther Yung Huei LinNone Corresponding Author: [email protected]
In principle, lasers allow surgery at the single cell limit. But in practice, shock waves and ther- mal damage still pose problems. We have employed a picosecond infrared laser lasing at the water
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absorption peak at 3um to excite water molecules under desorption by impulsive vibrational exci- tation, leading to ablation processes faster than thermal and acoustic energy transfers. This rapid process greatly reduces the amount of scar tissue when compared to incisions made with scalpels or conventional medical lasers. By selectively exciting the water molecules, intact functional biologi- cal entities can be extracted and used for biodiagnostics with mass spectrometry. The combination of rapid ablations and molecule extractions allow for real-time molecular feedback during surgery. The ablation process consists of shock front expansions and material ejections that result inaplume. These nanosecond-long dynamics are captured using bright-field microscopy, allowing us toextract the velocity of the shockwave through images captured at different timings. We observe and char- acterize plume shapes as a function of laser fluences and material, some of which are liquid water, ice, liquid acetone, and liquid toluene.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2879
69 - Quasi-Monoenergetic Neutron Beams for Characterizing Dark Matter Detectors
Author: Jean-François Caron1
1 Queen’s University
Corresponding Author: [email protected]
Many designs of dark matter detectors rely on ionization from a nuclear recoil. An essential char- acteristic of these detectors is the quenching factor: the ratio of energy deposited via ionization in the detector by a particle of a given energy via nuclear recoil to that via electronic recoil. The electronic response is straightforward to measure using radioactive sources. The obvious way to characterize the nuclear response is bombardment with low-energy neutrons, but most easily avail- able sources are broad-spectrum in nature and have relatively low rates for safety and regulatory purposes. We aim to establish at the Queen’s University Reactor Materials Testing Laboratory (RMTL)[1] a quasi-monoenergetic neutron beam in order to characterize the detectors used by the NEWS-G collaboration. Eventually this could become a user facility for use by operators of other dark matter detectors.
RMTL has a 4 MV tandem accelerator which can deliver proton currents up to 45mu;A with a maximum energy of 8 MeV. Using nuclear targets such as Lithium Fluoride or Vanadium, one can produce neutrons of various energies. By accepting only a narrow slice of the neutron emission angle, the width of the energy distribution can be made arbitrarily small. The neutron fluence is strongly dependent on the beam energy and target material, but the relatively high beam current can yield rates of 1.5x105even near threshold. RMTL has a Nested Neutron Spectrom- eter[2] which can be used to characterize the produced neutron beam, and a backing detector will be installed for coincidence measurements.
We hope to demonstrate a beam of 100plusmn;20 keV neutrons over the summer of 2019, with an end goal of 30plusmn;10 keV. This low-energy quasi-monoenergetic neutron beam will allow us to measure quenching factors at sub- keV nuclear recoil energies.
This poster will introduce the NEWS-G detectors and concepts, the RMTL facility itself, the technique to produce neutrons, and the latest progress towards our goals.
[1] Queen’s University https://rmtl.engineering.queensu.ca/
[2] Maglieri, R. et al. (2015), Measuring neutron spectra in radiotherapy using the nested neutron spectrometer. Med. Phys., 42: 6162-6169. doi:10.1118/1.4931963
T2-6 Working as an Industrial, Professional, or Applied Physicist AM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué AM-2 (DPAI) / 2880
Deep Generative Models and Applications to Physics
Author: Payam Mousavi1
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1 MDA / MAXAR
Generative models leveraging the recent advances in Deep Neural Networks (DNNs) have enabled incredible applications in diverse fields such as, machine vision, speech, and finance. After giving a brief historical perspective, this presentation introduces the concepts and principles behind deep generative models, focusing mainly on an important sub-class, namely, Generative Adversarial Net- works (GANs). Using selected examples, we briefly explore applications of generative models to problems in physics and their implications. The presentation concludes with recent results using GANs for image synthesis and manipulation of satellite imagery to facilitate the training of object detection/segmentation networks.
T2-6 Working as an Industrial, Professional, or Applied Physicist AM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué AM-2 (DPAI) / 2881
Quantum computing with the D-Wave processor
Author: Allison MacDonald1
1 D-WAVE
To be provided later.
