Underground Experiments at Kamioka Observatory

Hiroyuki Sekiya ICRR & Kavli-IPMU(WPI), University of Tokyo May. 21 2013 Waseda Univ. Kamioka Observatory

• Located underground in Kamioka Mozumi zinc mine at a Tokyo 2700 m.w.e. depth. Kyoto • 2km horizontal access by cars

Mt. Ikenoyama (1369m)

Surface Lab. 1000m Entrance 1800m Underground Lab.s

TPC Paris 2012 12/19/2012 H. Sekiya 2 Kamioka Underground Map 2013

KamLAND 赤 n bb は Super-Kamionade n 詳 XMASS CANDLES し Dark bb CLEAN matter ROOM1 く n 話せ EGADS ま n IPMU Lab NEWAGE CLIO す Dark Matter CLEAN Graviational wave ROOM2

Waseda Univ. 21/5/2013 H. Sekiya 3 歴代実験リスト（Kamiokandeで時期分け）

– KAMIOKANDE(1983-) • ELEGANT(DM, double beta) – Super-Kamiokande-I(1996-) • LISM(重力波 20m干渉計) • みのわ研(bolometer/stilbene/CaF2), – Super-Kamiokande-III/IV(2006-) • K2K • CLIO(重力波 100m干渉計) – Super-Kamiokande-II(2002-) • XMASS • XMASS 100kg, XMASS-II(鈴木聡さん) • NEWAGE • KamLAND • CANDLES • KamLAND-Zen • T2K • EGADS • KAGRA(重力波 3km干渉計) – Hyper-Kamiokande(201?-)

Waseda Univ. 21/5/2013 H. Sekiya 4 Kamioka Underground in 1980’s

KAMIOKANDE

Proton decay ELEGANT V Solar n Dark Matter + BG atmospheric n double beta decay

小柴時代

Waseda Univ. 21/5/2013 H. Sekiya 5 KAMIOKANDE

• 1983- 3000t Water Čerenkov Detector

– For proton decay seacrch

Waseda Univ. 21/5/2013 H. Sekiya 6 KAMIOKANDE

– 1987.2.23 16:35±1min Large Magellanic Cloud 1987A

Phys. Rev. Lett. 58(1970)1940

Waseda Univ. 21/5/2013 H. Sekiya 7 KAMIOKANDE

• Solar neutrino(～1995) Phys. Rev. Lett. 77 (1996) 1683 2 +

4p➔ He+2e +2νe

/sec/MeV) 2

- Water Cherenkov - nx + e -

→ nx + e Neutrino Neutrino (cm Flux

Neutrino energy (MeV)

• Homestake 37Cl (>814keV)

ApJ. 496 (1998) 505

Waseda Univ. 21/5/2013 H. Sekiya 8 ELEGANT V

• Rare event search detector complex – NaI dark matter search (Inelastic, 127I:57.6keV) – 100Mo double beta decay NIM 302(1991) 304

Waseda Univ. 21/5/2013 H. Sekiya 9 ELEGANT V Nucl. Phys. B (Proc. Suppl.),35 (1994) 372 • 結果 (BG subtraction…) Nucl. Phys. B (Proc. Suppl.),35 (1994) 400

相当低BG!

• その後、大塔コスモ観測所へ – ELAGANT IV CaF2(Eu) →CANDLESとして戻ってくる – NaIもPICOLONとしてKamLANDへ Waseda Univ. 21/5/2013 H. Sekiya 10 Kamioka Underground 90’s-2001

Super-Kamionade n

SK倉庫

ミニ重力波暗黒

戸塚時代

Waseda Univ. 21/5/2013 H. Sekiya 11 Super-Kamiokande I

• 50kton pure water Cherenkov detector • 11146 50cm PMTs in Inner Detector • 1885 20cm PMTs in Outer Detector

Physics targets

Atmospheric ν

3.5 MeV ~20 ~100 ~1 GeV TeV Low energy

Waseda Univ. 21/5/2013 H. Sekiya 12 Atmospheric neutrino

Waseda Univ. 21/5/2013 H. Sekiya 13 Super-Kamiokande

• e-m separation

Separation power >99%@1GeV

Waseda Univ. 21/5/2013 H. Sekiya 14 Super-Kamiokande

• Evidence for oscillation of atmospheric neutrino (1998)

Waseda Univ. 21/5/2013 H. Sekiya 15 K2K (1999-)

