Kiseki Nakamura (Kyoto university)

Transcription

1 2013/06/10 Kiseki Nakamura (Kyoto university) T.Tanimori (1), K.Miuchi (2), K.Kubo (1), T.Mizumoto (1), J.Parker (1), A.Takada (3), H.Nishimura (1), T.Sawano (1), Y.Matsuoka (1), S.Komura (1), Y.Yamaguchi (2), S.Nakaura (2) (1) Kyoto university department of physics (2) Kobe university department of physics (3) Kyoto university RISH What s NEWAGE? New result by NEWAGE-0.3a Commissioning of NEWAGE-0.3b Head-tail R&D with NEWAGE-0.1a Summary

2 rate [counts/kev/kg/days] cosq 1. Annual modulation (conventional) Large mass -> Solid or liquid detector Require for 3s : ~10000events 2. Direction sensitivity (new) Nuclear track -> Gas detector (or emulsion) Require for 3s : ~20events Expected energy spectrum σ SD =1pb M=100GeV target:f Few % of the annual modulation 100 recoil energy [kev] 200 Expected cosθ distribution σ SD =1pb M=100GeV target:f Nucleus θ DM Large difference in forward to back

3 3D tracking : m-tpc 2D : m-pic (400mm pitch) 1D : Drift timing (100MHz) gas: CF 4 76~152torr Analog sum Digital Flash ADC energy(charge) PC 3D track m-pic 400mm 30cm Typical gas gain ~5000(Ar 1atm) 30x30cm size is available GEM

4 Detector Name NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Detection volume 23 x 28 x 31 cm 3 30 x 30 x 41 cm 3 10 x 10 x 10 cm 3 Gas CF 4 152torr CF 4 76torr CF 4 152torr DAQ-mode mode3 mode5 mode5 Place Kamioka Kamioka Kobe Status DM search Commissioning Head-tail R&D 1st talk 2nd talk 3rd talk NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a 40cm 40cm 15cm

5 Detector Name NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Detection volume 23 x 28 x 31 cm 3 30 x 30 x 41 cm 3 10 x 10 x 10 cm 3 Gas CF 4 152torr CF 4 76torr CF 4 152torr DAQ-mode mode3 mode5 mode5 Place Kamioka Kamioka Kobe Status DM search Commissioning Head-tail R&D 1st talk 2nd talk 3rd talk Underground runs run# RUN5 (PLB2010)... RUN13 RUN14 RUN15 NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Period Mar 2013 April Detector 40cm NEWAGE-0.3a... NEWAEG-0.3a NEWAGE-0.3b 15cm 40cm Gas room temp... room temp without cooled circulation charcoal charcoal charcoal charcoal

6 Detector Name NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Detection volume 23 x 28 x 31 cm 3 30 x 30 x 41 cm 3 10 x 10 x 10 cm 3 Gas CF 4 152torr CF 4 76torr CF 4 152torr DAQ-mode mode3 mode5 mode5 Place Kamioka Kamioka Kobe Status DM search Commissioning Head-tail R&D

7 TPC 40cm Y readout (768ch) 31cm X readout (768ch) FAGA position encoder (1536ch) 23 x 28 x 31 cm 3 152torr CF 4 = 11.48g

8 Sensitivity Improvement a particle radon gas -> Low BG aiming 1/10 gamma rays DAQ upgrade -> Low threshold

9 radon, gamma, alpha: "clean" materials Time dependence of Rn rate measured by Rn detector to <1/10 radon emanation level NEWAGE-0.3a glass-reinforced fluoro-plastic NEWAGE-0.3a PTFE + copper wire

10 Radon: charcoal gas circulation system monitor radon rate (~6MeV) radon rate ~1/10 after days10 charcoal filter ~100g (TSURUMICOAL 2GS)) getter pump (SAES GETTER C400-2DSK) circulation (Teflon bellows pump) NEWAGE0.3a 152 torr CF4 gas without charcoal with charcoal cf:1e5counts/kg/days~1bq/m 3

