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The LZ Program Bob Jacobsen UCLA Dark Matter 2012 For the LZ Collaboration 1 Friday, February 24, 2012
The LZ Program Bob Jacobsen
UCLA Dark Matter 2012For the LZ Collaboration
1Friday, February 24, 2012
The LUX Collabora.on
Richard Gaitskell PI, ProfessorSimon Fiorucci Research AssociateMonica Pangilinan PostdocJeremy Chapman Graduate StudentCarlos Hernandez Faham Graduate StudentDavid Malling Graduate StudentJames Verbus Graduate Student
Brown
Thomas Shutt PI, ProfessorDan Akerib PI, ProfessorMike Dragowsky Research Associate ProfessorCarmen Carmona PostdocKen Clark PostdocTom Coffey PostdocKaren Gibson PostdocAdam Bradley Graduate StudentPatrick Phelps Graduate StudentChang Lee Graduate StudentKati Pech Graduate Student
Case Western
Bob Jacobsen ProfessorBill Edwards EngineerDavid Taylor EngineerMia Ihm Graduate StudentAdalyn Fyre Undergraduate Student
Lawrence Berkeley + UC Berkeley
Masahiro Morii PI, ProfessorMichal Wlasenko PostdocJohn Oliver Electronics Engineer
Harvard
Adam Bernstein PI, Leader of Adv. Detectors GroupDennis Carr Mechanical TechnicianKareem Kazkaz Staff PhysicistPeter Sorensen Postdoc
Lawrence Livermore
University of Maryland
Xinhua Bai PI, Professor, Physics Group LeaderMark Hanardt Graduate Student
Frank Wolfs PI, ProfessorWojtek Skutski Senior ScientistEryk Druszkiewicz Graduate StudentMongkol Moongweluwan Graduate Student
James White PI, ProfessorRobert Webb ProfessorRachel Mannino Graduate StudentTyana Stiegler Graduate StudentClement Sofka Graduate Student
Mani Tripathi PI, ProfessorRobert Svoboda ProfessorRichard Lander ProfessorBritt Hollbrook Senior EngineerJohn Thomson Senior MachinistMatthew Szydagis PostdocJeremy Mock Graduate StudentMelinda Sweany Graduate StudentNick Walsh Graduate StudentMichael Woods Graduate StudentSergey Uvarov Graduate Student
SD School of Mines
Texas A&M
UC Davis
Carter Hall PI, ProfessorDouglas Leonard Postdoc
Daniel McKinsey PI, ProfessorPeter Parker ProfessorJames Nikkel Research ScientistSidney Cahn Lecturer/Research ScientistAlexey Lyashenko PostdocEthan Bernard PostdocBlair Edwards PostdocLouis Kastens Graduate StudentNicole Larsen Graduate Student
Dongming Mei PI, ProfessorWengchang Xiang PostdocChao Zhang PostdocOleg Perevozchikov Postdoc
University of Rochester
U. South Dakota
Yale
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LIP CoimbraIsabel Lopes PI, ProfessorJose Pinto da Cunha Assistant ProfessorVladimir Solovov Senior ResearcherLuiz de Viveiros PostdocAlexander Lindote PostdocFrancisco Neves PostdocClaudio Silva Postdoc
UC Santa Barbara
Harry Nelson PI, ProfessorDean White EngineerSusanne Kyre Engineer
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LUX
350kg total LXe
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What’s the next step?
• More massive target: 5-6T
• Backgrounds: Stay at “<1 evt”
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LN Dewar.
Control Panel
Five thermosyphons in
this conduit
LUX
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~ 1.2 m
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PMTs -‐ R11410 MODPMT 238U
[mBq/PMT]
232Th [mBq/PMT]
40K [mBq/PMT]
60Co [mBq/PMT]
R8778 9.5±0.6 2.7±0.3 66±2 2.6±0.1
R11410 MOD
<0.4 <0.3 <8.3 2.0±0.2
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Central Active Xe PTFE Xe
Skin TiLiquid
Scintillator (IsoHexane)
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Thermosyphon dewar
Scintillator cell
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1500keV gammas into 2π Veto Efficiency Comment
No Veto 25% (Reflect from PTFE)
Liquid Scintillator Only 78% 1 cm Xe skin
Add Active Plastic Layer 92% 0.5 cm Xe skin
Active Xe Skin 98% 4 cm Xe skin
Central Active Xe PTFE Xe
Skin TiLiquid
Scintillator (IsoHexane)
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S. Fiorucci – Brown University 19
Monte-Carlo Efforts§LZ Shielding
§Muon-induced neutrons production, propagation through 12 m diameter water shield• NR event rate in LZ 20 tonne detector ~0.3 ndrur in [5 – 25 keVr], before any cuts• Fiducial, single scatter, EM component cuts, allow two more orders of magnitude rejection
§Effect of 1 m thick liquid scintillator active veto• With threshold at 100 keV, rejection of external neutrons >99.3%
§Effect of Ti and steel vessels thickness
à Safe for LZS or LZD by several OoM
§LUX internals screening and background modeling program§Extensive cataloguing of parts/materials§ Identify hot spots for similar designs§Built-in modeling tool/map for quick estimate
§Cross-check of MC parameters with theinternational community§One LUX/LZ member on advisory panel of Berkeley Cosmogenics workshop, April 2011
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Summary
LZ program toward 5-6T scale detector in Davis Cavern
Straight-forward route to higher sensitivity
Key development efforts toward control of backgrounds.
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