SIGN: Potential WIMP Detection using Pressurized Nobles

J.T. White, TAMU PPC07 May 16, 2007

SIGN:Potential WIMP Detection using

Pressurized Nobles

J.T. White

Texas A&M University

5/16/07

Why Gaseous Nobles?

• Original Motivation:– Neon

• Electron mobility possible S2/S1 discrimination fiducial well defined

• Also:– Room temperature operation

• Simpler purification• No leveling• No Cryo, etc …

• NEW!!– S2/S1 Discrimination observed !

Halo Dark Matter: Starting Assumption

ρ ~ 0.3 GeV/cc <v> ~ 250 km/s@ earth

WIMP Coherent Scattering (SI)

E_recoil

20 Ascalar

A2 Dependence of Recoil Spectra

00 )(4 v

vverfEF

But, World is Radioactive!Gamma, beta

Electron recoil

U, Th, 40K, cosmogenics,etc, etc. . . .

Nuclear / Electron recoil Discrimination Very important!

S2/S1 discrimination in nobles

Gammabackground

electronrecoil

Target Nuclei

nuclear recoil

WIMP orNeutron

Scintillation

Ionization

Background Discrimination

Pressurized noble gasTest Cell

12.7 mm

Primary ScintillationS1

Prop. ScintillationS2

PTFESapphire Windows

Field Tube

Sense Wire

4-PMT - 100 atm

4-PMT Test Cell

PTFE reflector

Field tube

Sapphire Windows

TPB coating

Field Tuning

Adjust field tube potentialto optimize E-field uniformityalong sense wire

Event Waveforms (Ne-Xe example)

Neutron EventGamma Event

Areas Samei.e. ionization same

Secondary(S2)

Primary(S1)

Calibration

122 keV Gamma (+ some 136)

92 keV e-

30 keV x-ray

12.7 mm

8 mmRange 92 keV e- ~ 2 mm

Xe gas: 20 atm

Range 30 keV e- ~ 0.2 mm

Range 30 keV x-ray ~ 1 cm

Calibration

122 keV Gamma

92 keV e-

30 keV x-ray

unobserved

Calibration

122 keV Gamma

92 keV e-

30 keV x-ray

unobserved

Calibration

122 keV Gamma

92 keV e-

30 keV x-ray

Leff ~ 4.5% if Ws=76ev/phQgain ~ 1.2 p.e./e- (here)

unobserved

Neutron Scatteringw/ Mono-Energetic Neutrons

Er Ermax = (4 m M/(m+M)2) En

S – Wave

dN/dErCM frame

Edge ***

4-MeV Proton Acceleratorat TAMU

Monochromatic neutrons up to 2 MeVusing 7(Li(p,n)7Be reactions.

Tandem van de Graaff

DuoplasmatronIon sourceup to ~ 15 uA

Achieved>1 uA on target >5E6 n/sr/s

Results

Xe @ 20 atm~ 300 psi

Digression: Two-Phase Xenon Discrimination

Gammas

Neutrons

Centroid Separation ~ x 2

Recoil Energy (KeVr)

Acceptance box

See Tom Shutt’s talk tomorrow !!

TAMU Test CellAmBe Source

Xe – 20 atm Nuclear Recoil response

Er_max ~ 27 keV

gammas

neutrons

S2 Spectra

Co-57 data

Xe – 20 atm NR Q & L yields

39 keV

27 keV Assuming Wi = 21.7 ev/e-

Assuming Leff=4.5%

Xe – S2/S1 Discrimination

23.7 116

Centroid Separation > X4

21.6 107

Results

ArXe(0.5%) @ 50 atm~ 750 psi

ArXe(0.5%) – 50 atmNR Response

Er_max ~ 104 keV

~ 15 events/ton/yr @ 10-45 pb/nEr threshold 40 keVr, Mx=100 GeV

Ar Xe(0.5%) – Charge Yield

120 keV

85 keV Average overE ~ 0.6 2.5 kV/cm

Key! (Penning effect…)