11 Gamma: 1 length-cut energy vs length cut gamma rejection efficiency*: 8.1 x 10-6 n + gamma run (252Cf) gamma rejection efficiency gamma run (137Cs) * gamma rejection efficiency=electron detection efficiency

12 Gamma: 2 precise gain-map gas gain is not uniform in 30 x 30 cm 2 old gain map RUN5 new gain map RUN13 20cm 137Cs run remaining events after gamma rejection ( keV) 137Cs run remaining events after gamma rejection ( keV) gamma rejection 8.1e-6 gamma rejection 1.0e-6>

13 Underground run in 2012 (RUN13) Target gas: CF 4 152torr Fiducial volume: 14 x 13 x 31 cm 3 Target mass: kg Date: Jan. 23, Jan. 24, 2013 Live time: days Exposure: kg days DAQ trouble DISK trouble DAQ trouble

14 exposure: kg days spectrum threshold: 100keV 50keV rate: ~1/5 at 100keV cos θ distribution: flat measured energy spectrum measured cosq cygnus distribution keV combined detection efficiency applied cosq cygnus

15 measured by 252Cf simulation simulation (detector response considered) = detector response DM wind Input Parameters energy resolution angular resolution WIMP mass energy range Expected DM wind measured (RUN13) simulation (detector responce considered) DATA Comparison Scanning s DM, we set direction sensitive limit. SIM Expected cosθ distribution (DM) cosq cygnus cosq cygnus

16 150GeV threshold=100kev E resolution=30% Ang. resolution 55

17 K. Nakamura et al 2012 JINST 7 C02023 Detector Name NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Detection volume 23 x 28 x 31 cm 3 30 x 30 x 41 cm 3 10 x 10 x 10 cm 3 Gas CF 4 152torr CF 4 76torr CF 4 152torr DAQ-mode mode3 mode5 mode5 Place Kamioka Kamioka Kobe Status DM search Commissioning Head-tail R&D

18 Developments at Kyoto (surface lab) Larger GEM Large size ~ x2 Longer drift length PEEK drift cage Low BG ~ 1/10 Cooled charcoal Low pressure gas Low threshold ~ 1/2 DAQ upgrade

19 NEWAGE-0.3b PEEK + copper wire 41cm NEWAGE-0.3b glass-reinforced fluoro-plastic Significance estimation GEM 23x28 -> 31x31 cm2 Drift Cage 31 -> 41 cm PEEK 3 month measurement no-bg 2-bin method s p-dm(sd) = 268pb M DM = 100GeV : current angular resolution : 10deg improved : 20deg improved Detection volume: 2 x NEWAGE-0.3a PEEK for low BG

20 NEWAGE-0.3b : Detector wall Detection region (76torr CF 4 ) CF 4 Rn U Circulation with cooled charcoal a-decay (about 6MeV) Rn Radon rate : <1/10 Rn CF 4 CF 4 pump 500ml/min cooler 210K Radon Time rate dependence of Rn without charcoal charcoal 100g Rn cooled charcoal (10ml/min) cooled charcoal (500ml/min)

21 K. Nakamura et al 2012 JINST 7 C02023 Gas pressure: 152->76 torr (NEWAGE-0.3a ->NEWAGE-0.3b ) Comparing cosq distribution measured to simulation simulated cosq distribution measured cosq distribution 252 Cf neutron nuclear q measured simulation(s=49deg) F nucleus tracks 252 Cf c 2 -values for each angular resolution c 2 minimum is 49 (measured with DAQ-mode1)

22 K. Nakamura et al 2012 JINST 7 C02023 Gas pressure: 152->76 torr (NEWAGE-0.3a ->NEWAGE-0.3b ) Angular resolution: Detection efficiency: angular resolution detection efficiency 76torr 76torr 152torr Energy threshold with angular resolution: 100->50keV (by 152->76torr) (measured with DAQ-mode1)