• KEK to Kamioka 250km

Phys.Rev.D74:072003,2006

Waseda Univ. 21/5/2013 H. Sekiya 16 Solar neutrino

Target Data / SSM (BP2000.2) ・ Homestake 37Cl 0.34±0.03 ・ SAGE 71Ga 0.55±0.05 いろんな実験で・ GALLEX+GNO 71Ga 0.55±0.05 ニュートリノが足りなかった。・ Kamiokande e- (water) 0.55±0.08

+0.20 7.6 +1.3 SNU 1.0 -1.1 -0.16

+7 71 -6 0.55±0.08 Theory

2.56 ±0.23 Experiment

Cl Homestake Kamioka H2O SAGE Ga GALLEX/GNO

Waseda Univ. 21/5/2013 H. Sekiya 17 SK+SNO • SK-I data

SNOではD2O targetなので

太陽ニュートリノ問題はニュートリノ振動によると解決！

Waseda Univ. 21/5/2013 H. Sekiya 18 ニュートリノ振動の仕方を見ていた

Target Data / SSM(BP2000.2) n2002 data ・ Homestake 37Cl 0.34±0.03 ・ SAGE 71Ga 0.55±0.05 ・ GALLEX+GNO 71Ga 0.55±0.05 ・ Super-K e- (water) 0.465±0.016 ・ SNO CC d (D2O) 0.349±0.020 ・ SNO NC d (D2O) 1.01 ± 0.13

1.01±0.13

Waseda Univ. 21/5/2013 H. Sekiya 19 蓑輪研神岡地下暗黒物質実験

• 1999-2003 – LiF/NaF bolometerを用いたスピンに依存した相互作用に特化した暗黒物質探索 • 2003 – Stilbene単結晶を用いた方向に感度を持った暗黒物質探索 • 2004-2005

– CaF2(Eu)を用いたスピンに依存した相互作用に特化した暗黒物質探索

Waseda Univ. 21/5/2013 H. Sekiya 20 貧者の19F • Neutralino-nucleus cross section M M 2 2 m   N   4G m C  N N F N N M  + M N Reduced mass G Enhancement factor F Fermi coupling constant SD SI SI 2 ~~nucleon spin CN  CN + CN (CN  A ) p N ~~in the nucleus SD 2 J +1 n N CN  ap Sp + an Sn  N N J ap’ an : χ-nucleon coupling~~~~

Isotope J N N 19F 1/2 0.441 -0.109 F has opposite sign of N/N 7Li 3/2 0.497 0.004 compared to Na, I, Ge, Xe. 23Na 3/2 0.248 0.020 73Ge 9/2 0.009 0.372 127I 5/2 0.309 0.075 129 ap, an へユニークな制限を付けられる Xe 1/2 0.028 0.359 131Xe 3/2 -0.009 -0.227

~~Waseda Univ. 21/5/2013 H. Sekiya 21 SI or SD?~~

~~Waseda Univ. 21/5/2013 H. Sekiya 22 Fを検出器に • Bolometer~~

~~NaF Crystal~~

~~NTD thermistor~~

~~Waseda Univ. 21/5/2013 H. Sekiya 23 駐車場の片隅で~~

~~• Installation started in Nov. 1999 • LiF run: 22 Nov. 2001- 12 Jan. 2002 • NaF run: 23 Dec. 2002 – 24 Jan. 2003 Waseda Univ. 21/5/2013 H. Sekiya 24 LiF/NaF bolometer結果~~

~~4.1 kg days (LiF) 3.4 kg days (NaF)~~

~~• BGが高いものの。。。~~

~~Waseda Univ. 21/5/2013 H. Sekiya 25 Organic single crystal scintillator • 暗黒物質の風を捕える WIMP wind Revolution 30km/s Cygnus 今日(5/21)の早稲田での風向き~~

~~Sun VE=232 km/s DARK HALO (Maxwellian)~~

~~Ｖ０＝220km/s Velocity distribution~~

~~16:30~~

~~Waseda Univ. 21/5/2013 H. Sekiya 26 Stilbene scintillator~~

~~重荷電粒子の入射方向によってクエンチングファクターが異なる Z. Phys. 162 (1961) 122 trans-stilbene 6.9MeV alphaに対する応答~~

