the lz program - university of california, los angelesrobert webb professor rachel mannino graduate...

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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7Friday, February 24, 2012

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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