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K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Direction-Sensitive Dark Matter Search --NEWAGE--
Kentaro Miuchi
(Kyoto University)
(New generation WIMP search with an advanced gaseous tracker experiment)
with H. Nishimura, T. Tanimori, H. Kubo,
K. Hattori, C. Ida, S. Iwaki, S. Kabuki,
A. Takada, K. Ueno
A. Takeda, H. Sekiya
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
OUTLINE
Motivation
Methods
Surface measurement
Latest activities
Summary
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
1 . Motivation “ WIMP-wind” detection
The WIMP-wind
WIMPV0 =230 km/s
SOLAR SYSTEM220 km/s
PLB 578 (2004) 241
low pressure gasforward recoilsshort tracks
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
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
WIMPWIMP WIND WIND γ γ
FF
Annualmodulation
direction
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Expected Sensitivities Goal: Detect the WIMP-wind
• low pressure ( CF4 0.05 bar ) ・large volume ( 1m3 × N )・ radio-pure materials
CURRENT: pilot run • CF4 0.2 bar ・ (0.3m)3
・ normal materials
0.3m3 year
3m3 year
expected sensitivities
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
2 Methods (3D tracking device)
Feb. 20, 2007 APPEAL07Position Encoder
PIC (×5000)
GEM(×10)
TPC
Particle tracks
e
Preprints: physics/0701085 K.Miuchi et.al
40cm
TPC
X readout ( 768ch ) Y
readout ( 768ch )
FAGA position encoder( 1536ch )
NEWAGE-0.3a : 23×28×31cm3
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Readout electronics• 768 anode + 768 cathode• Digital (LVDS) signals at ASD• (X,Y,T) at the position encoder
31cm
gas volume
TPC system
Gas volume• DRIFT length 31cm• CF4 0.2bar gas
100MHz, pipeline
2D imaging device: -PIC (gas gain 5000)
• 400mm pitch• 589824 pixels• 768+768 readout
30cm μPIC(Toshiba)
K. Miuchi
CF4+C4H10 (9:1) 0.2 atm
n -> p forward scattering (emulation of WIMP -> F scatterings)
Jan 27, 2007 3rd MPGD workshopRecoil direction image
252Cf( NE45° zenith35° )
10
Cos
n
p
CF4+C4H10
252Cf run
Proton tracks
n252Cf
YX-15cm
15cm
15cm
-15cm
30cm
Z(drift)
0cm
TPC Performanceplease note: these performance are still in progress
nuclear tracking
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Other parameters (still in progress)
Energy resolution 50%(FWHM) @ 5~8 MeV ~70%@100keV
Position resolution 800μm (rms)
angular resolution ~25° (HWHM)
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Surface run①2006 Nov.1st ~ Nov.27th
exposure 0.15 kg days (=0.0089kg ×16.7days)
@Kyoto university (N35.03 E135.783 ) Energy spectrum ( conventional method )
Energy spectrum
K.Miuchi et.al., PLB654 (2007) 58
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Surface run ②The sky map (by nuclear recoil tracks)
flat neutron background is seenNorth sky view seen by C and F nuclei(100-400keV)
DM direction
K. Miuchi Jan 27, 2007 3rd MPGD workshop
Surface run ③Cosθ distribution
consistent with a flat distribution
Cosθ 分布
(100-400keV)
DM limit
First step to theNEWAGE
WE ARE HERE
FIRST Direction-sensitive Results!
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Recent activities
Sensitivity improvement
Scaling-up
K. Miuchi
NEWAGE @ Kamioka•Kamioka mine•2700m w.e depth
•stable operation•Background Study
KamiokaKyoto
SKLab-B
XMASS100kg
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
underground measurement
2007 2008Jan Mar July Aug Dec DM run 1 DM run 2
¼ volume
DM run exposure
[kg∙days]
•Total 0.61kg ・ days•BG rate surface run ×40 % ( src: detector components )•Material screening, started
Comissioningrun DM run3Comissioning
run
0.23 0.87
black: surface
blue: underground(preliminary )
full volume
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Further R&Dsreadout pixel-type ASIC “QPIX” (with KEK)
Scaling-upNEWAGE-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
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
SUMMARY
NEWAGE: direction-sensitive DM exp.
Surface run: First Direction-sensitive results
BG-reduction and scaling-up studies are on-going
K. MiuchiK. Miuchi July 10, 2008 Dark Matter and Dark Energy
Concluding message I hope
NEWAGE becomes “A NEW HOPE” soon…
Japanese
Enthusiastic
Dark matter
Investigator
former JEDI
(2005)