方向に感度を持つ検出器での暗黒物質探索

～ NEWAGE 　 project ～京都大学　理学研究科　助

手身内賢太朗With μ-PIC 開発グループ　

谷森達、窪　秀利竹田敦、永吉勉、

折戸玲子、植野優、高田淳史、岡田葉子

Direction Sensitive WIMP-searchwith

an Advanced Gaseous tracking Device

TALK PLAN

1. NEW ： WIMP-wind

2. AGE ： -TPC

3. NEWAGE : DM search with -TPC

4. Road to the NEWAGE2003 Oct. 16, TEA03 “New direction of particle physics”

First paper will appear in PLB.

Dark Matter : two results reported in 2003Dark Matter : two results reported in 2003

WMAP : WMAP : mmhh22=0.135=0.135+0.008+0.008

DAMA (100kg NaI) :DAMA (100kg NaI) : seven years’ observation seven years’ observation

NASA/WMAP Science Team

1. Directio1. Directionn-sensitiv-sensitivee WWIMP-searchIMP-search ::　　　　　　　　　　　　　　　　　　 　　　　　　　　　　　　　　　　　　 WIMP-WINDWIMP-WIND

- 0.009- 0.009

Other exps. say “NO” to DAMA

PLB545(2002)43

astro-ph/0307403 : DAMA’s “signal”

Investigate DAMA’s region (and deeper) Investigate DAMA’s region (and deeper) 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 with a more reliable with a more reliable methodmethod

DAMA and other exps. : DAMA and other exps. : Annual modulaitonAnnual modulaiton

Alternative method :Alternative method :

Direction Sensitive WIMP-searchDirection Sensitive WIMP-search

Newage.swf

WIMP-windWIMP-wind

Annual modulationAnnual modulation- rate difference : a few%- rate difference : a few%

“WIMP-wind”ScintillatorsScintillators

• - Tokyo

Gas detectorsGas detectors• - DRIFT （ UK ）

- NEWAGE （ Kyoto ）

2. 2. AAdvanced dvanced GGaseous tracking Devicaseous tracking Devicee : : -TPC-TPC

Preceding project : DRIFT(UK) Preceding project : DRIFT(UK) MWPC with 2mm pitchMWPC with 2mm pitch

2-D tracks only2-D tracks only

Our “AGE”: Our “AGE”: -TPC-TPC400400m pitchm pitch

3-D tracks3-D tracks

http://www.shef.ac.uk/~phys/http://www.shef.ac.uk/~phys/research/pa/DRIFT.htmlresearch/pa/DRIFT.html

1m1m

electron (~100 keV) and proton (0.8GeV) tracks detected by our -TPC

10cm10cm ~×10 sensitivities

Properties of Properties of -TPC-TPCKEY device: KEY device: -PIC-PIC- 2D gaseous imaging detector- 2D gaseous imaging detector

- Printed Circuit Board technology- Printed Circuit Board technology large area, cheap large area, cheap

- No 3D geometry- No 3D geometry mechanically-stable mechanically-stable

400μm

We are developing 30×30cm2 –PIC now.

10×10cm2

10×10cm2 –PIC works very well.

Gain map Cathode

Ano

de

VA = 560VPerformance of Performance of -PIC-PIC

Gas gain ~ 9000 @Va=600VGas gain ~ 9000 @Va=600V

gain uniformity~ 7gain uniformity~ 7No ion feedbackNo ion feedback

Test chart X-ray imageTest chart X-ray image (Xe:C (Xe:C22HH66 7:3) 7:3)

30cm

40cmμ-PICμ-PIC

encoder encoder 5 5 FPGAsFPGAsanode–cathodeanode–cathodecoincidence @ 20MHzcoincidence @ 20MHz

pre-amplifierpre-amplifierATLAS　ASDATLAS　ASD

Readout electronicsReadout electronics

READY FOR READY FOR 　　　　 SCALING UPSCALING UP

“Bragg curve”

Performance of Performance of -TPC-TPC10×10×8cm10×10×8cm33 　　 μ-TPC : developedμ-TPC : developed

Tracking including the directionTracking including the direction （（ >>3mm3mm ））Fine spatial resolution Fine spatial resolution (2D(2D ：： 120μm, 3D120μm, 3D ：： 320μm)320μm)

dE/dX [keV/cm]

χ2 /

d.o

.f

dE/dX [keV/cm]

252Cf (n+γ)

22Na (γ)

nucleus eventnucleus event

Background rejectionBackground rejectionParticle I.D.Particle I.D. (DM: nucleus BG-gamma: electron)(DM: nucleus BG-gamma: electron)　　　　　　　　　　　　 >95>95 ％ ％ gamma-ray rejection (very preliminary gamma-ray rejection (very preliminary study)study)

Experimental resultsSimulations（ 25keV F ion in 20 Torr CF

4 ）

2mmc.f. 25keV electron ：>10cm

3. 3. NEWAGE : DM search with NEWAGE : DM search with -TPC-TPCExpected WIMP-signalsExpected WIMP-signals

Recoil angle distributionRecoil angle distribution

Forward-backward asymmetryForward-backward asymmetryWIMPWIMP WIND WIND γ γ

FF

hatched ： WIMPpainted ： neutron BG

Simulation conditions:

Kamioka50 water shield-ray BG 100% rejectedCF4 20Torrtrack>3mmEth=25keV

SensitivitiesSensitivities““Detection” by Detection” by Forward/BackwardForward/Backward 3σasymmetry3σasymmetry

Simple and reliableSimple and reliable

　　 Xe for Spin-Dependent Xe for Spin-Dependent CFCF44 for Spin-Independent for Spin-Independent

　 New Journal of Phys.2(2000)14

SD

SI

4. Road to the NEWAGE 4. Road to the NEWAGE

-ray BG rejection -ray BG rejection Electron diffusion Electron diffusion Long term operationLong term operationLow pressure operationLow pressure operation

NEWAGE NEWAGE eveeve (R&D with 30cm cube) (R&D with 30cm cube)

BRAND-NEWAGEBRAND-NEWAGE　　　　　　　　　　　　 (1m(1m33×30)×30)

2003

2005+

201?

NEWAGE (1mNEWAGE (1m33) ) 1m1m33micro-TPCmicro-TPC

NEONEO

μ-PICμ-PIC

Drift planeDrift plane

micro-TPC 27mmicro-TPC 27m33

WATER 50cm

SmithSmith

SUMMARYSUMMARY

Detecting the WIMP-windDetecting the WIMP-wind by direction-by direction-sensitive methodsensitive method

Much more reliable method Much more reliable method ｔｈａｔｈａ n n annual modulationannual modulation

Now μ-TPC is at hand, so why don’t we Now μ-TPC is at hand, so why don’t we open up the NEWAGE?open up the NEWAGE?

ご支援よろしくお願いいたします。