~~低エネルギー中性子で実際に測定した PLB 571(2003) 132~~

~~@東工大~~

~~7%の差! Quenching Factor Quenching~~

~~Recoil Energy[keV] Waseda Univ. 21/5/2013 H. Sekiya 27 Bolometer破却後の測定神岡では軸に対して８０度変化する~~

~~Bolometerのシールド N XMASSのPMT (浜松R8778) ELEGANTのNaI (堀場製作所)~~

~~Waseda Univ. 21/5/2013 H. Sekiya 28 Stilbeneの結果 arXive:astro-ph/041125~~

~~4-6keVeeのpower spectrum~~

~~• 世界初の方向感度による制限！~~

~~• 実はNaIでリミット出した方が良い→CaF2(Eu)実験へ~~

~~Waseda Univ. 21/5/2013 H. Sekiya 29 CaF2(Eu)~~

~~• CANDLESのpure CaF2にEuF3をドープ~~

~~Waseda Univ. 21/5/2013 H. Sekiya 30 CaF2(Eu)の結果 • 明らかにEuがBG源だけど Phys.Lett.B633(2006)195~~

~~ap • いまだ神岡史上最高の結果！~~

~~Waseda Univ. 21/5/2013 H. Sekiya 31 Y.Suzuki Era~~

~~KamLAND n bb~~

~~Super-Kamionade n XMASS CANDLES Dark bb ココ matter ! n~~

~~EGADS n IPMU Lab NEWAGE CLIO Dark Matter CLEAN Graviational wave ROOM2~~

~~Waseda Univ. 21/5/2013 H. Sekiya 32 XMASS 100kg Prototype • Single phase LXe scintillator 54 2-inch low BG PMTs Hamamatsu R8778 16% photo- coverage Liq. Xe (31cm)3 OFHC cubic chamber~~

~~MgF2 window~~

~~Waseda Univ. 21/5/2013 H. Sekiya 33 Final 100 kg prototype~~

~~• To remove wall effects Active veto~~

~~Fiducial PTFE light guide 10cm 3 10X10X10cm (UV reflection) (~3 kg Xe) 6 pieces 10cm 10cm~~

~~Waseda Univ. 21/5/2013 H. Sekiya 34 “XMASS-II” by S.Suzuki • 2 phase detector (15kg Xe) Astropart. Phys. 20(2003) 79~~

~~R8778 x7 x2~~

~~Waseda Univ. 21/5/2013 H. Sekiya 35 “XMASS-II” • 実際の検出器~~

~~Waseda Univ. 21/5/2013 H. Sekiya 36 “XMASS-II” • S2 triggerにすべきだったけど,結構Low BG~~

~~2007 ICRR共同利用成果発表会~~

~~Waseda Univ. 21/5/2013 H. Sekiya 37 KamLAND (2002-)~~

~~• Ultra lowBG Liquid scintillator for anti-neutrino detector~~

~~Waseda Univ. 21/5/2013 H. Sekiya 38 KamLAND Physics Targets • The power of the delayed coincidence~~

~~Waseda Univ. 21/5/2013 H. Sekiya 39 KamLAND初期の結果していた~~

~~PRL 100 (2008) 221803~~

~~tanq12~~

~~• すごい！~~

~~Waseda Univ. 21/5/2013 H. Sekiya 40 今~~

~~Waseda Univ. 21/5/2013 H. Sekiya 41 ニュートリノ物理 double betaの実験は重要 PMNS Majorana framework phase x~~

~~octant of q Dirac CP 23 phase d~~

~~Oscillation in matter mass hierarchy matter potential~~

~~• 三角関数との戯れ Waseda Univ. 21/5/2013 H. Sekiya 42 Double beta decay 第3回CRCタウンミーティング~~

~~• 自然は親切で、これをテストする系を提供→二重ベータ崩壊 • 罠の可能性も~~

~~Waseda Univ. 21/5/2013 H. Sekiya 43 Double beta decay~~

~~Waseda Univ. 21/5/2013 H. Sekiya 44 Double beta decay experiments • 選択肢がいろいろ用意されている~~