ArXe(0.5%) – Light Yield

E ~ 0.6 2.5 kV/cm E ~ 0.6 2.5 kV/cm

Results

NeXe(0.5%) @ 100 atm

1600 psi

Event Waveforms (Ne-Xe example)

Neutron EventGamma Event

Areas Samei.e. ionization same

Secondary(S2)

Primary(S1)

Nuclear Recoil Discrimination: S2 vs S1

Drift regions

Higher field

S2/S1 field (and density) dependent for nuclear recoilsGammas unaffected (Emin ~ 600 v/cm here)

Lower field

Primary Pulse Shape Discrimination

S2/S1 AND Primary ShapeDiscrimination!

Primary Pulse Shape Discrimination

Gammas

Neutrons

NeXe(0.5%) – 100 atmNR Response

Er_max ~ 140 keV

Red = 140 keVrBased on S2

~ 1.8 evts/ton/yr @ 10-45 pb/n@ Er >= 40 keV Mx=100 GeV

NeXe(0.5%) – Q&L Yield

E ~ 0.6 2 kV/cmE ~ 0.6 2 kV/cm

SIGN conceptual design

• Gas• CsI Photocathode• Light gain structure using WLS fibers

Primary IonizationPrompt Scintillation

Photoelectrons

Cylinder

Detector Concept

Composite Cylinder Hub w/ WLS Fiber structure

Drift Flow

SteeringElectrodes

Gas Light Multiplier ConceptCirlex metallized plate, ~ 1mm holes

VUV synthetic silica plates

Platinum coating – VUV transmitting

VUV -> blue phosphor coating

WLS Fibers

100% e- transmissionFluorescence E/P>1Lit – 0.006 p.e./vuv pho.

100 kg 20 atm Xe Prototype

Shielding

SS Tube~0.25 inch wall WLS Fibers

FutureComposite Vessels

•Carbon, Kevlar wound•Some rated > 10000 psi !•Used on mass transit (Methane))•Used for Hydrogen fuel cells•On jets, spacecraft•DOT certified !

Shielding

10 modules 1 ton

~~4-5 m

4 m watershield

See LUX discussionIn Tom Shutt’s talk

Plans – Phased Program

• 100 kg Xe proto-experiment– Water shield– SS vessel– Only 300 psi …

• Future – Neon @ 200 atm– WIMP Mass = ????– Halo velocity dispersion = ????– Number of “species” = ????

Even a caveman could do it

SIGN: Potential WIMP Detection using Pressurized Nobles

Documents

Nobles - Slings

S uper WIMP Dark matter

WIMP Server y Aplicación Web

Pressurized and non-pressurized analyzing systems

Nobles point

Pressurized and Soft Drink Analysis non-pressurized

XENON100 Results on WIMP and non- WIMP Searches

Pressurized Tanks

4. ergonomic of wimp interface

Post-Wimp Interaction With Desktop Computersdragice.fr/papers/postwimp.pdfPost-WIMP sketching-based 3D modelling interface n MaggLite [Huot et al 2004] Post-WIMP UIMS based on ICON

Dialog Styles: Command Languages, WIMP, & Direct Manipulationstasko/6750/Talks/13-dialog-cl-wimp-dm.pdf · 1 Dialog Styles: Command Languages, WIMP, & Direct Manipulation John Stasko

Dark Matters: WIMP and Beyond

CsI crystal for WIMP Search

Seres nobles

WIMP Dark Matter in a Well-Tempered Regime - arXiv.org e ... · WIMP Dark Matter in a Well-Tempered Regime A case study on Singlet-Doublets Fermionic WIMP Shankha Banerjee(a), Shigeki

Pressurized Stairwells

Analysis of WIMP applications Instrumental Interaction

WIMP PARADIGM: CURRENT STATUShep.ps.uci.edu/~jlf/research/presentations/backup/1103fnalcolloq.pdf · THE WIMP PARADIGM • The WIMP paradigm postulates that particles that help explain

Metales nobles

From wimp and silk to smile