Elena Aprile 1

SAGENAP Review of the XENON Project March 12-13, 2002

The XENON Project

A 1 tonne Liquid Xenon experiment for a sensitive Dark Matter Search

Elena Aprile

Physics Department, Columbia University

Elena Aprile 2

SAGENAP Review of the XENON Project March 12-13, 2002

The XENON Project Overview

Outline

Science Motivation and Goals Overview Dark Matter Direct Searches Worldwide LXe Properties relevant to WIMP Detection XENON Instrument Design Overview Comparison with other LXe Projects XENON Team Presentations XENON Organization and Management

Elena Aprile 3

The XENON Collaboration

Columbia University: E. Aprile (Principal Investigator)

T. Baltz, A. Curioni, K-L. Giboni, C. Hailey, L. Hui, M. Kobayashi and K. Ni

Brown University: R. Gaitskell

Princeton University: T.Shutt

Rice University: U. Oberlack

LLNL: W. Craig

Elena Aprile 4

Why should NSF support XENON

• Because a WIMP experiment with discovery potential will have enormous scientific impact in particle physics and astrophysics. Need to validate discovery with different targets and technology.

• Because the timing is right and the proposed XENON concept is based on a relatively simple technology with unique suitability for the 1-tonne scale required by the science.

• Because the proposing team combines extensive experience with large scale LXe detectors with complementary experience in other key areas required for a successful realization of the XENON dark matter project!

Elena Aprile 5

The Case for Non-Baryonic Dark Matter

• Standard BBN calculations + 4He and D primordial abundance

Ωbh2 = 0.020 ± 0.001(APJ, 552, L1, 2001)

• Measurements of the matter density

Ωm = 0.2 ~ 0.4h=H0/100 kms -1Mpc-1 (h = 0.6 ~ 0.8)

• Cluster velocity dispersion (Mass to Light ratio)• Galactic rotation curves• Cluster baryon fraction from X-ray gas• CMB anisotropies give Ωmh2 = 0.15 ± 0.05 (APJ, 549, 669, 2001)

and also confirms Ωbh2 ~ 0.02

ΩΩmm >> Ω >> Ωbb

Elena Aprile 6

Non-baryonic Dark Matter Candidates

Neutrinos: hard to make up a significant fraction of mass density with neutrinos, unless much more massive than observed

m < 0.1 eV ( PRL 81(1998)1562)

Axions: strong CP, m ~ 10-5eV, search is in progress using microwave cavities ( PRL 80(1998)2043)

Massive Compact Halo Objects (MACHO): with 10-7 - 10 Mo

cannot account for a large fraction of the DM in the Milky Way halo

(ApJ 550(2001)L169)

Weakly Interacting Massive Particles (WIMPS):Stable (or long lived) particles left over from the BB, decoupling when non-

