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

Motivation

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

Methods

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 measuremant

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)

K. Miuchi July 10, 2008 　 Dark Matter and Dark Energy