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Noble Travails:LUX @ Sanford Lab
Rick Gaitskell, Joint Spokesperson,LUX Collaboration
Particle Astrophysics Group, Brown University, Department of Physics (Supported by US DOE HEP)
http://particleastro.brown.edu
http://luxdarkmatter.org
20 years in dark matter
2
PHYSICS ITALIAN STYLE XENON10 @ Gran Sasso
CDMS II: Winter@Soudan Minnesota
New Sanford LabLUX @Homestake, South Dakota
Interaction with Ordinary Matter
Dark Matter, Sept 2007 Rick Gaitskell, Brown University, DOE
DM Direct Search Progress Over Time (2010)
~1 event kg-1 day-1
~1 event 1 tonne-1 yr-1
4
(Gross Masses kg)
ZEPLIN III.1
ZEPLIN III.2
LZ-S 1500kg
LZ 20t
CDMS Soudan 2008
LUX 350kg
XENON 100kgSuperCDMS
25 kgXMASS 800kgWARP 140kg
SuperCDMS 125 kgXENON 1000kg
!=10-48
CDMS Soudan 2009XENON Prelim 100kg
Dark Matter Searches Rick Gaitskell, Brown University, LUX / DOE
Radioactive Background Challenges• Search sensitivity (low energy region
6
How Many Gammas/Second?
>1,000 !/ second/human
Dark Matter Searches Rick Gaitskell, Brown University, LUX / DOE
Background Challenges• Search sensitivity (low energy region >99.99% rejection)
• Moving below this! Reduction in External Gammas: e.g. High Purity Water Shield 4m gives
The Importance of Depth
At the earth’s surface cosmic ray muons pass through your hand at more than 1 every second
At a depth of 4850 ft underground in Sanford Lab, the rock overburden reduces the flux of cosmic muons through your hand to around 1 per year
Dark Matter Searches Rick Gaitskell, Brown University, LUX / DOE9
Noble Liquid Dual phase Time Projection Chamber• Can measure single electrons and photons.• Charge yield reduced for nuclear recoils.• Good 3D imaging
— Eliminating edges crucial.
• Imminent Results:! XENON100 (2010, Gran Sasso Italy)! ZEPLIN III (2010, Boulby, New run)
• Construction/Running! XENON100 (Gran Sasso)! LUX 350 kg (Sanford Lab, SD)! WARP 140 (Gran Sasso)! XMASS-DM 10 kg (Kamioka)! ARDM (Canfranc)
• Single Phase is a distinct technique! XMASS 800 kg! CLEAN/DEAP 350 kg+3500 kg
Dark Matter Searches Rick Gaitskell, Brown University, LUX / DOE
• The rate of ER events in FV is determined by small angle scattering Compton events, that interact once in the FV! The rate of above events is suppressed by the tendency for
the "’s to scatter a second time. Either on the way in, or way out.
! The chance of no secondary scatter occurring is more heavily suppressed the more LXe there is• The important optimization is to maximize the amount of LXe that
lies along a line from the greatest sources of radioactivity (PMTs?) that pass through the FV.
• Example for 1.5 MeV ! from outside LXe volume! Energy Spectrum for part of energy deposited in FV! Energy spectrum for all energy in detector! Additional application of multiple scatters cut has little
additional effect on low energy event rate
• Conclusion for Event Suppression! xyz resolution of detector is important simply in defining FV.