T2-6 Working as an Industrial, Professional, or Applied Physicist AM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué AM-2 (DPAI) / 2882
Commercial Career Physicists
Author: Ian D’Souza1
1 Honeywell
Corresponding Author: [email protected]
The future can seem uncertain for those contemplating private/commercial sector jobs aftergrad- uating with a degree in physics. When graduates finally realize that their physics education has taught them some useful skills, and given them knowledge beyond the laws of physics, they become more confident. Hidden in their training are abilities that are useful to the outside world, andwith some polishing and filling in the gaps, their job prospects excellent. But, there are many ‘wake-up’ moments along the way.
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2883
Honeywell
Attending Industry Panel.
Page 235 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2884
MDA / MAXAR
Attending Industry Pane
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2885
MDA / MAXAR
Attending Industry Pane
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2886
D-Wave
Attending Industry Pane
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2887
Broadcom
Attending Industry Panel.
T3-6 Working as an Industrial, Professional, or Applied Physicist PM-1 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-1 (DPAI) / 2888
Insight Data Science (Intro)
TBC
Page 236 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
T3-6 Working as an Industrial, Professional, or Applied Physicist PM-1 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-1 (DPAI) / 2889
Honeywell
Author: Gertjan Hofman1
1 Honeywell
TBC
T3-6 Working as an Industrial, Professional, or Applied Physicist PM-1 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-1 (DPAI) / 2890
D-Wave
TBC
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2891
Broadcom
Attending
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2892
Honeywell
Attending.
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2893
D-Wave
Attending.
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2894
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MDA / MAXAR
Attending.
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2895
Honeywell
Corresponding Author: [email protected]
Attending.
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2896
CanMind
Corresponding Author: [email protected]
Attending.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2897
81 - Measurement of IceCube Dom Performance Using Atmospheric Muons
Author: Nicholas Kulacz1
1 University of Alberta
Corresponding Author: [email protected]
The IceCube Neutrino Observatory is a large volume neutrino detector located two kilometers be- low the South Pole. Over one cubic kilometer of the ice is instrumented with 5,160 Digital Optical Modules (DOM) each containing a 10 inch diameter photomultiplier tube. The DOM’s photon ac- ceptance has been measured in the lab, but does not accurately represent the behavior seen in ice. This disagreement in detector response impacts our ability to accurately reconstruct deposited en- ergy. To compensate for these in situ effects, a charge scaling factor is applied to adjust simulation to more accurately describe data. This study utilizes a sample of minimum ionizing atmospheric muons, which emit a nearly constant and known rate of Cherenkov radiation, to measure the DOM charge scaling factor.
PPD Poster Session & Student Poster Competition Finals (26) | Session d’affiches PPD et finales du concours d’affiches étudiantes (26) / 2898
82 - Search for Neutrino Trident Events in IceCube
Page 238 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Sourav Sarkar1
1 University of Alberta
Corresponding Author: [email protected]
Neutrino trident production (NTP) is a standard model (SM) sub-dominant process where two charged leptons are produced via neutrino-nucleus scattering. Presence of additional beyond standard model (BSM) vector and scalar bosons can increase NTP cross-sections significantly. Thus the observation of trident events in neutrino detectors can be used as a powerful probe into the search for new physics even if the SM contribution alone is below the detection threshold. The IceCube neutrino observatory at the South Pole is a multi-purpose Cherenkov detector which uses a cubic kilometer of Antarctic ice as its detector volume with arrays of 10-inch diameter photomultiplier tubes (PMTs) called optical modules instrumented in the ice. We can search for NTP events using atmospheric neutrinos through di-muon NTP channel which creates a distinctive double-track event topology in the IceCube detector. In this poster presentation, we demonstrate the preliminary study of neutrino trident cross section calculation, expected event rate in IceCube and the limitation of the detector resolution for double-track reconstruction which are crucial steps for the sensitivity study of BSM bosons.
DCMMP Poster Session & Student Poster Competition Finals (10) | Session d’affiches DPMCM et finales du concours d’affiches étudiantes (10) / 2899
34 - Dynamics verses thermodynamics in two-step nucleation
Author: Dean Eaton1 Co-authors: Richard K. Bowles 2; Ivan Saika-Voivod 3; Peter Poole 4
1 St. Francis Xavier University 2 University of Saskatchewan 3 Memorial University 4 St. Francis Xavier University
Corresponding Author: [email protected]
Nucleation is the process by which a bulk metastable phase undergoes a phase transition to a stable phase via the formation of a local fluctuation (the critical nucleus) of sufficient size to beableto grow spontaneously to macroscopic scale. In the case of “two-step nucleation” (TSN), the first step in the phase transformation process consists of the appearance in the bulk metastable phase of a local fluctuation that resembles an intermediate phase distinct from the stable phase. In the secondstep of TSN, this intermediate fluctuation undergoes a transition in which the stable phase emerges from within the intermediate phase. Evidence for TSN has been observed experimentally in a wide range of molecular and colloidal systems, including important cases relevant to understanding protein crystallization and biomineralization. In a recent work, the free energy surface (FES) describing TSN as it occurs in a simple 2D model of a metamagnet was evaluated [1]. This FES shows that at a well- defined size for the growing nucleus, the stable phase becomes more stable than the intermediate phase, providing a thermodynamic prediction for the nucleus size at which the second step of TSN begins. Here we identify conditions at which the spontaneous transition within the nucleus occurs at much larger size than predicted by thermodynamics, demonstrating that the system dynamics can have a dramatic impact on how TSN is observed in practice.
