DOCSLIB.ORG

Ardm: Liquid Argon TPC for Direct Dark Matter Detection

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ardm: Liquid Argon TPC for Direct Dark Matter Detection ArDM: Liquid Argon TPC for direct Dark Matter detection Roberto Santorelli (on behalf of the ArDM collaboration) CIEMAT - MADRID 1 DIRECT DETECTION EXPERIMENTS GOAL: Detection of the elastic (inelastic) collisions with atomic nuclei 2 Recoil q 2V 2 Er (1 cos) 50keV Ar,Xe,Ge…Nuclei energy 2mN mN (at rest) q 2 2V 2 (1cos) momentum transfer WIMP ~10-3 6 2 m mN m mN reduced mass (Flux ~10 p/cm /s) Rate R N N V <1 evt/100 kg/day Erecoil<50 keV m N = number of target nuclei in detector Scattering non relativistic : 3 3 coupling spin-dependent / spin-independent = local WIMP density ρ~0.3GeV/cm 3000/m (m=100GeV) 7 <N> = scattering cross section (10 pb) Experimental signatures: Backgrounds: • Nuclear recoils • : higher energy depositions • Featureless recoil spectrum (no bump) • : underground + veto • Single scatters •, : ER shielding + discrimination (uniform throughout the detector volume) • n : NR shielding + multiple interactions Extremely low background technique required and good discrimination NR-ER 6 (ER bkg rate > 10 higher) 2 Roberto Santorelli – MultiDark Canfranc 13/4/2012 COUPP PICASSO PHONONS CDMS, CRESST EDELWEISS ROSEBUD CHARGE LIGHT DRIFT DEAP/CLEAN GERDA ArDM DAMA,KIMS, LUX,ZEPLIN, XMASS XENON.. 3 Roberto Santorelli – MultiDark Canfranc 13/4/2012 NOBLE LIQUIDS FOR DARK MATTER DETECTION • low energy threshold Experimental requirements for DM experiments: • large mass • ultra low background • event by event discrimination High atomic number compact detectors good stopping power (i.e. self shielding active volume) High scintillation and ionization yield Nuclear recoil discrimination different charge/light ratios pulse shape discrimination Event imaging (fiducialization, multiple hits) “Easy” to purify with a variety of methods (long drift) Available in large quantity (affordable) 4 Roberto Santorelli – MultiDark Canfranc 13/4/2012 NOBLE LIQUIDS AS DETECTOR MEDIUM Element Z(A) Boiling Liquid Energy Radiation Collision Ionization Scintillation Cost point (Tb) density loss length length [e-/keV] [/keV] @Tb dE/dx (cm) @1bar [k] X0(cm) [g/cm3] (MeV/cm) Ne 10(20) 27.1 1.21 1.4 24 80 46 7 Ar 18(40) 87.3 1.40 2.1 14 80 42 40 Kr 36(84) 119.8 2.41 3.0 4.9 29 49 25 Xe 54(131) 165.0 3.06 3.8 2.8 34 64 46 5 Roberto Santorelli – MultiDark Canfranc 13/4/2012 LXe vs LAr LXe: Density Price ~50% odd isotopes ( 129Xe, 131Xe ) for spin dependent interactionsBOXING No long-lived radioactiveTHE “NOBLE” isotopes SPORT LAr: Background discrimination Radioactive isotopes Available in large quantity 39Ar 1.01 Bq/kg (NIM-A 574 (2007) 83–88) MultiDark Canfranc 13/4/2012 CanfrancMultiDark – 6 Roberto SantorelliRoberto LAr TPC Charge readout In Gas Ar Gas Ar Eg Ed Ionization charge Primary scintillation LAr interaction in LAr xy position reconstructed through the charge PMTs Z position reconstructed through the Drift time 7 Roberto Santorelli – MultiDark Canfranc 13/4/2012 ArDM-1t BASIC CONCEPTS • ~2000 kg Ar mass, ~850 kg instrumented • Cylindrical volume 80 cm diameter, ~120 cm max drift Services • 0.53 kV drift field Charge • Cryogenic low radioactivity PMT (Hamamatsu R5912) readout 14 8” in liquid (LEM/EL) 14 8” in gas (first phase) HV multiplier Field rings 2 m PMT array LAr recic. 