~~• KamLAND-Zen 136Xe, CANDLES 48Ca~~

~~Waseda Univ. 21/5/2013 H. Sekiya 45 KamLAND-Zen~~

~~• 中心部のbaloonに136Xe320kg導入 – いかにきれいに作れるかが勝負~~

~~Waseda Univ. 21/5/2013 H. Sekiya 46 KamLAND-Zen~~

~~Waseda Univ. 21/5/2013 H. Sekiya 47 KamLAND-Zen~~

~~Waseda Univ. 21/5/2013 H. Sekiya 48 CANDLES III(U.G.)~~

~~Waseda Univ. 21/5/2013 H. Sekiya 49 CANDLES~~

Waseda Univ. 21/5/2013 H. Sekiya 50 CANDLESIII (U.G.) • Pros: – Largest Q value (4.27 MeV) • large phase space factor • almost background free (g: 2.6 MeV, b: 3.3 MeV) • Cons: – Low Natural abundance (0.187%) • large detector • Enrichment

~~Waseda Univ. 21/5/2013 H. Sekiya 51 伝統の低BG技術~~

~~Waseda Univ. 21/5/2013 H. Sekiya 52 48Ca濃縮~~

~~Waseda Univ. 21/5/2013 H. Sekiya 53 Super-Kamiokande IV Detector~~

~~• SK-IV: 2008年10月より – 20’’ PMTs x 11129 for ID – 8’’ PMTs x 1885 for OD – New electronics • software trigger (dead time free) • この夏ＨＶ入れ替え予定~~

~~42m~~

~~39.3m~~

~~Waseda Univ. 21/5/2013 H. Sekiya 54 SKのアプローチ~~

~~diag~~

~~Majorana term~~

~~加速器、大気ニュートリノ観測太陽ニュートリノ観測 SKでの検出原理~~

~~Waseda Univ. 21/5/2013 H. Sekiya 55 Solar neutrino observation~~

~~• Check the direct signal of the MSW effect. Solar matter effect Earth matter effect Energy spectrum up-turn Flux day/night asymmetry~~

~~Neutrino survival probability Night>Day : about 2% level~~

~~Vacuum Matter oscillation oscillation dominant dominant~~

~~See this up-turn!~~

~~Waseda Univ. 21/5/2013 H. Sekiya 56 Lowering threshold & BG in SK-IV~~

• Main BG source is 214Bi(b-decay Q=3.27MeV) from 222Rn emanated from PMTs. It seems to be accumulated at the bottom of the tank. • To prevent their invasion of fiducail volume by water convection, very precisely temperature-controlled (±0.01oC) water is supplied to the bottom.

~~Temperature gradation in Z 3.5MeV-4.5MeV The difference is only 0.2 oC Return to Event distribution Water system~~

~~Purified Water supply r2~~

~~Waseda Univ. 21/5/2013 H. Sekiya 57 Lowered background in SK-IV~~

~~Event rates Solar angular distribution~~

~~4.0-4.5MeV(kin.) 3.5~4.0MeV(kin.)~~

~~SK-III~~

~~kton SK-III SK-IV~~

~~Stable low event/day/ background level~~

~~SK-IV 8B n signal +113 763 -111~~

~~Clear Solar peak ~7σ level 3.5MeV threshold is achieved!~~

~~Waseda Univ. 21/5/2013 H. Sekiya 58 Recoil electron spectrum SK-I,II,III,IV Distortion due to E dependence of 1) Oscillation survival probability DATA/Unoscillated MC 2) dm/de~~

~~2 sin θ13=0.025 2 2 -5 2 sin θ12=0.304 , Δm =7.41∙10 eV~~

~~2 2 -5 2 sin θ12=0.314 , Δm =4.8∙10 eV Flat probability Flat prob., dσ ratio~~

~~8 6 2 f B=5.25×10 /(cm ∙sec) 3 2 fhep=7.88×10 /(cm ∙sec)~~

~~•• UnoscillatedUnoscillated shape shape is favored is favored ~1.1 to 1.9 ~1.1 s to 1.9 ~~

~~Waseda Univ. 21/5/2013 H. Sekiya 59 Comparison with others~~

~~SNO KamLAND~~

~~Super-K~~

~~BOREXINO~~

~~• Super-K spectrum is the most precise!~~

~~Waseda Univ. 21/5/2013 H. Sekiya 60 Day-Night Amplitude SK-I,II,III,IV Day-Night Asymmetry 20%~~

~~10% Day-Night amplitude -2.8 ±1.1(stat) ±0.5(sys)% 0~~

~~-10%~~

~~-20% 2 sin θ12=0.314 2 -5 2 -30% Δm21 =4.8∙10 eV~~

~~• [email protected] level! -40%~~

~~Waseda Univ. 21/5/2013 H. Sekiya 61 Global (All solar +KamLAND) Oscillation Analysis 2 q13 (Dm12 ,q12) Solar+KamLAND Best fit 2 +0.017 sin θ13=0.030 -0.015~~