M-MEDAL1 - CAP Teaching Medal l Médaille d’enseignement de l’ACP - Robert Mann, U. Wa- terloo / 2900
Physics for Novice and Expert / La physique pour novices et ex- perts
Page 239 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Author: Robert Mann1
1 University of Waterloo
Corresponding Author: [email protected]
Physics, the ultimate interdisciplinary science, is a challenge to learn. Conceptually counterintuitive, technically formidable, and creatively demanding, it can intimidate even the most seasoned veteran. Our task as physics teachers is to guide our students along this path, from their original exposure to the subject to their completion of its most advanced degrees. We will best succeed by realizing that our greater mandate is to bring an understanding of physics to as broad an audience as possible. This requires a range of pedagogical strategies that will best engage the scientific curiosity ofthe audience at hand. I propose that it is by teaching physics at all levels — from the youngest novice to the talented expert — that we will not only achieve excellence in undergraduate teaching at all levels, but will awaken a wider public into seeing that physics is both a wonder to discover and a joy to teach.
La physique, science interdisciplinaire ultime, pose un défi d’apprentissage. Contraire à la logique théorique, formidable sur le plan technique et ambitieuse du point de vue création, elle peut in- timider même le vétéran le plus aguerri. À titre de professeurs de physique, notre tâche est de guider nos étudiants dans cette voie, dès qu’ils abordent ce sujet jusqu’à l’obtention des diplômes les plus avancés. Notre plus grande réussite sera de constater que notre mandat ultime est de faire comprendre la physique au plus vaste auditoire possible. Cela exigera une gamme de stratégies pédagogiques qui saura mieux éveiller la curiosité scientifique de l’auditoire. À mon avis, c’est en enseignant la physique à tous les niveaux — du plus jeune novice à l’expert talentueux — que non seulement nous atteindrons l’excellence en enseignement à tous les niveaux du premier cycle, mais que nous amènerons un plus vaste public à voir dans la physique tant une merveille à découvrir qu’un plaisir à enseigner.
W-MEDAL2 CAP-DCMMP Brockhouse Medal Talk | Médaile Brockhouse - Graeme Luke, Mc- Master U. / 2901
Probing Superconductivity and Magnetism in Quantum Materi- als with Muons / L’exploration de la supraconductivité et du mag- nétisme des matériaux quantiques contenant des muons
Author: Graeme Luke1
1 McMaster University
Corresponding Author: [email protected]
Quantum materials are systems where electronic interactions give rise to emergent new electronic states of matter which can include topological order, high temperature superconductivity, topolog- ical superconductivity, quantum spin liquids and spin ices. Classifying and understanding these behaviours often requires sensitive measurements of their magnetic properties. Muon spin rota- tion/relaxation is a real-space microscopic precision probe of magnetism and ideally suited for the study of quantum materials. We have used SR to identify broken time reversal symmetry in the heavy fermion superconductor UPt3 and the probable chiral p-wave superconductor Sr2RuO4. Ge- ometrically frustrated magnets where the lattice geometry prevents all pair-wise interactions tobe simultaneously satisfied can host a wide variety of novel magnetic ground states. We have used SR to search for emergent magnetic monopoles in spin ice and to identify potential quantum spin liq- uid states. We are developing new SR capabilities at TRIUMF which include new general purpose spectrometers and a high pressure/low temperature facility which will greatly enhance our ability to study new quantum materials in the near future.