8 Roberto Santorelli – MultiDark Canfranc 13/4/2012 NUCLEAR RECOIL DISCRIMINATION I Applying a drift field fewer and fewer electrons recombine Nuclear recoil with the parent ions : recombination light suppressed. Scintillation Charge Different track structures of recoiling electron and nuclei two different amount of quenching Different ionization/scintillation ratio for electron Electron recoil and nuclear recoil Scintillation Charge Event by Event discrimination 9 Ultra pure liquid necessary to preserve small electron signal (~10 el) Roberto Santorelli – MultiDark Canfranc 13/4/2012 NUCLEAR RECOIL DISCRIMINATION II Very large difference in decay times between fast Argon excimer (1, 3) (≈ 7 ns) and slow (1.6 µs) components of the emitted UV light. * Ar 2 128 nm The ionization density strongly affects the relative intensity of the singlet and triplet state de- excitation light . Ar Ar Unbound state Pulse shape discrimination of primary scintillation. 10 Roberto Santorelli – MultiDark Canfranc 13/4/2012 ArDM-1t TPC 11 Roberto Santorelli – MultiDark Canfranc 13/4/2012 HV system Greinacher (Cockcroft-Walton) circuit • 210 stages (1520 capacitors, 1260 diodes) in LAr • 30 field shapers (4 cm spacing) • Alternating current input (50 Hz, Vpp~2.5 kV) • Up to 400 kV (3 kV/cm field) at cathode S. Horikawa et al., J. Phys. 12 Conf. Ser 308 (2011) 012027 13 Roberto Santorelli – MultiDark Canfranc 13/4/2012 ArDM Phases • Surface operation: build and commission1-ton two-phase LArTPC at CERN [done!] • Underground operation Phase I: development of underground infrastructure (shielding etc) + science run using natural Ar [starts in 2012] • Underground operation Phase II: science run using depleted Ar [starts when sensitivity of science run with natural Ar is 39Ar limited AND a sufficient amount of depleted 39Ar is available. 2014?] 14 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Tests @ CERN • Detector successfully operated in stable conditions • Several calibration runs with external sources taken (22Na, AmBe) • New DAQ tested • Light collection and particle discrimination studies 22Na 15 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Recent upgrades • The cooling system of ArDM has been upgraded with a recondenser, with 600 W of cooling power provided by two GM cryocoolers [Cryomech AL300]. In this way we have a closed loop, zero loss system • The new system has been operated for over 7 weeks, providing a full characterization together with a MultiDark Canfranc 13/4/2012 CanfrancMultiDark stability test – • The control of the cryocoolers/cryogenic system is fully integrated in the existing PLC • Reduced manpower requirements in operating ArDM • The system is safe: in case of failure of the cryocoolers, the LAr evaporates slowly [less than 100 L/day SantorelliRoberto for the cooling bath and much less for the inner vessel] through the overpressure valve 16 2011 Tests 2011 17 Roberto Santorelli – MultiDark Canfranc 13/4/2012 18 Roberto Santorelli – MultiDark Canfranc 13/4/2012 19 Roberto Santorelli – MultiDark Canfranc 13/4/2012 ArDM @ Canfranc • ArDM under vacuum • Pumps are on MultiDark Canfranc 13/4/2012 CanfrancMultiDark – • Controlled remotely Roberto SantorelliRoberto 20 Neutron shield Three structural parts: lateral shield, top shield, bottom shield CIEMAT –ArDM team Maria De Prado Barbara Montes Luciano Romero Roberto Santorelli + technicians and “experts” 21 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Neutron shield • The lateral sides of the slab are bent in order to avoid straight paths to the heart of the ArDM detector. • The thickness of the slab is not precise: 50.5±0.5mm. • 4 slabs are glued together with silicone to make a block of 203 mm, with controlled height. • The top slab in the block has mechanical fixations. 