Little additional reduction from locating vertices.! (Full xyz hit pattern does assist in bg source identification)
Topology of Gamma Events That Deposit Small Energy in FV
10
To look like DM
0 20 40 60 80 100 120
10
10
100
Recirculation Time [hours]
Elec
tron
Drif
t Len
gth
[m]
Purification vs. Time, Run009
2 error bars1 error bars
Gaitskell / LUX Collaboration
Comparison with LUX 0.1 Purity
11
• ~9 hr time constant for purification
• > 2 m electron drift length achieved(> 1000 us) with 60kg target
•Errors dominated by use of 5 cm test cell drift within large cryostat
0.2 tonnes circulation per day
XENON100 asymptoteafter 50 days
The LUX Collaboration
Richard Gaitskell PI, ProfessorSimon Fiorucci PostdocMonica Pangilinan PostdocLuiz de Viveiros Graduate StudentJeremy Chapman Graduate StudentCarlos Hernandez Faham Graduate StudentDavid Malling Graduate StudentJames Verbus Graduate Student
Brown XENON10, CDMS
Thomas Shutt PI, ProfessorDan Akerib ProfessorMike Dragowsky Research Associate ProfessorCarmen Carmona PostdocKen Clark PostdocKaren Gibson PostdocAdam Bradley Graduate StudentPatrick Phelps Graduate StudentChang Lee Graduate Student
Case Western SNO, Borexino, XENON10, CDMS
Bob Jacobsen ProfessorJim Siegrist ProfessorJoseph Rasson EngineerMia ihm Grad Student
Lawrence Berkeley + UC BerkeleySNO, KamLAND
Masahiro Morii ProfessorMichal Wlasenko Postdoc
Harvard BABAR, ATLAS
Adam Bernstein PI, Leader of Adv. Detectors GroupDennis Carr Senior EngineerKareem Kazkaz Staff PhysicistPeter Sorensen Postdoc
Lawrence Livermore XENON10
University of Maryland EXO
Xinhua Bai ProfessorMark Hanardt Undergraduate Student Frank Wolfs Professor
Udo Shroeder ProfessorWojtek Skutski Senior ScientistJan Toke Senior ScientistEryk Druszkiewicz Graduate StudentJames White Professor
Robert Webb ProfessorRachel Mannino Graduate StudentTyana Stiegler Graduate StudentClement Sofka Graduate Student
Mani Tripathi ProfessorRobert Svoboda ProfessorRichard Lander ProfessorBritt Hollbrook Senior EngineerJohn Thomson EngineerMatthew Szydagis PostdocJeremy Mock Graduate StudentMelinda Sweany Graduate StudentNick Walsh Graduate StudentMichael Woods Graduate Student
SD School of Mines
Texas A&M
UC Davis Double Chooz, CMS
ZEPLIN II
Carter Hall ProfessorDouglas Leonard Postdoc
Daniel McKinsey ProfessorJames Nikkel Research ScientistSidney Cahn Research ScientistAlexey Lyashenko PostdocEthan Bernard PostdocLouis Kastens Graduate StudentNicole Larsen Graduate Student
DongMing Mei ProfessorWengchang Xiang PostdocChao Zhang PostdocJason Spaans Graduate StudentXiaoyi Yang Graduate Student
University of Rochester
U. South Dakota
Yale
ZEPLIN II
Majorana, CLEAN-DEAP
XENON10, CLEAN-DEAP
IceCube
Collaboration meeting, Homestake, March 2010
Formed in 2007, fully funded DOE/NSF in 2008
Harry Nelson ProfessorGraduate Student
UC Santa BarbaraCDMS
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
The LUX Experiment
13
Thermosyphon
2’’ Hamamatsu R8778Photomultiplier Tubes (PMTs)
Titanium Vessels
PMT Holder Copper Plates
• 350 kg LXe detector• 122 PMTs (2’’ round)• Low-background Ti cryostat• PTFE reflector cage• Thermosyphon used for cooling (>1 kW)
Dodecagonal field cage+ PTFE reflector panels
Gaitskell - Brown University / LUX
LUX WIMP Sensitivity
14
In < 2 live days we will surpass sensitivity of all existing results for dark matter direct detection experiments
Focus on discovery ... we must design detectors with high contrast for signal ...