Page 240 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Les matériaux quantiques sont des systèmes dont les interactions électroniques donnent à la matière de nouveaux états électroniques pouvant comprendre l’ordre topologique, la supraconductivité à haute température, la supraconductivité topologique, les liquides de spins quantiques et les glaces de spins. Classifier et comprendre ces comportements exigent souvent des mesures délicates des propriétés magnétiques. La rotation/relaxation du spin des muons est une perception de précision microscopique du magnétisme, en espace réel, et convient particulièrement bien à l’étude des matéri- aux quantiques. Nous avons eu recours à SR pour identifier la symétrie du temps fractionné inverse dans le supraconducteur à fermions lourds UPt3 et le supraconducteur chiral à onde P probable Sr2RuO4. Les aimants géométriquement frustrés, dont la structure en treillis empêche l’exécution simultanée de toutes les interactions par paires, peuvent contenir une grande variété de nouveaux états magnétiques normaux. Nous avons fait appel à SR pour chercher de nouveaux monopoles magnétiques dans les glaces de spin et identifier les états possibles de liquides de spins quantiques. Nous énonçons de nouvelles possibilités SR à TRIUMF, ce qui inclut de nouveaux spectromètres d’usage général et une installation à haute pression/faible température qui améliorera grandement notre capacité à étudier les nouveaux matériaux quantiques dans un proche avenir.
R-MEDAL2 CAP-CRM Prize Talk | Prix ACP-CRM - Jaume Gomis, Perimeter Institute | Institut Périmètre / 2902
Nonperturbative dynamics of 2+1d Gauge Theories / Dynamique non perturbatrice des théories de jauge 2+1d
Author: Jaume Gomis1
1 Perimeter Institute for Theoretical Physics
Corresponding Author: [email protected]
We discuss the recently proposed strongly coupled infrared dynamics of QCD theories in 2+1 di- mensions. These theories emerge at the intersection of condensed matter physics, particle physics and mathematics. The nonperturbative infrared dynamics of these theories exhibits remarkably rich phenomena.
Nous examinons la dynamique infrarouge fortement couplée des théories QCD de dimensions 2+1 proposées récemment. Ces théories ressortent au point de confluence de la physique de la matière condensée, de la physique corpusculaire et des mathématiques. La dynamique non perturbatrice de ces théories révèle des phénomènes remarquablement riches.
W-MEDAL1 CAP Herzberg Medal Talk | Médaille Herzberg de l’ACP - Paul Barclay, U. Calgary / 2903
Diamond nanophotonics: using light to talk to phonons and spins / Dispositifs nanophotoniques à diamants faisant interagir la lu- mière sur les phonons et les spins
Author: Paul Barclay1
1 University of Calgary
Corresponding Author: [email protected]
Nanophotonic devices enhance light-matter interactions by confining photons to small volumes. This can enable coherent optical coupling to a wide range of quantum systems, including single
Page 241 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
“artificial atoms” that serve as qubits for quantum information processing in crystals suchasdia- mond. They also allow coherent “cavity optomechanical” manipulation of vibrations in nanoscale resonators, leading to applications ranging from sensing to storing light and creating quantum mem- ories. I will talk about my group’s efforts to demonstrate diamond nanophotonic devices that si- multaneously couple light to both artificial atom electronic spins, and to nanomechanical systems, which involves surmounting challenges ranging from nanophotonic device design and fabrication to development of new measurement techniques.
Les dispositifs nanophotoniques améliorent les interactions lumière-matière en confinant les pho- tons à de faibles volumes. Cela peut permettre un couplage optique cohérent à une grande diversité de systèmes quantiques dont les « atomes artificiels » seuls qui servent de qubits pour le traitement de l’information quantique dans le cristal, tel le diamant. Cela permet aussi une manipulation co- hérente « optomécanique de cavités » des vibrations dans des résonateurs à l’échelle nanométrique, menant à des applications allant de la détection au stockage de la lumière et à la création de mémoire quantique. Je décrirai les efforts de mon groupe pour démontrer les dispositifs nanophotoniques à diamants qui, à la fois, couplent la lumière aux spins électroniques d’atomes artificiels, aux systèmes nanomécaniques, ce qui oblige à surmonter les défis allant de la conception et fabrication de disposi- tifs nanophotoniques au développement de nouvelles techniques de mesure.
M-MEDAL2 CAP Lifetime Achievement Medal | Médaille pour contributions exceptionnelles de carrière - Doug Bonn, U. British Columbia / 2904
A Journey from Superconductivity to Teaching Reasoning in First- Year Labs / De la quête de la supraconductivité à l’enseignement du raisonnement en première année de laboratoire
Author: Doug Bonn1
1 Univ. of British Columbia
Corresponding Author: [email protected]
The discovery of new superconductors often precipitates a race to identify the superconducting pair- ing state and clues to the mechanism driving the superconductivity. The journey is often a complex one, involving sample quality challenges, and a wide array of competing spectroscopic and ther- modynamic techniques. I will give snapshots of this trail, highlighting the importance of materials growth, plus spectroscopic techniques at optical and microwave frequencies, and in a scanning tun- nelling microscope. A side trip to look at the challenges of teaching scientific reasoning to first-year students will show surprising connections to the experts’ journey.