relativistic: their relic density ΩXh2 ~ 1/<X v>

(X ~ weak) ΩXh2 ~ 1

Elena Aprile 7

Supersymmetry

• Stabilizes MPL and MZ hierarchy

• Unification of coupling constants

• Lightest Super Particle is stable

• Neutralino 02

01

~~~~

• SUSY particles were not invented to solve the dark matter problem.• Particles with several 100 GeV/c2 actively being pursued at accelerators. • Direct WIMP searches can probe mass values impossible to reach at colliders.• Typical WIMP nucleon cross sections in the range 10-5 and 10-11 pb

Superposition of photino, zino and higgsinos

SUSY offers the favorite WIMP candidate

Elena Aprile 8

Muon g-2 Measurement

• BNL results on muon anomalous magnetic moment disagree with Standard Model at 1.6 level (PRL 86(2001)2227)

• If discrepancy is due to SUSY, a large neutralino-nucleon cross section (10-9 pb) and a low mass (<500 GeV) are favored

• World eagerly awaiting for new results from last run!

Elena Aprile 9

WIMP Direct Detection

• Elastic scattering off nuclei in

laboratory target

measure nuclear recoil energy

• Spin-independent interactions are coherent ( A2) at low energy dominate for most models. Target with odd isotopes needed for spin-dependent interactions

• Energy spectrum and rate depend on local dark matter density 0 :

measured galactic rotation curve : flat out to 50 kpc with vcir220 km/s spherical halo with 0 0.3-0.5 GeV/cm3 and M-B velocity distribution with v 220 km/s

Elena Aprile 10

Experimental Challenges

With E0 = 1/2MX(0c)2

r = 4 MX MA /(MX+ MA )2

R0 = T0c0

c10.78 and c20.58

F=form factor (see Phys.Rept.267(1996)195

With E0 = 1/2MX(0c)2

r = 4 MX MA /(MX+ MA )2

R0 = T0c0

c10.78 and c20.58

F=form factor (see Phys.Rept.267(1996)195

)()( 2/

0

01

02R

EEc

rR

EFeE

Rc

dE

dRrR

• Recoil energy is small few keV detectors with low threshold

• Event rates are low << radioactive background

detectors with low radioactivity, deep underground and with active background rejection

Elena Aprile 11

Background Rejection Methods

• Reject events more likely to be due to , e, radioactivities

multiple-scatters (WIMPs interact too weakly) HDMS

single-scatters localized near detector walls (WIMPs interact anywhere) CDMS ZIP detectors

electron recoils (WIMPs more likely interact with nucleus)

CDMS, EDELWEISS (CRESST, ZEPLINs, DRIFT)

A 3D LXeTPC like XENON will combine all these rejection capabilities

• Use motion of Earth/Sun through WIMP halo

direction of recoil DRIFT

annual modulation DAMA, NAIAD

Elena Aprile 12

Expected rates for various targets

For a heavy target nucleus such as Xe, a very low recoil energy threshold is crucial.

The expected rate, integrated above threshold of ~16 keV is 1 events/ kg/day

Elena Aprile 13

WIMP Direct Searches with Recoil Discrimination

Project Detectors Active Mass Rejection Method Location( mwe) Timescale

CDMS II CryoArray

Si and Ge 2 kg (Si) +5 kg (Ge) 1 tonne

Phonon and Charge Soudan (2200) 2002 – 2007 Start 2006 ?

EDELWEISS I EDELWEISS II

Ge 3 X 320 g ~ 1 kg 21 X 320 g ~ 7 kg

Phonon and Charge Frejus (4600) 2002 - 2004 Start 2004 ?

CRESST II CaWO4 33 X 300 g ~10 kg Phonon and Scintillation

Gran Sasso (3800) 300 g setup 2002

ZEPLIN II ZEPLIN IV

LXe 30 kg 1 tonne

Charge and scintillation Boulby (3300) Construction 2001 Start 2007 ?

ZEPLIN III ZEPLIN-MAX

LXe 6 kg 1 tonne

Charge and scintillation Boulby (3300) Construction 2001 Start 2006 ?

XMASS LXe 1 kg 20kg

Charge and scintillation Kamioka (2600) Installed 2001 Construction 2002

XENON

LXe 10 kg 100 kg 1 tonne

Charge and scintillation Homestake (>4000) Operational 2004 Start 2005 ? Start 2007 ?

DRIFT 1 , 2 DRIFT 3

CS2 < 1 kg 100kg

Recoil direction Boulby (3300) Installed 2001 Start 2004 ?

Elena Aprile 14

Current and Projected Limits of Spin-Independent WIMP Searches

• Projection for CDMS Soudan (7kg Ge+Si) and competing experiments in Europe, including LXe projects of the UKDM program is ~1 event / kg / yr

• It will take a target mass at 1 tonne scale and similar background discrimination power to reach a sensitivity of ~1 event / 100kg / yr or ~ 10-46 cm2

• LXe attractive target for scale-up. Projection for XENON based on Homestake, 99.5% recoil discrimination, 16 keV true recoil energy threshold and an overall 3.9x 10-5 cts /kg /d /keV background rate.

Elena Aprile 15

Why is Liquid Xenon Attractive for Dark Matter High mass Xe nucleus good for scalar interaction of WIMPs

High atomic number (Z=54) and density (r=3g/cc) good for compact and flexible detector geometry. “Easy” cryogenics at –100C

