Opportunities in Nuclear Science at Simon Fraser University
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Undergraduate and Graduate Opportunities in Nuclear Science at Simon Fraser University Corina Andreoiu, Jean-Claude Brodovitch, Krzysztof Starosta Department of Chemistry Simon Fraser University Burnaby, BC, Canada TRIUMF Location SFU UBC TRIUMF Corina Andreoiu Simon Fraser University Arthur Erickson & Geoffrey Massey SFU (1965) has over 25,000 students and 90,000 alumni, and more than 700 tenure-track faculty Corina Andreoiu Department of Chemistry 27 research-active faculty Research Areas Analytical Inorganic & Bioinorganic Organic & Biological Physical and Nuclear Interdisciplinary Research Materials Science Chemical Biology Corina Andreoiu Department of Chemistry http://www.chemistry.sfu.ca/ Minor in Nuclear Science: Profs C. Andreoiu, K. Starosta, J.C. Brodovich . NUSC 341-3 Introduction to Radiochemistry . NUSC 342-3 Introduction to Nuclear Science . NUSC 344-3 Nucleosynthesis and Distribution of the Elements . NUSC 346-2 Radiochemistry Laboratory . NUSC 444-3 Special Topics in Nuclear Science * . CHEM 482-3 Directed Study in Advanced Topics of Chemistry * . NUSC 485-3 Particle Physics . PHYS 385-3 Quantum Physics Corina Andreoiu Student enrolment in the four courses specific to the nuclear science minor program in the last 10 years. The black bars refers to the number of graduating students enrolled in the nuclear science minor program. Corina Andreoiu Chemistry Graduate Program • Ph.D Program • M.Sc. Program • Application Process • Coursework • Tuition Fees and Financial Support Student Services • Need more information? http://www.chemistry.sfu.ca/teaching/graduates Corina Andreoiu Research Canada Foundation for Innovation British Columbia Knowledge and Development Fund Corina Andreoiu Rotations in the Universe 1030 1020 1010 100 10-10 10-20 10-20 10-10 100 1010 1020 1030 How We See Different Size Objects λ = ħ/p Corina Andreoiu Electromagnetic Radiation λ = ħ/p Corina Andreoiu Constituents of matter A ZXN A – atomic number Z – protons N – neutrons ? Corina Andreoiu Binding energy per nucleon Source: http://hyperphysics.phy-astr.gsu.edu/ Corina Andreoiu Binding Energy Energy that is released when a nucleus is assembled from neutrons and protons mp = proton mass, mn = neutron mass, m(Z,N) = mass of nucleus with Z,N • B = 0 for H, otherwise B > 0 2 D1 - deterium BE = (1.007825 + 1.008665 - 2.0141) x 931.481 MeV = 2.226 MeV 4 He2 BE = (2*1.007825 + 2*1.008665 - 4.002603) x 931.481 MeV = 28.30 MeV 238 U146 BE = (92*1.007825 + 146*1.008665 - 238.0289) x 931.481 MeV = 1822.06 MeV The more nucleons packed into a nucleus, the more energy is released, and thus the higher the binding energy. Corina Andreoiu Importance of Uranium Z = 92 Abundance 0.0054% 0.7204% 99.2742% Half-lives 2.455E5 y 7.038E8 y 4.468E9 y Uranium is a metal, common and abundant in nature, found in most rocks, soil, rivers, oceans, food; Uranium is a unique element because of its potential to generate huge amounts of energy. Eight pellets of uranium, each smaller than an average adult thumb, contain enough energy to power an average home for about one year. 1 kg of coal makes 3 kilowatt-hours of electricity. 1 kg of oil makes 4 kilowatt-hours of electricity. 1 kg of natural gas makes 6.5 kilowatt-hours of electricity. 1 kg of natural uranium makes 60,000 kilowatt-hours of electricity. Source: Canadian Nuclear Association Corina Andreoiu Nuclear Landscape (Ségre Chart) • What are the limits of nuclear existence? • Where are the drip-lines? • What is the last element we can make? • How does the nuclear force depend on varying proton/neutron ratio? • How to explain collective phenomena from the individual motion? • Tests of the Standard Model and the fundamental conservation laws proton drip line 126 Z > 110 known nuclei stable nuclei 82 50 40 protons,Z protons,Z 82 28 unknown nuclei 20 50 neutron drip line 8 28 neutrons, N 2 20 2 8 Corina Andreoiu Magic Numbers and Shell Model 184 • a nucleon moves in a common potential generated by all the other nucleons 126 82 Maria Goeppert Mayer 50 and Hans Jensen Nobel Prize Physics 1963 28 "for their discoveries 20 concerning nuclear shell structure" 8 2 M.G. Mayer, Phys. Rev. 75, 1969 (1949) Vibrations vibrations octupole prolate rotor oblate rotor http://wwwnsg.nuclear.lu.se Changes in Nuclear Structure Nuclear shell structure 126 p1/2 h f 9/2 3p 5/2 f5/2 i13/2 p3/2 As we add neutrons, traditional p1/2 N=5 p 2f h 3/2 f 9/2 shell closures are changed, and f 7/2 7/2 82 may even