La découverte de nouveaux supraconducteurs déclenche souvent une course pour identifier l’état d’appariement des supraconducteurs et des indices du mécanisme déclenchant la supraconductivité. La quête est souvent complexe, comportant des défis de qualité d’échantillons et un vaste éventail de techniques spectroscopiques et thermodynamiques concurrentielles. Je donnerai un aperçu de cette démarche, faisant ressortir l’importance de la croissance des matériaux, ainsi que des techniques thermodynamiques à des fréquences optiques et micro-ondes, et dans un microscope à balayage à effet tunnel. Un détour par les difficultés d’enseigner le raisonnement scientifique aux étudiantsde première année montrera d’étonnants rapports avec la quête des experts.
R-MEDAL1 CAP-TRIUMF Vogt Medal Talk | Médaille Vogt de l’ACP-TRIUMF - Scott Oser, U. British Columbia / 2905
Page 242 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Weakly probing the universe across nine decades in energy / Ex- ploration sommaire de l’Univers sur neuf ordres de grandeur en énergie
Author: Scott OserNone
Corresponding Author: [email protected]
The typical particle in the universe wants nothing to do with us. Neutrinos are the most numerically dominant of Standard Model particles, but we can live our lives scarcely aware of their existence. Dark matter particles outweigh the Standard Model’s contribution in our universe’s energy budget by a factor of five, yet their elusiveness makes neutrinos seem like shameless extroverts. Overthe last two decades I’ve explored the most elusive particles in nature at part of the SNO, T2K, and SuperCDMS experiments, probing physics over a range of energy scales spanning nine orders of magnitude. In this talk I’ll explore the unique challenges that these experiments have presented, and the exciting things they have taught us about the universe.
La particule typique de l’Univers n’a rien à voir avec nous. Les neutrinos prédominent en nombre sur les particules du modèle standard, mais notre vie peut se passer sans que nous n’en remarquions guère l’existence. L’apport des particules de matière noire surpasse de 5 fois celui des particules du modèle standard dans l’inventaire énergétique de notre univers et pourtant, la fugacité des neu- trinos en fait des extravertis sans vergogne. Les deux dernières décennies m’ont amené à explorer les particules les plus fugaces de la nature dans le cadre des expériences du SNO, du T2K et du SuperCDMS, explorant la physique sur un ensemble d’échelles d’énergie couvrant neuf ordres de grandeur. Mon propos permettra de voir les défis uniques que ces expériences ont présentés etles choses passionnantes qu’elles nous ont apprises au sujet l’Univers.
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2906
88 - Multi-seeded MD simulation to effectively sample the con- formation space of short peptide
Authors: Ching-chung Hsueh1; Aina Adekunle1; Steven Plotkin2
1 University of British Columbia 2 UBC
Corresponding Authors: [email protected], [email protected]
We propose a method–multi-seeded MD (molecular dynamics) simulation–to effectively sample the conformational space of short peptides. Multi-seeded simulations prepare an exhaustive set of dis- tinct initial conformations by assigning uniformly-distributed phi/psi angles for each amino acid. These distinct conformations act as seeds for subsequent short relaxation simulations. Weapply this method to several short cyclic peptides, including scaffolded epitopes of Abeta and Tau protein. The results show that CPU requirements and simulation time are reduced, but sampling thephase space is comparable, when comparing to REMD (replica exchange molecular dynamics). The multi- seeded method can sample structures rarely explored in REMD and normal MD simulation.
M2-7 Nelson Session: An Integrative, Student-Centered Approach to Teaching Today’s Physics and Astronomy Students (DPE) | Session Nelson (DEP) / 2907
An Integrative, Student-Centered Approach to Teaching Today’s Physics and Astronomy Students
Page 243 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Authors: Paul Fam1; Tia Nguyen1
1 Nelson
As Tony Bates once said, “nothing has changed more in higher education over the last 50 years than the students themselves.” Join us for a dynamic discussion around inclusive, innovative, and evidence-based teaching approaches, and how you could transform your classroom lectures and be inspired by the way your students consume and retain information. This session will be full of thought-provoking ideas that could easily be implemented in your classrooms tomorrow.