2425 mm 22 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Slab= 20Kg Blocks (4 slabs)= 80Kg Rings (8 blocks)= 640Kg Lateral shield (600 slabs)= 12Tons 23 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Top and bottom shields Bottom shield weigth: 2.5 tons Top shield weigth: 2.5 tons 24 Roberto Santorelli – MultiDark Canfranc 13/4/2012 25 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Gamma and neutron calibration Under discussion Currently studied 26 Roberto Santorelli – MultiDark Canfranc 13/4/2012 • Simulations of the energy deposited by different sources currently carried out • Event discimination 27 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Signal and background rates Assuming: • 500 Underkg fiducial discussion mass • 107 Electron recoil rejection (103 from charge/light and 104 from pulse shape) • Shield fully in place • Recoil energy range of 30-100 keV • 50% nuclear recoil acceptance • WIMP mass 100 GeV and x-sec 10-44 cm2 39Ar Gamma Neutrons Bkg WIMP (evt/day) (evt/day) (evt/day) (evt/day) (evt/day) 1.5 106 47500 0.07 0.22 0.25 28 Before suppression After bkg suppression Roberto Santorelli – MultiDark Canfranc 13/4/2012 29 Roberto Santorelli – MultiDark Canfranc 13/4/2012 Conclusions • LAr offers very good prospects for DM direct search •ArDM-1t successfully tested on surface • Underground operations @ Canfranc started • Start of the data taking with atmospheric Ar in 2012 30 Roberto Santorelli – MultiDark Canfranc 13/4/2012 .
Load more

Recommended publications
  • European Astroparticle Physics Strategy 2017-2026 Astroparticle Physics European Consortium
    European Astroparticle Physics Strategy 2017-2026 Astroparticle Physics European Consortium August 2017 European Astroparticle Physics Strategy 2017-2026 www.appec.org Executive Summary Astroparticle physics is the fascinating field of research long-standing mysteries such as the true nature of Dark at the intersection of astronomy, particle physics and Matter and Dark Energy, the intricacies of neutrinos cosmology. It simultaneously addresses challenging and the occurrence (or non-occurrence) of proton questions relating to the micro-cosmos (the world decay. of elementary particles and their fundamental interactions) and the macro-cosmos (the world of The field of astroparticle physics has quickly celestial objects and their evolution) and, as a result, established itself as an extremely successful endeavour. is well-placed to advance our understanding of the Since 2001 four Nobel Prizes (2002, 2006, 2011 and Universe beyond the Standard Model of particle physics 2015) have been awarded to astroparticle physics and and the Big Bang Model of cosmology. the recent – revolutionary – first direct detections of gravitational waves is literally opening an entirely new One of its paths is targeted at a better understanding and exhilarating window onto our Universe. We look of cataclysmic events such as: supernovas – the titanic forward to an equally exciting and productive future. explosions marking the final evolutionary stage of massive stars; mergers of multi-solar-mass black-hole Many of the next generation of astroparticle physics or neutron-star binaries; and, most compelling of all, research infrastructures require substantial capital the violent birth and subsequent evolution of our infant investment and, for Europe to remain competitive Universe.