High ionization (W=15.6eV) yield and small Fano factor for good E/E

High electron drift velocity (v=2 mm/s) and low diffusion for excellent spatial resolution. Calorimetry and 3D event localization powerful for background rejection based on fiducial volume cuts and event multiplicity

High scintillation (W~13 eV) yield with fast response and strong dependence on ionizing particle for event trigger and background discrimination with PSD

Distinct charge/light ratio for electron/nuclear energy deposits for high background discrimination

Available in large quantity and “easy” to purify with a variety of methods. Demonstrated electron lifetime before trapping of order 1 millisecond for long drift. No long-lived radioactive isotopes. 85Kr contamination reducible to ppb level

Elena Aprile 16

… and for Solar and 0Decay

124Xe (0.10%)

126Xe (0.09%)

128Xe (1.92%)

129Xe (26.4%)

130Xe (4.07%)

131Xe (21.2%)

132Xe (26.9%)

134Xe (10.4%)

136Xe (8.87%)

Mostly Odd Mostly Even

-nucleus Separation here

Odd enriched Solar neutrino Dark matter Spin dependent

Even enriched:containing 136Xe 2/0 Dark matter Spin independent

XXMMAASSSS

LXe prototype in Kamioka

EEXXOO

LXe prototype at Stanford

Elena Aprile 17

Ionization and Scintillation in Liquid Xenon

I/S (electron) >> I/S (non relativistic particle)

Alpha scintillation

electron scintillation

Electron charge

Alpha charge

Electric Field (kV/cm)

L/L

0 or

Q/Q

0 (%

)

Elena Aprile 18

Electron vs Nuclear Recoil Discrimination(Direct & Proportional Scintillation )

Dri

ft T

ime

E

anode

e-

grid

cathode

~1μ

s~4

0 ns

Nuclear recoil from•WIMP •NeutronElectron recoil from•gamma•Electron•Alpha

Gas

Liquid

Measure both direct scintillation(S1) and charge(proportional scintillation) (S2)

Proportional scintillation depends on type of recoil and applied electric field.

electron recoil → S2 >> S1nuclear recoil → S2 < S1 but detectable if E large

Dual Phase Detection Principle Common to All LXe DM Projects

Elena Aprile 19

The XENON Experiment : Design Overview

• The XENON design is modular.An array of 10 independent 3D position sensitive LXeTPC modules, each with a 100 kg active Xe mass, is used to make the 1-tonne scale experiment.

• The fiducial LXe volume of each module is self-shielded by additional LXe. The thickness of the active shield will be optimized for effective charged and neutral background rejection.

• One common vessel of ~ 60 cm diameter and 60 cm height is used to house the TPC teflon and copper rings structure filled with the 100 kg Xe target and the shield LXe (~50 kg ).

Elena Aprile 20

The XENON TPC: Principle of Operation

• 30 cm drift gap to maximize active target long electron lifetime in LXe demonstrated

• 5 kV/cm drift field to detect small charge from nuclear recoils internal HV multiplier (Cockroft Walton type)

• Electrons extraction into gas phase to detect charge via proportional scintillation (~1000 UV /e/cm) demonstrated

• Internal CsI photocathode with QE~31% (Aprile et al. NIMA 338,1994) to enhance direct light signal and thus lower threshold demonstrated

• PMTs readout inside the TPC for direct and secondary light need PMTs with low activity from U/Th/K

Elena Aprile 21

The XENON TPC Signals

• Three distinct signals associated with typical event. Amplification of primary scintillation light with CsI photocathode important for low threshold and for triggering.

• Event depth of interaction (Z) from timing and XY-location from center of gravity of secondary light signals on PMTs array.

• Effective background rejection direct consequence of 3D event localization (TPC)

Elena Aprile 22

Detection of LXe Light with a CsI Photocathode

• Stable performance of reflective CsI photocathodes with high QE of 31% in LXe has been demonstrated by the Columbia measurements

• CsI photocathodes can be made

in any size/shape with uniform response, and are inexpensive.

• LXe negative electron affinity Vo(LXe)= - 0.67 eV and the applied electric field explain the favorable electron extraction at the CsI-liquid interface. Aprile et al. NIMA 338(1994)

Aprile et al. NIMA 343(1994)

Elena Aprile 23

Assumptions

Wph : 13 eV

ph: 1.7 m

Quenching Factor: 25% Q.E. of PMTs: 26% Q.E. of CsI : 31% R.E of Teflon Wall: 90% Mass of Liquid Xe: 100 kg 37 PMTs (2 inch) array

Light Collection Efficiency: MonteCarlo

Elena Aprile 24

Simulation Results

• A 16 keV (true) nuclear recoil gives ~ 24 photoelectrons. The CsI readout contributes the largest fraction of them.