M2-7 Nelson Session: An Integrative, Student-Centered Approach to Teaching Today’s Physics and Astronomy Students (DPE) | Session Nelson (DEP) / 2908
So They Think They Hate Physics … Building Confidence in1st Year Science Students
Author: Joanne O’Meara1
1 University of Guelph
Corresponding Author: [email protected]
When biological science students walk through the physics lecture room door on their first day at the University of Guelph, they generally fall into one of two categories: terrified or ambivalent. Almost no one is excited to be there, as they’ve been putting off taking physics for as long as possible. Knowing this, we have designed our service courses so that by the end of week 12 they have a much greater appreciation for our discipline. Many even go so far as to say that our class was their favourite course of the semester! Come and find out more about our approach to building up confidence in first-year science students at the University of Guelph.
M2-7 Nelson Session: An Integrative, Student-Centered Approach to Teaching Today’s Physics and Astronomy Students (DPE) | Session Nelson (DEP) / 2909
Implementing Innovation in Physics Teaching and Learning
Authors: Marina Milner-Bolotin1; Robert Hawkes2
1 The University of British Columbia 2 Mount Allison University
Corresponding Authors: [email protected], [email protected]
A wealth of physics education research in recent decades has helped identify innovations that offer the most promise for truly effective physics learning. There is no doubt that active learning, mas- tery of concepts coupled with student self-checks, effective use of technology, and problems that challenge without overwhelming are all important components. Active learning will naturally hap- pen when students are sufficiently engaged with the topics and the environment, but howdowe really foster that? Working as part of a collaborative author team, self-reflection, and writing about physics has been an effective way for us to learn insights on both physics and learning. Wewill share ideas on how you might apply similar experiences to your own physics classrooms.
T3-6 Working as an Industrial, Professional, or Applied Physicist PM-1 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-1 (DPAI) / 2910
Page 244 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Extended Lunch Panel | panneau déjeuner prolongé
Student Session : Industry Meet & Mingle | Session étudiante - Rapprochement industriel / 2911
Insight Data Science
Representative Attending.
Student Lunch Session Panel ”Working as a Physicist in the Private Sector” (Associated with Working as Industrial, Professional, or Applied Physicists Symposium) | Session du dîner pour étudiants ”Travailler comme physicien dans le secteur privé” (associée avec le Symposium sur le travail comme physiciens industriel, professionnel, ou appliqué / 2912
Director of Professional Affairs, CAP
Corresponding Author: [email protected]
Attending.
T3-9 Cosmology (DTP) | Cosmologie (DPT) / 2913
A critical analysis of the CMB: constraining CMB physics with peaks, valleys, and saddles
Author: Dagoberto Contreras1
1 York University
Corresponding Author: [email protected]
Data analysis of the cosmic microwave background is often performed by making a map of the sky and then converting that map into its spherical harmonics. This is done because the expectation is that the spherical harmonic coefficients are Gaussian random variables, and the data agrees with this prediction extremely well. In this talk I will discuss a less often used map space approach. The approach requires finding extremal points in a map and stacking images of the CMB temperature and polarization around these points. In general this approach has equivalent constraining power to harmonic approaches though it deals with systematic effects in different ways. I show the simplicity and utility of this technique using specific models. I further extend this approach to include (never before used) saddle points and demonstrate that in certain cases they can be more constraining than extremal points.
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2914
89 - Mechanical, chemical, structural, and radiological changes in pigeon bone, associated with the dietary intake of nickel recovery
Page 245 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts slag as a grit source.
Authors: Michel Lapointe1; Eduardo Galiano-Riveros1
1 Laurentian University
Corresponding Authors: [email protected], [email protected]
Slag from nickel smelting operations in the Sudbury basin in Ontario has become ubiquitous. This material rich in heavy metals such as iron, upon ingestion has the potential to effect physical, ra- diological, chemical, mechanical, and structural changes in biological systems. In this work, we analyze the effects of slag ingestion through diet, on several quantitative and qualitative parameters of the tibio-tarsal bones in pigeons (Columba livia domestica). The specimens were divided into a control group provided a “normal” diet of clean limestone, and an experimental group fed slag-based grit, both for a period of one year. Their tibio-tarsal bones were then harvested for analysis. Quan- titative analytical methods included measurement of caliper-based cortical bone thickness of the tibia, conventional density measurements, bone mineral density measurements using Dual Energy X-ray Absorptiometry, calcium and iron concentration measurements using mass spectrometry, and the determination of Young’s Moduli and ultimate breaking strength (both in compression) using a universal testing machine. A Welch’s t test (single tail) was used to compare means of the seven quantitative parameters between control and experimental samples, and in six parameters, a statisti- cally significant difference was found (p ≤ .05). Microscopy, both optical and electron –coupledwith energy dispersive spectroscopy (EDS) was also carried out for both sample groups. Microscopy and EDS analysis revealed structural differences in bone between the two groups. We conclude thatslag ingestion through diet in the species examined, is associated with measurable changes in physical, radiological, mechanical, chemical, and structural properties of the tibio-tarsal bones.