disappear! h 1h d 11/2 3s 3/2 This is THE challenge in trying to g7/2 h11/2 s1/2 d3/2 N=4 g predict the structure of nuclei at s 2d 7/2 1/2 d the extremes of stability towards d5/2 5/2 1g 50 the neutron drip line. g9/2 g9/2 no spin very diffuse orbit around valley surface harmonic of stability neutron drip line oscillator J. Dobaczewski et al., Phys. Rev. C 53, 2809 (1996) Corina Andreoiu Main Astrophysical Processes • How were the elements first created? • Life cycle of stars and why they shine astrophysical models require a considerable amount of nuclear information as input M.S. Smith and K.E. Rehm, Ann. Rev. Nucl. Part. Sci, 51 (2001) 91-130 Corina Andreoiu Shell Structure Affects Nucleosynthesis • Shell structure in neutron- rich nuclei affects the r-process path – this changes the predicted abundances of r-process isotopes • Need experiments to Abundance determine whether: • N=82 and 126 shells are quenched or • Astrophysical model is wrong Mass number, A K.L. Kratz et al. Ap. J. 403, 216 (1993); B. Pfeiffer et al., Z. Phys. A 357, 235 (1997) Corina Andreoiu TRIUMF Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada Canada's National Laboratory for Particle and Nuclear Physics Laboratoire national canadien pour la recherche en physique nucléaire et en physique des particules High β SCRF S 0.15 – 5.0 MeV/A C Med β Accelerated Beam SCRF L 0.15 – 1.7 MeV/A I Low β SCRF N DTL1 Thick/Hot A Target high-energy DTL2 C proton beam Ion Source RFQ Production Accelerator ISAC TRIUMF Ion 500 MeV Isotope Cyclotron Beam Separator 60 keV 100 µA Corina Andreoiu ISAC I and II @ TRIUMF Isotope Separator and Accelerator (ISAC) Accelerated radioactive beams Energy up to 4.5 MeV/A (A~150) 15 MeV/A for light nuclei Corina Andreoiu High Power Targets Corina Andreoiu Fusion-Evaporation Reactions 3-6.5 MeV/A yrast line – lowest energy for a given angular momentum Corina Andreoiu TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer TRIUMF ISAC Gamma Ray Escape Suppressed Spectrometer Detects gamma rays de-populating excited states Corina Andreoiu Associated Detection Systems Bambino Si CD (LLNL, Rochester) SHARC (York, Colorado) Bragg Detector (York) CsI(Tl) Array (Saint Mary’s) DESCANT (Guelph) DANTE (Guelph/TRIUMF) GRIFFIN (Guelph) 11 cm Corina Andreoiu Gamma-Ray Radiation and Nuclei Germanium detector γ γ γ Excitation Angular energy, keV momentum, ħ E = ħ2 I(I+1)/2I Numberof counts γ-ray energy, keV Gamma-ray energy (keV) 59 Cu 29 30 Corina Andreoiu 59Cu – A Nucleus as a laboratory GAMMASPHERE + MICROBALL experiments 58 59 60 28Si + 40Ca → 68Ge* → 59Cu + 2α + 1p 30 Zn Beam energy 146 MeV; σrel ~ 5% 57 58 59 Ex~32 MeV 29 Cu ν = 3 x 1021 rot/s 56 57 58 28 Ni 28 29 30 Extensive level scheme • 150 levels, 320 γ-ray transitions • 8 rotational bands • 5 prompt proton decays • discrete γ decay-out mechanism C. Andreoiu et al., Phys. Rev. C62, 051301(R) (2000) Eur. Phys. J A 14, 317 (2002) Corina Andreoiu TIGRESS integrated plunger (TIP) at SFU 186Pb (Z = 82; N = 104) A. Andreyev at al, 2000 N = Z shape coexistence 68Se (N = Z = 34) 72Kr (N = Z = 36) Corina Andreoiu Recoil Distance Method 40Ca Beam 36Ar v/c ~ 0.08 µm Recoil v/c ~ 0.04 For v/c ~0.04 a 1 ps (10-12 s) lifetime corresponds to 12 µm Corina Andreoiu Tigress Integrated Plunger K. Starosta Corina Andreoiu The Tigress Integrated Plunger device • implements Recoil Distance Method measurements of pico-second (10-12 s) lifetimes for gamma-ray decaying states at TIGRESS, • combines a plunger apparatus for positioning of a target and a stopper with a large (3π) solid angle CsI array of charged particle detectors for channel identification in fusion-evaporation and other reactions, • will be first used in an experiment investigating shape coexistence in 68Se and in studies of shape coexistence and evolution along the N = Z line, • has been funded in 2009 through a Research Tools and Instruments (RTI) grant by the National Sciences and Engineering Research Council of Canada (NSERC) Corina Andreoiu Delayed Gamma-Ray Spectroscopy at EMMA’s Focal Plane Techniques: recoil decay tagging technique (RDT) isomer decay tagging (IDT) Aim: delayed gamma decays depopulating isomeric states Set-up: EMMA, TIGRESS large highly-efficient Ge clover detector double-sided silicon strip detectors (DSSSDs) Topics: Study of N~Z nuclei at and beyond the proton-drip line; 100 Sn and the validity of the Z = 50 shell gap Prompt gamma The Electromagnetic Mass Analyser, EMMA The SFU Clover decay, TIGRESS DSSDs Detector The image cannot be displayed. 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