    [Show full text]
  • Light Dark Matter in a Minimal Extension with Two Additional Real Singlets
    PHYSICAL REVIEW D 103, 015010 (2021) Light dark matter in a minimal extension with two additional real singlets Markos Maniatis * Centro de Ciencias Exactas and Departamento de Ciencias Básicas, UBB, Avenida Andres Bello 720, 3780000 Chillán, Chile (Received 24 August 2020; accepted 12 December 2020; published 8 January 2021) The direct searches for heavy scalar dark matter with a mass of order 100 GeV are much more sensitive than for light dark matter of order 1 GeV. The question arises whether dark matter could be light and has escaped detection so far. We study a simple extension of the Standard Model with two additional real singlets. We show that this simple extension may provide the observed relic dark matter density, does neither disturb big bang nucleosynthesis nor the cosmic microwave background radiation observations, and fulfills the conditions of clumping behavior for different sizes of Galaxies. The potential of one Standard Model–like Higgs-boson doublet and the two singlets gives rise to a changed Higgs phenomenology, in particular, an enhanced invisible Higgs-boson decay rate is expected, detectable by missing transversal momentum searches at the ATLAS and CMS experiments at CERN. DOI: 10.1103/PhysRevD.103.015010 I. INTRODUCTION collisions. In particular, in this way a DM candidate may enhance the invisible decay rate of a SM-like Higgs boson. Recently it has been reported [1] that the NGC1052–DF2 Note that in the SM the only invisible decay channel of galaxy with a stellar mass of approximately 2 × 108 solar the Higgs boson (h) is via two electroweak Z bosons masses has a rotational movement in accordance with its which subsequently decay into pairs of neutrinos (ν), that observed mass.
    [Show full text]
  • Dark Matter Direct Detection with Edelweiss-II
    Dark matter direct detection with Edelweiss-II Eric Armengaud - CEA / IRFU Blois 2008 http://edelweiss2.in2p3.fr/ 1 Direct detection of dark matter : principles . A well-identified science goal: Detect the nuclear recoil of local WIMPs inside some material Target the electroweak interaction scale, m ~ GeV-TeV At least 3 strategies: Search for a global recoil spectrum V(Earth/Sun): Search for a - small - annual modulation V(Sun/Wimp gaz): Search for a - large - forward/backward asymetry Remove backgrounds!!! Go deep underground Use several passive shields Develop smart detectors to identify the remaining radioactivity interactions 2 Direct detection of dark matter . A well-identified science goal: Detect the nuclear recoil of local WIMPs inside some material Target the electroweak interaction scale, m ~ GeV-TeV At least 3 strategies: Search for a global recoil spectrum • Cryogenic bolometers: CDMS, CRESST, EDELWEISS… • Liquid noble elements: XENON, LUX, ZEPLIN, WARP, ArDM… • Superheated liquids: COUPP, PICASSO, SIMPLE… • Solid scintillator (DAMA, KIMS), low- threshold Ge (TEXONO), gaz detector (DRIFT)… A very active field with both R&D and large-scale setups 3 The XENON10 experiment • Quite easily scalable, « high » temperatures • First scintillation pulse (S1) + Second pulse due to e- extraction to the gaz (S2) ⇒ Nuclear recoil discrimination - especially @ low E • Position measurements ⇒ Fiducial cut (~5kg) • Low-energy threshold + Xe mass ⇒ sensitivity to low-mass Wimps Electronic recoils Nuclear recoil region But : not background-free
    [Show full text]
  • Jianglai Liu Shanghai Jiao Tong University
    Jianglai Liu Shanghai Jiao Tong University Jianglai Liu Pheno 2017 1 If DM particles have non-gravitational interaction with normal matter, can be detected in “laboratories”. DM DM Collider Search Indirect Search ？ SM SM Direct Search Pheno 2017 Jianglai Liu Pheno 2017 2 Galactic halo . The solar system is cycling the center of galaxy with on average 220 km/s speed (annual modulation in earth movement) . DM local density around us: 0.3(0.1) GeV/cm3 Astrophys. J. 756:89 Inclusion of new LAMOST survey data: 0.32(0.02), arXiv:1604.01216 Jianglai Liu Pheno 2017 3 1973: discovery of neutral current Gargamelle detector in CERN neutrino beam Dieter Haidt, CERN Courier Oct 2004: “The searches for neutral currents in previous neutrino experiments resulted in discouragingly low limits (@1968), and it was somehow commonly concluded that no weak neutral currents existed.” leptonic NC hadronic NC v beam Jianglai Liu Pheno 2017 4 Direct detection A = m2/m1 . DM: velocity ~1/1500 c, mass ~100 GeV, KE ~ 20 keV . Nuclear recoil (NR, “hadronic”): recoiling energy ~10 keV . Electron recoil (ER, “leptonic”): 10-4 suppression in energy, very difficult to detect New ideas exist, e.g. Hochberg, Zhao, and Zurek, PRL 116, 011301 Jianglai Liu Pheno 2017 5 Elastic recoil spectrum . Energy threshold mass DM . SI: coherent scattering on all nucleons (A2 Ge Xe enhancement) . Note, spin-dependent Si effect can be viewed as scattering with outer unpaired nucleon. No luxury of A2 enhancement Gaitskell, Annu. Rev. Nucl. Part. Sci. 2004 Jianglai Liu Pheno 2017 6 Neutrino “floor” Goodman & Witten Ideas do exist Phys.