LUX Dark Matter Experiment
Rick Gaitskell, Brown University
LUX 350 kg / First Few Days of Operation
15
Simulated LUX data(100 kg fiducial, 100 days)
mX = 100 GeV/c2! = 5 10-45 cm2
100 kg fiducial x 4 days
2 10-44 cm2
LUX Dark Matter Experiment
Rick Gaitskell, Brown University
LUX 350 kg / Equiv to XENON100 11 day data
•LUX has 1/25th ER event rate, due to increased self-shielding•WIMP events shown are assuming cross section at current 90% CL exclusion•Since we will have ~100% acceptance for NR only really require 2 days exposure
16
Simulated LUX data(100 kg fiducial, 100 days)
mX = 100 GeV/c2! = 5 10-45 cm2
100 kg fiducial x 4 days
2 10-44 cm2
LUX Dark Matter Experiment
Rick Gaitskell, Brown University
Sensitivity Curves
17!"#$%#&''%()*+,-./
012'''*-3425%(-6. /%75216&84'*9%32%5:-8*25;
=?.==
LUX Dark Matter Experiment
Rick Gaitskell, Brown University
Summary
•The scale of the LUX detector was chosen to maximally exploit self-shielding!The mfp for Compton Scattering of gamma’s sets the scale for the exponential
suppression of external backgrounds!We are also implementing techniques that will be require for multi-tonne
detectors - Talk by Simon Fiorucci to follow• Water tank is a very scalable background shield
18
Gaitskell - Brown University / LUX 19
LUX Detector - Internals
!122 2" PMT R8778! 175 nm, QE > ~30%!U/Th ~9/3 mBq/PMT!All tested in LUX 0.1 program
!Dodecagonal field cage+ PTFE reflector panels
!Copper PMT holding plate
!HV Grids in place and tested
!"#$%&'()%*+,%'(-%./%01++2%'324
• 56772+0%'83%9:/%;?2+0@%8$>+A%B..%2K,$%L>ALMN27J%$0*OK2%P%K1+A%07*HQ%72H17,%R>0L%02HL+1K1AJ– 8M#L%B/M.%?STM!"#
• #L272%L*$%O22+%072?2+,16$%=71A72$$%>+%72,6H>+A%!"#%O*HQA716+,$• #L2%K2N2K%1U%7*,>1*HIN>0J%*K72*,J%*HL>2N2,%>+%0L2$2%!"#$%R16K,%O2%*+%*HH2=0*OK2%O*$2K>+2%U17%0L2%'()%*+,%'(-%2?2+0$
– -2?1+$07*02,%V;@%*N27*A2W99XY%?*0$%U*H017%9%O2[27%=L2MQ2\%72$=1+$2%>+%'83%0L*+%>+%3;]^]B//
R8778
SEE FIORUCCI TALK THIS AFTERNOON
!"#$%&'()%*+,%'(-%./%01++2%'324
• 8+,27%'(%)_%,2N2K1=?2+0%=71A7*?@%-8);'%D`-– '*7A27%,>*?2027%P%0R>H2%H1KK2HI1+%*72*a%D*,>1*HIN>0J%U670L27%72,6H2,a– b+%.//Z%>+>I*KKJ%U*O%1U%*+,%02$02,%G*?*?*0$6%9C%DBB/c:%>+%'32
• #2$02,%V;M'32%1=27*I1+%P%*KK%!"#$%=27U17?2,%>,2+IH*KKJ%01%0L1$2%1U%$*?2%*$%DEFFE• d2KK%6+,27$011,%=27U17?*+H2a%)0*OK2%=27U17?*+H2a• G>AL%A*>+$%e:I1+*K%*?=K>g27$%72T6>72,a%;K2H071+>H$%R>0L>+%H7J1$0*0%*72%K>?>02,%
01%=*$$>N2%H1?=1+2+0$%R>0L%N27J%K1RMR2KK%6+,27$011,%7*,>1*HIN2%O*HQA716+,$
– -2N2K1=2,%+2R%6K07*%K1R%O*HQA716+,%9C%!"#$%U17%'32@%DBB_B/?1,• S*HQA716+,%?2*$672,%8M#L%hBMB%?STM!"#%&Z/X%5'4%P%]1%8M#L%$>A+*K%$22+• #L>$%H1?U170*OKJ%272?2+0$%U17%'(-%,202H017• 8=A7*,2,%G*?*?*0$6%)6=27%O>*KQ*K>%=L101H*0L1,2$%R>KK%*K$1%O2%*N*>K*OK2%01%?1N2%V;%*O1N2%_/X
• D2T6>72?2+0%>$%U17%B///
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
The LUX Program
22
2007-2009
LUX0.1 - CWRU
2011+
LUX - Underground
2010-2011
LUX - Surface
Right now
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
Present: LUX at the Sanford Surface Facility