23 clock discri th clock mode5 Strip information (for each clock) all Time Over Threshold Rise & Fall timing ( energy of each strip) Detector NEWAGE-0.3b NEWAGE-0.1a mode3 all Rise timing NEWAGE-0.3a mode1 x-y coincidence max, min only Rise timing NEWAGE-0.3b mode5 mode3 mode1 x strip y strip We confirmed DAQ-mode5 works with no bug

24 From Kyoto to Kamioka (Mar. 2013) Data aquisition m-tpc gas circulation We re visiting here at Kamioka tour

25 Measure clock of drift 4.7ms for 41cm -> v=8.7cm/ms Consistent to surface measurement clock(=10ns) Electric Field: 0.095kV/cm gas: CF 4 76torr 252 Cf PMT (trigger) 41cm

26 10 B (1.5mm thickness) coated glass Calibration with 10 B 10B(n,a)7Li reaction (Q=2.70MeV ~1.5MeV a) measured simulation Edge thermalized neutrons 252 Cf polyethelene

27 Drift cage Material: glass -> PEEK radon rate: <1/3 Further 1/10 with cooled charcoal Underground runs run# RUN5 (PLB2010)... RUN13 RUN14 RUN15 Period Mar 2013 April Detector NEWAGE-0.3a... NEWAEG-0.3a NEWAGE-0.3b Gas circulation room temp charcoal... room temp charcoal without charcoal cooled charcoal

28 Commissioning almost done (analysis tuning now) DM run started (RUN15-)

29 Detector Name NEWAGE-0.3a NEWAGE-0.3b NEWAGE-0.1a Detection volume 23 x 28 x 31 cm 3 30 x 30 x 41 cm 3 10 x 10 x 10 cm 3 Gas CF 4 152torr CF 4 76torr CF 4 152torr DAQ-mode mode3 mode5 mode5 Place Kamioka Kamioka Kobe Status DM search Commissioning Head-tail R&D

30 Head-tail recognition of nuclear track -> Sensitivity improvement: 3 ~ 10 times without head-tail recognition Expected sensitivity solid (with head-tail recognition) dotted (without) with head-tail recognition cosq cosq Phys. Lett. B 578(2004)241

31 mtpc: 10 x 10 x 10cm 3 readout: 400mm pitch GEM: polyimide, 100mmt gas: CF4, 152torr 10cm

32 clock clock discri th mode5 Strip information (for each clock) all Time Over Threshold Rise & Fall timing ( energy of each strip) Detector NEWAGE-0.3b NEWAGE-0.1a mode3 all Rise timing NEWAGE-0.3a mode1 x-y coincidence max, min only Rise timing NEWAGE-0.3b mode5 mode3 mode1 x strip y strip

33 observed Bragg Curve 130keV F track neutron

34 charge observed Bragg Curve g x = If symmetric, g=0 x g y =0.437 neutron y skewness g difference was observed

35 +x -y ±X run ±Y run +y -x parallel orthogonal X skewness orthogonal parallel Y skewness

36 sewness Energy dependence of parallel and orthogonal skewness statistically significant ( >70keV ) 5.1σ 7.1σ 4.1σ 誤差は統計誤差のみ To do for next the skewness definition improvement 3-dimensional track

37 Latest limit by NEWAGE-0.3a Direction sensitive limit updated: Commissioning of NEWAGE-0.3b Commissioning almost done & Started DM run Head-tail R&D using NEWAGE-0.1a 2-dim Head-tail can be statistically seen for >70keV

38 Latest limit by NEWAGE-0.3a Direction sensitive limit updated: Commissioning of NEWAGE-0.3b Commissioning almost done & Started DM run Head-tail R&D using NEWAGE-0.1a 2-dim Head-tail can be statistically seen for >70keV Thank you for your attention! TЁЯRA EDEN Mascot of NEWAGE "Daakumatan"