T4-6 Working as an Industrial, Professional, or Applied Physicist PM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-2 (DPAI) / 2916
PLACEHOLDER - Insight Data Talk
T4-6 Working as an Industrial, Professional, or Applied Physicist PM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-2 (DPAI) / 2917
PLACEHOLDER - Industrial Problem Solving Workshop Talk
Entered as per Daniel Cluff
IPP AGM | AGA de l’IPP / 2918
IPP Director’s Report & Council Election Results
IPP AGM | AGA de l’IPP / 2919
European PP Strategy Update
Corresponding Author: [email protected]
Page 246 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
IPP AGM | AGA de l’IPP / 2920
Canadian Particle Physics Computing Issues
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2921
McDonald Institute Report
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2922
EXO-200 and nEXO
Corresponding Author: [email protected]
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2923
Applications - Single photo-detector landscape in Canada
Author: Fabrice Retiere1
1 TRIUMF
Corresponding Author: [email protected]
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2924
Development - 3DdSiPM
Author: Jean-Francois Pratte1
1 Université de Sherbrooke
Corresponding Author: [email protected]
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2925
Applications - nEXO, LoLX and liquid Xenon
Author: Thomas McElroy1
Page 247 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 McGill University
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2926
Development - development of VUV light detection solutions
Author: Giacomo Gallina1
1 TRIUMF
Corresponding Author: [email protected]
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2927
Applications - liquid Argon
Author: P. Giampa1
1 TRIUMF
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2928
Applications - Bubble chamber
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2929
Development - Hybrid photo-detectors
Author: Fabrice Retiere1
1 TRIUMF
Corresponding Author: [email protected]
For Alberta / Michigan Group
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2930
Ocean network
Author: Carsten Krauss1
Page 248 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
1 University of Alberta
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2931
Water Cerenkov for long baseline neutrino oscillation
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2932
Development - mPMT
Author: T. Linder1
1 TRIUMF
PPD Meeting on Detectors for Astroparticle Physics | Réunion de PPD sur les détecteurs pour la physique des astroparticules / 2933
Commercial opportunities
IPP AGM | AGA de l’IPP / 2934
T2K and HyperK
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2935
NA62
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2936
Belle II
Corresponding Author: [email protected]
Page 249 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
IPP AGM | AGA de l’IPP / 2937
PICO
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2938
ATLAS
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2939
SuperCDMS
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2940
IceCube
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2941
SNO+
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2942
DEAP
Corresponding Author: [email protected]
T4-4 PPD Poster Slam (PPD) | Avant-première des affiches (PPD) / 2943 test
Page 250 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
DPMB Poster Session & Student Poster Competition Finals (4) | Session d’affiches DPMB et finales du concours d’affiches étudiantes (4) / 2944
93 - Properties of Retinal Amyloid Deposits in Association with Alzheimer’s Disease
Author: Melanie Campbell1
Co-authors: Ji Ren 1; Erik Mason 1; Rachel Redekop 1; Laura Emptage 1; Veronica Hirsch-Reinshagen 2; Ging-Yuek Robin Hsiung 3; Ian Mackenzie 2
1 University of Waterloo 2 University of British Columbia 3 UBC Hospital Clinic for Alzheimer Disease and Related Disorders
Corresponding Authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Background: In Alzheimer’s disease (AD), amyloid deposits have been reported primarily in the far peripheral retina. In polarimetry images, we examine signal strength, location of retinal deposits and predictions from these deposits of AD associated disease changes in the brain. Methods: The severity of AD associated brain pathology was assessed (NIA guidelines) and retinas from donors diagnosed with AD (n=26) and those not (n=4) were stained with 0.1% Thioflavin-S, counter-stained with DAPI and imaged using a fluorescence microscope fitted with a polarimeter. Polarization properties of amyloid deposits were calculated. Variation in deposit density with radial distance from the optic nerve head was determined. Ignoring the far periphery, we tested the pre- diction of severity of AD associated changes in the brain by retinal deposits. Results: Amyloid deposits had linear retardance signals much stronger than the background retina. The 1014 deposits with polarization signals occurred more frequently in the peripheral retina. How- ever, the retinal area increases with radial distance from the optic nerve head. The normalized deposit densities versus radial distance were not statistically different (K-S test) for differing brain pathologies. For low and high severities of pathology, the retinal deposit densities were non-uniform with higher density in the central retina. Ignoring the far periphery, the number of retinal deposits still correlated significantly with the cumulative score of severity of AD associated brain changes (p<0.05). Conclusions: Retinal deposits imaged using polarized light have high contrast against the retina. The density of retinal deposits decreases slightly from the centre of the retina to the periphery. To predict the severity of AD pathology in the brain, deposits in the far periphery of the retina need not be imaged. This simplifies the design of live eye imaging as a biomarker ofAD.