    [Show full text]
  • DARWIN: Dark Matter WIMP Search with Noble Liquids
    DARWIN: dark matter WIMP search with noble liquids Laura Baudis∗† Physik Institut, University of Zurich E-mail: [email protected] DARWIN (DARk matter WImp search with Noble liquids) is an R&D and design study towards the realization of a multi-ton scale dark matter search facility in Europe, based on the liquid argon and liquid xenon time projection chamber techniques. Approved by ASPERA in late 2009, DAR- WIN brings together several European and US groups working on the existing ArDM, XENON and WARP experiments with the goal of providing a technical design report for the facility by early 2013. DARWIN will be designed to probe the spin-independent WIMP-nucleon cross sec- tion region below 10−47cm2 and to provide a high-statistics measurement of WIMP interactions in case of a positive detection in the intervening years. After a brief introduction, the DARWIN goals, components, as well as its expected physics reach will be presented. arXiv:1012.4764v1 [astro-ph.IM] 21 Dec 2010 Identification of Dark Matter 2010-IDM2010 July 26-30, 2010 Montpellier France ∗Speaker. †DARWIN Project Coordinator; on behalf of the DARWIN consortium. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ DARWIN: dark matter WIMP search with noble liquids Laura Baudis 1. Introduction One of the most exciting topics in physics today is the nature of Dark Matter in the Universe. Although indirect evidence for cold dark matter is well established, its true nature is not yet known. The most promising explanation is Weakly Interacting Massive Particles (WIMPs), for they would naturally lead to the observed abundance and they arise in many of the potential extensions of the Standard Model of particle physics.
    [Show full text]
  • First Results of the EDELWEISS-II Direct Dark Matter Search Experiment
    First results of the EDELWEISS-II Direct Dark Matter search experiment. • Dark Matter enigma • EDELWEISS-II experiment • Ge-NTD Data analysis and interpretation Silvia SCORZA Radioactive background understanding Université Claude Bernard- Institut de Physique nucléaire de Lyon WIMP search • New ID-detectors First results CEA-Saclay IRFU + IRAMIS (FRANCE), CNRS/Neel Grenoble (FRANCE), • Perspectives CNRS/IN2P3/CSNSM Orsay (FRANCE), CNRS/IN2P3/IPNL Lyon (FRANCE), CNRS-CEA/Laboratoire Souterrain de Modane (FRANCE), JINR Dubna (RUSSIA), Karlsruhe Institute of Technology (GERMANY), OXFORD University (UK) DM search motivations CDM present at all scales in the Universe… ΩB=0.044±0.004 ΩM=0.27±0.04 Ωtot=1.02±0.02 Ω =0.22±0.02 Galaxy DM Clusters Cosmology DM searches justified : direct (DM elastic scattering off target nuclei) and indirect (DM annihilation signal in galactic halo) → not enough to identify DM nature … and soon, maybe also at LHC (natural candidates arise from New Physics scenarii, such as SUSY) → no direct cosmological test (relic abundance or stability)2 WIMP dark matter (particles) WEAKLY INTERACTING MASSIVE PARTICLE Neutral and weakly interactions: neither strong nor electromagnetic → DM does not collapse to the center of the galaxy Cold enough (non-relativistic) at decoupling era Stable at cosmological scale Relic present today → explanation of Ωm 3 SUSY naturally “predicts” WIMP DM R-parity conserved → LSP stable (particle : R=+1; sparticle : R=-1) NEUTRALINO Spin-Independent Diagrams -11 -5 Interaction cross section:
    [Show full text]
  • Search for WIMP Dark Matter with the Dual Phase Liquid Argon Detector Darkside-20K