• Multiplication in the gas phase gives a strong secondary scintillation pulse for triggering on 2-3 PMTs.

• Coincidence of direct PMTs sum signal and amplified light signal from CsI

• Main Trigger is the last signal in time sequence post-triggered digitizer read out Trigger threshold can be set very low because of low event rate and small number of signals to digitize. PMTs at low temperature low noise.

• Even w/o CsI (replaced by reflector) we still expect ~6 pe . Several possible ways to improve light collection.

Elena Aprile 25

Summary of Previous Nuclear Recoil Measurements (Quenching Factor)

0 10 20 30 40 50 60 70 80 900

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Recoil Energy (keV)

Rel

ativ

e S

cint

illat

ion

Eff

icie

ncy

x=Bernabeio,+ = UKDMC-- = Lindhard theory

previous measurements have wide scatter

no measurements at all at low energies

results consistent with Lindhard theory

Elena Aprile 26

We have experience measuring neutron-nuclear recoil efficiency

typical setup for measurement ofnuclear recoil scintillation efficiencyat University of Sheffield

measured low energy nuclear recoil efficiency of liquid scintillator

Hong, Hailey et. al., J. AstroParticle Physics 20012.9 MeV neutron beam

Elena Aprile 27

Why Do Nuclear Recoil Scintillation Efficiency Measurements?

• Confirm that measured efficiency at higher energies extends down to lowest energies of interest to a WIMP search

• Confirm result in our particular experimental configuration. Results can vary with Xe purity, light collection efficiency etc.

• Measure true nuclear recoil scintillation pulse shapes

Elena Aprile 28

Charge readout with GEMs: a promising alternative

• High gain in pure Xe with 3GEMs demonstrated

• Coating of GEMs with CsI

• 2D readout for mm resolution

See Bondar et al.,Vienna01

Elena Aprile 29

XENON Technical Heritage: LXeGRIT

A 30 kg Liquid Xenon Time Projection Chamber developed with NASA support. 3D imaging detector with good spectroscopy is the basis of the balloon-borne LXeGRIT, a novel Compton Telescope for MeV Gamma- Ray Astrophysics. The LXeTPC operation and response to gamma-rays successfully tested in the lab and in the harsh conditions of a near space environment. Road to LXeGRIT: extensive R&D to study LXe ionization and scintillation properties, purification techniques to achieve long electron drift for large volume application, energy resolution and 3D imaging resolution studies, electron mobility etc.

Elena Aprile 30

A Liquid Xenon Time Projection Chamber for Gamma-Ray Astrophysics

Elena Aprile 31

The Columbia 10 liter LXeTPC

• 30 kg active Xe mass• 20 x 20 cm2 active area• 8 cm drift with 4 kV/cm• Charge and Light readout• 128 wires/anodes digitizers• 4UV PMTs

Elena Aprile 32

High Purity Xenon for Long Electron Drift and Energy Resolution

And the power of Compton Imaging

Elena Aprile 33

Compton Imaging of MeV -ray Sources

Elena Aprile 34

3D capability for event discrimination: Flight Data

Elena Aprile 35

From the Lab to the Sky: The Balloon-Borne Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)

Compton Imaging EventsAtm/Cosmic Diffuse MC simulation and Data

Elena Aprile 36

Background Considerations for XENON

and induced background85Kr (1/2=10.7y): 85Kr/Kr 2 x 10-11 in air giving ~1Bq/m3

Standard Xe gas contains ~ 10ppm of Kr10 Hz from 85Kr decays in 1 liter of LXe.Allowing <1 85Kr decay/day i n XENON energy band <1 ppb level of Kr in Xe

136Xe 2 decay (1/2=8 x 1021y): with Q= 2.48 MeV expected rate inXENON is 1 x 10-6 cts/kg/d/keV before any rejection

• Neutron induced backgroundMuon induced neutrons: spallation of 136Xe and 134Xe take 10 mb and

Homestake 4.4 kmwe estimate 6 x 10-5 cts/kg/d before any rejection reduce by muon veto with 99% efficiency

(,n) neutrons from rock: 1000/n/m2/d from (,n) reactions from U/Th of rock appropriate shield reduces this background to 1 x 10-6 cts/kg/d/keV

Neutrons from U/Th of detector materials: within shield, neutrons from U/Th ofdetector components and vessel give 5 x 10-5 cts/kg/d/keV lower it by x10 with materials selection

Elena Aprile 37

Background Considerations for XENON

-rays from U/Th/K contamination in PMTs and detector components dominate the background rate. For the PMTs contribution we have assumed a low activity version of the Hamamatsu R6041 ( 100 cts/d ) consistent with recent measurements in Japan with a Hamamatsu R7281Q developed for the XMASS group (Moriyama et al., Xenon01 Workshop).

