Noble Travails: LUX @ Sanford Labshuman/NEXT/Other_experiments/LUX_internals_006.pdfNoble Travails: LUX @ Sanford Lab Rick Gaitskell, Joint Spokesperson, LUX Collaboration Particle

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


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


• 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 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



Sensitivity Curves

17!"#$%#&''%()*+,-./

012'''*-3425%(-6. /%75216&84'*9%32%5:-8*25;

=?.==



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///


The LUX Program

22

2007-2009

LUX0.1 - CWRU

2011+

LUX - Underground

2010-2011

LUX - Surface

Right now


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


Right now: LUX at the Sanford Surface Facility

25


Title

26


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!


LUX Surface Facility @ Sanford Lab• Fully Operational Since Nov 2009 - Detector Assembly Started (Layout Same as Davis Underground Lab)•

28


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


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 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


Sanford Lab – Davis Laboratory Layout (Side View)

Rendering by J. Thomson

Control Room Clean Room

Water Tank CountingFacility

Access

Tunnel



Sensitivity Curves

39!"#$%#&''%()*+,-./

012'''*-3425%(-6. /%75216&84'*9%32%5:-8*25;

=?.==


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

Documents

Noble Travails: LUX @ Sanford Labshuman/NEXT/Other_experiments/LUX_internals_006.pdfNoble Travails: LUX @ Sanford Lab Rick Gaitskell, Joint Spokesperson, LUX Collaboration Particle