    Contribution Prospectives 2020 Search for WIMP dark matter with the dual phase liquid argon detector DarkSide-20k Principal Author: Name: Fabrice Hubaut / Pascal Pralavorio Institution: CPPM Email: [email protected] / [email protected] Phone: 04 91 82 72 51 Co-authors: (names and institutions) - Pierre Barrillon, CPPM - José Busto, CPPM - Olivier Dadoun, LPNHE - Davide Franco, APC - Claudio Giganti, LPNHE - Christian Morel, CPPM - Alessandra Tonazzo, APC Supporters: (names and institutions) people supporting the scientific/technical content of this contribution for the next decade - Yann Coadou, CPPM - Laurent Lellouch, CPT - Jaime Dawson, APC - Steve Muanza, CPPM - Cristinel Diaconu, CPPM - Emmanuel Nezri, LAM - Marie-Hélène Genest, LPSC - Thomas Patzak, APC - Marine Kuna, LPSC - Claude Vallée, CPPM - Bertrand Laforge, LPNHE - Isabelle Wingerter-Seez, LAPP - Julien Lavalle, LUPM Abstract : Dark Matter is one of the main puzzles in fundamental physics and Weakly Interacting Massive Particles (WIMP) are among the best-motivated candidates. As of today, the most sensitive experimental technique to discover WIMPs in the mass range from 2 GeV to 10 TeV is the dual phase TPC filled with ultra-pure argon or xenon. This contribution discusses the potentiality of the next generation of Liquid Argon TPC (DarkSide-20k to be run at Gran Sasso from 2023) in exploring further this mass range. The innovative design of DarkSide-20k offers a high discovery potential, both at low mass using the ionization electron signal as demonstrated by the world-leading result of DarkSide-50, and at high mass, benefiting from the intrinsic pulse shape discrimination power of scintillation signal in liquid argon to reject electronic recoils.
    [Show full text]
  • Determination of Argon and Xenon Absolute Electroluminescence Yields in Gas Proportional Scintillation Counters
    Cristina Maria Bernardes Monteiro Determination of argon and xenon absolute electroluminescence yields in Gas Proportional Scintillation Counters University of Coimbra 2010 Cristina Maria Bernardes Monteiro Determination of argon and xenon absolute electroluminescence yields in Gas Proportional Scintillation Counters Dissertation submitted to Faculdade de Ciências e Tecnologia da Universidade de Coimbra for the degree of Phylosophiae Doctor in Technological Physics Under the supervision of Prof. Dr. João Filipe Calapez de Albuquerque Veloso and co-supervision of Prof. Dr. Carlos Manuel Bolota Alexandre Correia University of Coimbra 2010 This work was supported by Fundação para a Ciência e Tecnologia and by the European Social Fund, through Programa Operacional Potencial Humano (POHP), through the grant SFRH/BD/25569/2005. To Cristiana to Quim To my parents Acknowledgements To Professor João Filipe Calapez de Albuquerque Veloso for the supervision of the present work and for all the support, suggestions and fruitful discussions along the years. To Professor Carlos Manuel Bolota Alexandre Correia for having accepted the co-supervision of the present work and for all the encouragement provided. To Professor Joaquim Marques Ferreira dos Santos for all the support, suggestions and fruitful discussions. To Hugo Natal da Luz and Carlos Oliveira for the help in data taking and processing with the CAENTM 1728b module and Radix program. To Paulo Gomes for all the informatics support throughout the years. To Fernando Amaro, who always seems to be there when we need a helping hand and, last but not least, for the friendship. To Elisabete Freitas (Beta) for the long years of friendship. To all my colleagues in the Lab, for all the support, collaboration and for the pleasant time we spent working together.