T4-6 Working as an Industrial, Professional, or Applied Physicist PM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-2 (DPAI) / 2945
Industrial Problem Solving Workshops
Author: Sanjeev SeahraNone
Corresponding Author: [email protected]
The main goals of an Industrial Problem Solving Workshop (IPSW) are to build connections between researchers in industry, non-profit organizations, and academia. Canada’s mathematical sciences institutes have been organizing IPSWs for over twenty years. During an IPSW, non-academic or- ganizations present problems related to their interests, and academic participants will break into teams to explore solutions to these problems. Typical problems come from a variety of subject areas, but all are designed to be approachable by students and postdocs with backgrounds in pure math- ematics, modelling, scientific computing, computer science, or data analysis. Each problem group is led by university faculty members with expertise relevant to the technical challenge at hand, but participants with a wide range of interests and expertise are welcome. Over the course of the five- day workshop, problem groups work collaboratively to explore possible solution strategies to the
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technical challenges, propose longer-term research directions, and make connections to a larger net- work of companies and academic researchers with similar interests. In this talk, I will describe both the previous and upcoming IPSWs organized by AARMS (the Atlantic Association for Research in the Mathematical Sciences), and describe how students and faculty with a physics background can participate. (For more details see aarms.math.ca/ipsw2019/.)
T2-11 General Instrumentation (DAPI) | Instrumentation générale (DPAI) / 2946
Measuring antimatter gravity in the ALPHA-g magnetic trap
Author: Chukman SoNone
Corresponding Author: [email protected]
The ALPHA-g experiment at CERN aims to undertake the first ever precision measurement ofthe gravitational mass of antihydrogen atoms, by releasing them from a gravity-compensated magnetic minimum trap. The magnetic minimum trap is nominally created by an octupole and twomirror coils. However, in order to achieve the level of magnetic control required to resolve gravity to the 1% level and beyond, many other magnetic elements are involved to tailor and correct the trap field to the O(10^-5) level, as well as to manipulate and cool the anti-atoms before the measurement. In this talk, we present the construction of the sophisticated, multi-purpose superconducting magnet system designed for this purpose, which composes of 24 coils, 5 overlapping octupole elements and a high-uniformity large volume solenoid. We will also showcase the simulated behaviour of the anti- atoms inside the magnet system, as well as the predicted gravity precision we may achieve under different experimental conditions.
T4-6 Working as an Industrial, Professional, or Applied Physicist PM-2 (DAPI) | Travailler comme un physicien industriel, professionnel ou appliqué PM-2 (DPAI) / 2947
President & CEO, TRIUMF Innovations
Author: Kathryn Hayashi1
1 TRIUMF
Corresponding Author: [email protected]
Speaking.
Joint CINP-IPP Sessions (DNP/PPD) | Réunion conjointe de l’ICPN et de l’IPP (DPN-PPD) / 2948
NSERC SAPES Chair Report
Corresponding Author: [email protected]
Joint CINP-IPP Sessions (DNP/PPD) | Réunion conjointe de l’ICPN et de l’IPP (DPN-PPD) / 2949
News from CFI
Page 252 2019 CAP Congress / Congrès de l’ACP 2019 / Book of Abstracts
Corresponding Author: [email protected]
Joint CINP-IPP Sessions (DNP/PPD) | Réunion conjointe de l’ICPN et de l’IPP (DPN-PPD) / 2950
TRIUMF Director Report
Corresponding Author: [email protected]
Joint CINP-IPP Sessions (DNP/PPD) | Réunion conjointe de l’ICPN et de l’IPP (DPN-PPD) / 2951
SNOLab Director Report
Corresponding Author: [email protected]
IPP AGM | AGA de l’IPP / 2952
Close
Corresponding Author: [email protected]
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