23
The dress rehearsal • Full-scale LUX assembly and deployment
• Duplicate of the underground layout• Smaller water tank (3 m)• Cleanroom class 1,000 (will be relocated underground)
• LUX operations since November 2009
Bottom-up viewBottom-up view
LUX Collaboration Drawings: James White, TAMU; Animation: Carlos Faham, Brown University , v1.1
LUX Detector Assembly Animation v1.1
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
Right now: LUX at the Sanford Surface Facility
25
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
Title
26
Gaitskell - Brown University / LUX 27
Sanford Lab @ Homestake
Davis Cavern 4300 m.w.e " 4 µ/m2/d
Surface Facility
!Funded with 70 M$ private donation+ 39 M$ from state of SD
!Demonstrator for DUSEL, but already competitive!
Dark Matter Searches Rick Gaitskell, Brown University, LUX / DOE
LUX Surface Facility @ Sanford Lab• Fully Operational Since Nov 2009 - Detector Assembly Started (Layout Same as Davis Underground Lab)•
28
Gaitskell - Brown University / LUX 29
Sanford Lab – LUX Surface Facility
!Full-scale test of LUXassembly and deployment! 350 kg Xe! 122 PMTs! Titanium cryostat! Full DAQ system
!Refurb supported entirely by SDSTA funds
!Exact duplicate of the underground layout for all major systems! Smaller d=3m water tank, permits data taking with manageable background (Brown MC)! CL 1k clean room, will be relocated underground
See larger version next slide
Hunting for WIMPS in the Black Hills Carlos Hernandez Faham, Brown University APJC, Sep 29, 2010
Title
30
LUX Experiment / Rick Gaitskell / Brown University
1964 / 2009 “They want to fill the cavern with what ?*?”
Davis Cavern
34
1964
LUX Experiment / Rick Gaitskell / Brown University 35
LUX Experiment / Rick Gaitskell / Brown University 36
LUX 1.0 – Davis Laboratory (4850L)
!Construction/excavation completed!Shared access with Majorana facility,
!Two storey, dedicated LUX 55’ x 30’ x 32’ facility, CL 100k!Includes CL 1k clean room, control room, counting facility
1964
Rendering by J. Thomson
Lab
Mine shaft
Majorana
LUX
Mechanical& Electrical Services
200 m
LUX Experiment / Rick Gaitskell / Brown University 37
Gaitskell - Brown University / LUX 38
Sanford Lab – Davis Laboratory Layout (Side View)
Rendering by J. Thomson
Control Room Clean Room
Water Tank CountingFacility
Access
Tunnel
LUX Dark Matter Experiment
Rick Gaitskell, Brown University
Sensitivity Curves
39!"#$%#&''%()*+,-./
012'''*-3425%(-6. /%75216&84'*9%32%5:-8*25;
=?.==
LUX Experiment / Rick Gaitskell / Brown University 40
Future LUX-ZEPLIN III (LZ) Program
!New collaborators from Zeplin III and US institutions! Imperial College, London! STFC Rutherford Appleton Lab! ITEP, Moscow!Moscow Engineering Physics Institute
!Several phases: 3 tonne at Sanford Lab, SUSEL, 2012->and 20 tonne at DUSEL from 2014 " 2018+
!DUSEL Program at Homestake 4850L and 7400L
LZ20baseline design
LUX
2 m
! LIP, Coimbra!University of Edimburgh!UC Santa Barbara! LBNL