    [Show full text]
  • Dark Matter 1 25
    25. Dark matter 1 25. DARK MATTER Revised September 2015 by M. Drees (Bonn University) and G. Gerbier (Queen’s University, Canada). 25.1. Theory 25.1.1. Evidence for Dark Matter : The existence of Dark (i.e., non-luminous and non-absorbing) Matter (DM) is by now well established [1,2]. The earliest, and perhaps still most convincing, evidence for DM came from the observation that various luminous objects (stars, gas clouds, globular clusters, or entire galaxies) move faster than one would expect if they only felt the gravitational attraction of other visible objects. An important example is the measurement of galactic rotation curves. The rotational velocity v of an object on a stable Keplerian orbit with radius r around a galaxy scales like v(r) M(r)/r, where p M(r) is the mass inside the orbit. If r lies outside the visible part of the∝ galaxy and mass tracks light, one would expect v(r) 1/√r. Instead, in most galaxies one finds that v becomes approximately constant out∝ to the largest values of r where the rotation curve can be measured; in our own galaxy, v 240 km/s at the location of our solar system, with little change out to the largest observable≃ radius. This implies the existence of a dark halo, with mass density ρ(r) 1/r2, i.e., M(r) r; at some point ρ will have to fall off faster (in order to keep the∝ total mass of the galaxy∝ finite), but we do not know at what radius this will happen.
    [Show full text]
  • ZEPLIN-III Second Science Run &Beyond& Beyond
    ZEPLIN-III Second Science Run &Beyond& Beyond Henrique Araújo Imperial College London On behalf of the ZEPLIN-III Collaboration: Edinburgh University (UK), Imperial College London (UK), ITEP-Moscow (R(Ri)ussia), LIP-CiCoim bra (Pt(Portuga l) STFC Rutherford Appleton Laboratory (UK) Darkness Visible, 2-6 August 2010, IOA Cambridge Direct WIMP detection: how hard can it be? { You are looking at a snapshot of n-body simulations of the Milky Way’s DM halo (Via Lactea I) 2 The exppgerimental challenge { Low-energy particle detection is easy ;) E.g. Microcalorimetry with superconducting TES Detection of keV particles/photons with eV FWHM! { Rare event searches are also easy ;) E.g. Super-Kamiokande contains 50 kT water Cut to ~20 kT fiducial mass (self-shielding) { But doing both is hard! Small is better for signal collection Large is better for shielding background { Doh: andhd there is no trigger, and no control of luminosity… Low energy nuclear recoils { Elastic scatter off nucleus: F N o F N z Decreasing, featureless spectrum of low-energy recoils (<~100 keV) z Rate depends on target mass & spin, WIMP mass & spin, DM halo, … z Neutrons are irreducible background * { Inelastic scatter off nucleus: F N o F N o F N J z Short-lived, low-lying excited states (easier signature?) z 129Xe(3/2+ĺ1/2+) + J (40 keV), 73Ge(5/2+ĺ9/2+) + J (13 keV) z Neutrons are irreducible background * { Inelastic dark matter (iDM): F N o F N z If there is no elastic channel, then kinematic effects may ensure that “particles will scatter at DAMA but not at CDMS”
    [Show full text]
  • The Ardm -1T Experiment