Numbers are based on Homestake location and reflect 99.5% background rejection but no reduction due to 3D imaging and active LXe shield.

Elena Aprile 38

How is XENON different from other Liquid Xe Projects?

Elena Aprile 39

UCLA ZEPLIN II

Elena Aprile 40

ZEPLIN II

Elena Aprile 41

ZEPLIN II ZEPLIN IV

The latest design as at DM2002

The latest design as at DM2002

30 kg 1000 kg

Elena Aprile 42

UKDM ZEPLIN III

Elena Aprile 43

ZEPLIN III

Elena Aprile 44

The LXe Program at Boulby

Elena Aprile 45

The LXe Program at Kamioka

Liq. Xe(1kg)9.5 cm Drift

Wire set(Grid1,AnodeGrid2)

PTFE Teflon(Reflector)

MgF2 Windowwith Ni mesh(cathode)

OFHC vessel(5cm)

gas filling line

Cold finger

PMT

Gas Xe

with 99% rejection

with new PMTs no rejec.

present

XMASS

Elena Aprile 46

direct proportionaldirect

proportional

direct

drift timedrift time

42000photon/MeVDecay time 45nsec

Signals from 1kg XMASS Prototype

Elena Aprile 47

XMASS Recoil /γ ray Separation

>99% γ ray rejection>99% γ ray rejection

22 keV gamma ray

Recoil Xenon (neutron source)

Direct scintillation(S1)

Pro

por

tion

al s

cin

till

atio

n(S

2)

(Ref. JPS vol.53,No 3,1998, S.Suzuki)

Elena Aprile 48

XMASS: low activity PMT development

p.e.

coun

ts

p.e.

coun

ts

57 Co (122keV)

137Cs 662keV

σ/E = 15 %2.4 [p.e./keV] at 250[V/cm]

with R7281MgF2 (Q.E.30%) (HAMAMATSU(prototype)A low activity version of this tube shows ~4.5× 10-3 Bq!

Towards a 20 kg Detector

Elena Aprile 49

Answer to Question

• LXe long recognized as promising WIMP target for a large scale experiment with relatively simple technology. So far however development effort has been subcritical.

• Low energy threshold and background rejection capability yet to be fully demonstrated.

• Recent move to an underground lab - 1 kg XMASS detector in Kamioka- an important milestone. Scale up to a 20 kg detector of same design (7 PMTs vs 1) started.

• UCLA ZEPLIN II is similar in size and design to XMASS: drift in LXe over ~ 10 cm with low electric. Secondary light pulse from low energy nuclear recoils hard to detect. Scale up to 1 tonne with a monolithic detector (ZEPLIN IV) too risky and unpractical.

• UKDM ZEPLIN III better discrimination power and lower threshold due to high electric field. Design does not present an easy scale up from 6 kg to sizable modules of order 100 kg.

• XENON combines the best of the techniques with a design which can be easily scaled. Strength of experience with a 30 kg LXeTPC for gamma ray astrophysics + critical mass at Columbia with collaborators key experiences in DM searches.

Elena Aprile 50

XENON Phase 1 Study: 10 kg Chamber

• Demonstrate electron drift over 30 cm (Columbia)

• Measure nuclear recoil efficiency in LXe (Columbia)

• Demonstrate HV multiplier design (Columbia)

• Measure gain in Xe with multi GEMs (Rice and Princeton)

• Test alternative to PMTs, i.e. LAAPDs (Brown)

• Selection and test of detector materials (LLNL)

• Monte Carlo simulations for detector design and background studies (Columbia /Princeton/Brown)

• Study Kr removal techniques (Princeton)

• Characterize 10 kg detector response and with and neutron sources (Entire Collaboration)

Elena Aprile 51

What next? XENON and NUSL

• The result of the 2yr Phase 1 will be a working 10 kg prototype with demonstrated low ER threshold and recoil discrimination capability. Its move to a deep underground location will initiate science return.

• Phase 2 is for construction and operation of a 100 kg module as 1st step towards 1 tonne. We plan to seek DOE and NSF support and more collaborators

• By this time the situation of a NUSL will be clear. If NUSL is delayed, several alternative locations possible ( Boulby, GS, WIPP, etc.)…but deeper the better..

101

102

103

104

105

106

Mu

on

In

ten

sity

, m-2

y-1

5 6 7 8 9

1032 3 4 5 6 7 8 9

104

Depth, meters water equivalent

Soudan

Kamioka

Gran Sasso

Homestake (Chlorine)

BaksanMont Blanc

Sudbury

WIPP

Muon flux vs overburden

NUSL - Homestake

Proposed NUSL Homestake Current Laboratories

Elena Aprile 52

Summary

• Liquid Xenon is an excellent detector material well suited for the large target mass required for a sensitive Dark Matter experiment.

• The XENON experiment is proposed as an array of ten independent, self shielded, 3D position sensitive LXeTPCs each with 100 kg active mass.

