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Direction-Sensitive Dark Matter Search --NEWAGE--. ( Ne w generation W IMP search with an a dvanced g aseous tracker e xperiment). with H. Nishimura, T. Tanimori, H. Kubo, K. Hattori, C. Ida, S. Iwaki, S. Kabuki, A. Takada, K. Ueno A. Takeda, H. Sekiya. Kentaro Miuchi
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Direction-Sensitive Dark Matter Search --NEWAGE-- (New generation WIMP search with an advanced gaseous trackerexperiment) with H. Nishimura, T. Tanimori, H. Kubo, K. Hattori, C. Ida, S. Iwaki, S. Kabuki, A. Takada, K. Ueno A. Takeda, H. Sekiya Kentaro Miuchi (Kyoto University)
OUTLINE Motivation Methods Surfacemeasurement Latest activities Summary
1.Motivation“WIMP-wind”detection PLB 578 (2004) 241 SOLAR SYSTEM220 km/s WIMPV0 =230 km/s low pressure gasforward recoilsshort tracks The WIMP-wind
WIMP WIND γ F • WHY “Direction-sensitive” ? • Large mass for exclusion (and indication) • BUT Annual modulation is not enough… • Direction-sensitive for a concrete evidence and further study of halo dark matter Annualmodulation direction
expectedsensitivities 0.3m3year 3m3year • Expected Sensitivities • Goal: Detect the WIMP-wind • low pressure ( CF4 0.05 bar )・large volume (1m3 × N)・radio-purematerials • CURRENT: pilot run • CF4 0.2 bar ・(0.3m)3 ・ normalmaterials
2 Methods (3D tracking device) NEWAGE-0.3a : 23×28×31cm3 Preprints: physics/0701085 K.Miuchi et.al TPC Particle tracks 40cm TPC e X readout(768ch) GEM(×10) Y readout(768ch) m-PIC (×5000) FAGA position encoder(1536ch) Position Encoder Feb.20, 2007 APPEAL07
2D imaging device:m-PIC (gas gain 5000) • 400mm pitch • 589824 pixels • 768+768 readout • Gas volume • DRIFT length 31cm • CF4 0.2bar gas 31cm gas volume • 100MHz, pipeline 30cm μPIC(Toshiba) • Readout electronics • 768 anode + 768 cathode • Digital (LVDS) signals at ASD • (X,Y,T) at the position encoder TPC system
n q p Proton tracks 30cm 252Cf n Z(drift) • TPC Performanceplease note: these performance are still in progress • nuclear tracking • CF4+C4H10(9:1) 0.2 atm • n -> p forward scattering (emulation of WIMP -> F scatterings) 15cm 0cm -15cm -15cm 15cm X Y 252Cf(NE45°zenith35°) CF4+C4H10252Cf run 0 Recoil directionimage Jan 27, 2007 3rd MPGD workshop 1 Cos q
Other parameters (still in progress) • Energy resolution 50%(FWHM) @ 5~8 MeV ~70%@100keV • Position resolution 800μm (rms) • angular resolution ~25° (HWHM)
K.Miuchiet.al.,PLB654 (2007) 58 • Surface run① • 2006 Nov.1st ~ Nov.27th • exposure 0.15 kg days (=0.0089kg ×16.7days) • @Kyoto university (N35.03E135.783) • Energy spectrum(conventional method) Energy spectrum
Surface run ② • The sky map (by nuclear recoil tracks) • flat neutron background is seen North sky view seen by C and F nuclei(100-400keV) • DM direction
Surface run ③ • Cosθ distribution • consistent with a flat distribution Cosθ分布 (100-400keV) FIRSTDirection-sensitiveResults! WE AREHERE DM limit • First step to theNEWAGE Jan 27, 2007 3rd MPGD workshop
Recent activities Sensitivity improvement Scaling-up
NEWAGE@ Kamioka • Kamioka mine • 2700m w.e depth Lab-B SK • stable operation • Background Study XMASS 100kg Kamioka Kyoto
underground measurement 2007 2008 JanMar July AugDec DM run3 Comissioning run DM run 1 DM run 2 Comissioning run DM run exposure [kg∙days] 0.87 0.23 ¼ volume full volume • Total 0.61kg・days • BGrate surface run×40% (src:detectorcomponents) • Materialscreening,started black:surface blue:underground(preliminary)
Scaling-up • NEWAGE-0.3b performance test just started detection volume 31×31×50cm3(cf. NEWAGE-0.3a: 23×28×31cm3 ) • low pressure gascurrent 0.2 bar / design 0.05 bar • to lower the threshold (100keV -> 30keV) 60cm • Further R&Ds • readout pixel-type ASIC “QPIX” (with KEK)
SUMMARY NEWAGE:direction-sensitiveDMexp. Surfacerun:FirstDirection-sensitiveresults BG-reductionandscaling-upstudiesareon-going
Concluding message former JEDI (2005) JapaneseEnthusiasticDark matterInvestigator I hope NEWAGE becomes “A NEW HOPE” soon…