    17-18 November 2008 The ArDM -1t Experiment P. Otyugova (University of Zurich), on behalf of ArDM collaboration. ETH Zurich, Switzerland: A. Badertscher, L. Kaufmann, L. Knecht, M. Laffranchi, C.Lazzaro, A. Marchionni, G. Natterer, F. Resnati, A. Rubbia (spokesperson), J. Ulbricht. Zurich University, Switzerland: C. Amsler, V. Boccone, A. Dell’Antone S. Horikawa, P.Otyugova C. Regenfus, J. Rochet. University of Granada, Spain: A. Bueno, M.C. Carmona-Benitez, J. Lozano, A. Melgarejo, S. Navas-Concha. CIEMAT, Spa in: MDM. Dan iliel, M. dPdde Prado, LRL. Romero. Soltan Institute for Nuclear Studies, Poland: P. Mijakowski, P. Przewlocki, E. Rondio. University of Sheffield, England: P.Lightfoot, K.Mavrokoridis, M. Robinson, N. Spooner. Estimated event rates for ArDM ~1 evt/ton/day ~0010.01 evt/ton/day Assumptions for simulation: For 30 keV nuclear • Cross-section normalized to nucleon recoil on Argon →σ= 10–42 cm2 =10–6 pb → MWIMP = 100 GeV • Halo Model → WIMP Density = 0.5 GeV/cm3 → vesc = 600 km/s • Interaction → Spin independent → Engel Form factor P.Ot y u gova ( U n i Z H ) ArDM WIMP Detection Principal Scattered WIMP WIMP Speed of the WIMP: 230 km/s The expected Ar recoil energies: WIMP Ar 10-100 keV. A Ar atom at rAr rest Ar atom undergoes a recoil Scintillation (light) Recoiling Light: AtArgon atom Is seen by the PMTs Charge: Extracted and detected Ionization with a good spatial (charge) resolution by a double stage LEM system. P.Ot y u gova ( U n i Z H ) The ArDM main parameters Detector Max. drift length 120 cm Target mass 850 kg Readout method Independent readout of charge& light Drift field 1÷4 kV/cm Charge readout Charge gain 500÷103 per e- Light readout Global light collection efficiency 1÷2% Background rejection is based on: 1.
    [Show full text]
  • EURECA, CRESST and EDELWEISS
    EURECA, CRESST and EDELWEISS Johannes Blümer, Karlsruhe Institute of Technology (1) The cooperation of Forschungszentrum Karlsruhe GmbH | JohannesProjektbüro Blümer KIT | 22 July 2007 and Universität Karlsruhe (TH) EURECA, CRESST and EDELWEISS Johannes Blümer, Karlsruhe Institute of Technology (1) The cooperation of Forschungszentrum Karlsruhe GmbH | JohannesProjektbüro Blümer KIT | 22 July 2007 and Universität Karlsruhe (TH) European Underground Rare Event Calorimeter Array • Started March 2005; based initially on EDELWEISS and CRESST, with additional groups joining. • Target materials: Ge, CaWO4, etc (A dependence) • Mass: above 100 kg towards 1 ton • CRESST-II and EDELWEISS-II are EURECA R&D • Aligned with Roadmap Recommendations: Multiple targets and multiple techniques The Collaboration CRESST, EDELWEISS, ROSEBUD + CERN, others United Kingdom France Oxford (H Kraus, coordinator) CEA/IRFU Saclay Germany CEA/IRAMIS Saclay MPI für Physik, Munich CNRS/Neel Grenoble Technische Universität München CNRS/CSNSM Orsay Universität Tübingen CNRS/IPNL Lyon Universität Karlsruhe CNRS/IAS Orsay Forschungszentrum Karlsruhe Spain International Zaragoza JINR Dubna Ukraine CERN Kiev Physics Aims / Requirements Probe currently most favoured cross section in the region 10−8 pb to 10−10 pb. Requires a target mass of ~ 1000 kg for few events / year. Use cryogenic detectors (scalable, mature technology). Cryogenic detectors offer excellent discrimination nuclear / electron recoil, energy resolution and large potential for further background rejection. Use
    [Show full text]