• The detector design, largely based on established technology and >10 yrs experience with LXe detectors development at Columbia, maximizes the fiducial volume and the signal information useful to distinguish the rare WIMP events from the large background.

• With a total mass of 1-tonne, a nuclear recoil discrimination > 99.5% and

a threshold of ~ 16 keV, XENON expected sensitivity of 0.0001 events/kg/day in 3 yrs operation, will cover most SUSY predictions.

Elena Aprile 53

XENON Organization

Subsystem responsibility is allocated amongst the team of experienced co-investigators.

Elena Aprile 54

XENON Management Approach

• Phase I of the XENON project spans a 2 year period from the funding start date. This instrument development effort has the focused goal of a clear demonstration of the capabilities of a 10 kg LXe detector for a sensitive Dark Matter search.

• The 10 kg prototype defines the roadmap to the Phase II development of a 100 kg detector as one unit of a 1 tonne scale XENON experiment.

• In complexity, the XENON Phase I development does not exceed the NASA funded LXeGRIT experiment and we adopt the successful practices developed during this project.

• We have the required critical mass with extensive expertise in LXe detector technology and other areas relevant to a Dark Matter experiment. This, plus sensible management practices will insure meeting the milestones promised by the end of the 2nd year of Phase I.

Elena Aprile 55

Management Activities

To coordinate the efforts and insure the appropriate level of communication and exchange of information between the Columbia team and team members at Brown, Princeton, Rice, and LLNL the PI will:

– organize bi-weekly videoconference meetings – obtain monthly progress reports on all sub systems – organize semi annual project reviews with participation of

collaborators and external advisors – prepare yearly progress reports for NSF – encourage student/minority involvement in the research – take full responsibility for the key deliverables to NSF by end of

Phase I

Elena Aprile 56

Development Schedule

Year 1 activities concentrate on:

• Monte Carlo simulations to guide the design

• Gas system construction and testing

• Neutron recoil efficiency measurements

• Baseline detector development• Alternative detector development• Materials selection and testing

Elena Aprile 57

Development Schedule (2)

Year 2 activities concentrate on:

• Build of the 10kg prototype• Demonstration of Krypton

reduction• Design of the 100kg instrument

End of Phase I results in near final design of 100kg module and demonstration of all key technologies in the 10 kg prototype.

Elena Aprile 58

Team Members Expertise

Name Institution Main Expertise Other Experiments

Elena Aprile Columbia Liquid rare gas detectors Ionization and scintillation Time projection chambers

Imaging detectors

LXeGRIT XENA

Chuck Hailey Columbia X-ray Proportional scintillation counters

Scintillators Hard X-ray focusing optics

HEFT ZEPELIN III

Karl Giboni Columbia Imaging detectors Time Projection Chambers

Room temp. semiconductors Analog and Digital Electronics

LXeGRIT XENA

Masanori Kobayasi Columbia Germanium Detectors LXe Time Projection Chamber Imaging detectors data analysis

SELENE LXeGRIT

Uwe Oberlack Rice

(formerly Columbia)

Data acquisition Imaging detectors data analysis

Event reconstruction techniques LXe Time Projection Chamber

COMPTEL LXeGRIT

Tom Shutt Princeton

Low noise electronics Cryogenic detectors

Low radioactivity materials Monte Carlo background studies

CDMS Borexino

William Craig LLNL (formerly Columbia)

Project management System engineering

Instrument development

DRIFT HEFT

Richard Gaitskell

Brown Cryogenic detectors Low noise electronics

Monte Carlo background studies

CDMS CryoArray

Elena Aprile 59

Budget Details

16%

24%

23%

2%

28%

7%

Senior Personnel

Other Labor

M&S

Travel

Subcontracts

Indirect

Budget breakout (of 2 year total) is consistent with our fast track development of a working prototype

Year 1 request 823k$ Year 2 request 873k$

Elena Aprile 60

Team Members Presentations

Elena Aprile 61

Materials Selection and Testing

• Candidate material selection will begin with study of existing databases assembled for other projects.

• LLNL personnel (Craig, Ziock) are associated with ongoing projects requiring low background and will use this existing infrastructure to do testing of candidate materials.

• Close coupling between this effort and the XENON 10/100 kg design team to ensure optimal material choices are incorporated as quickly as possible.

Bill Craig (LLNL)