~~5σ Solar+KamLAND 4σ Best fit 2 +0.013 sin θ12=0.304 -0.013 +0.20 3σ m 2=7.44 x10-5 eV2 Solar D 12 -0.19 Combined 2σ Data KamLAND 1σ~~

~~Daya Bay/Reno (0.025)~~

~~Consistent with reactor experiments!~~

~~Waseda Univ. 21/5/2013 H. Sekiya 62 Atomospheric neutrino~~

~~• Reacter neutrinoでq13が決まったので, q23のほうが、、、~~

~~Waseda Univ. 21/5/2013 H. Sekiya 63 Statistical PID _ • SK can separate ne from ne statistically. _ n -like ex) ne-like e Super-K IV Multi-GeV 1ring e-like CCnonQE interactions MC~~

~~Number of decay-e >0~~

~~ne-like + SK 4 data (448.6 days) Number of decay-e =0~~

~~anti ne-like~~

~~_ Number of decay-e ne-pulity 36.7% ne-pulity 60.5% Latest results • むしろMHやdを議論する時代~~

~~Waseda Univ. 21/5/2013 H. Sekiya 65 t appearance PRL 110(2013)181802 • ついに高統計NN解析にて! SK-I+II+III~~

~~Waseda Univ. 21/5/2013 H. Sekiya 66 Sterile neutrino~~

~~Waseda Univ. 21/5/2013 H. Sekiya 67 T2K 市川「ニュートリノフロンティアの融合と進化」4/21 • J-PARC(Tokai) to Kamioka~~

~~Waseda Univ. 21/5/2013 H. Sekiya 68 Indication: non zero q13~~

~~Waseda Univ. 21/5/2013 H. Sekiya 69 During shutdown,observed @ Reacter~~

~~Waseda Univ. 21/5/2013 H. Sekiya 70 ne appearanceの現状~~

~~Waseda Univ. 21/5/2013 H. Sekiya 71 nm disappearanceの現状~~

~~Waseda Univ. 21/5/2013 H. Sekiya 72 Proton decay • SK-I+II+III+IV~~

~~Waseda Univ. 21/5/2013 H. Sekiya 73 暗黒物質探索 • Self-annihilationにより探索 – Directional fluxによる探索~~

~~太陽内での散乱(主にSD), 地球内での散乱(主にSI) による減~~

~~速過程があるので、散乱断面積pに対する制限がでる – Diffuse fluxによる探索 dark halo からの  +   n + n を直接~~

~~対消滅断面積・速度分布<Av>に対する制限がでる~~

~~Waseda Univ. 21/5/2013 H. Sekiya 74  太陽から地球まで~~

~~Waseda Univ. 21/5/2013 H. Sekiya 75 太陽方向分布~~

~~Waseda Univ. 21/5/2013 H. Sekiya 76 SK solar Wimp search結果 • Low mass に関してはIceCubeより良い~~

~~• SDに関しては直接探索よりもよく,best limit!~~

~~2 cm~~

~~Waseda Univ. 21/5/2013 H. Sekiya 77 地球でのトラップ~~

~~Waseda Univ. 21/5/2013 H. Sekiya 78 大気ニュートリノのサンプル(zenith分布)で~~

~~• 地球のコアからくるイベント~~

~~Waseda Univ. 21/5/2013 H. Sekiya 79 SK Earth Wimp search結果~~

~~• SI 現在再解析中(少し古い結果) – 直接探索には及ばない~~

~~Waseda Univ. 21/5/2013 H. Sekiya 80 Diffuse WIMP search~~

~~• HOT TOPICS: positron excess by AMS/PAMELA/FERMI~~

~~+  +   nn ,W W ,bb ,m m ...ne /m /t~~



~~Waseda Univ. 21/5/2013 H. Sekiya 81 銀河中心に暗黒物質多い • NFW halo profile~~

~~2 ~r 銀河中心方向にピーク~~

~~Long lived unstable dark matter ~r~~

~~銀河中心方向に対する角度分布でみてfit するべし~~

~~Waseda Univ. 21/5/2013 H. Sekiya 82 銀河中心方向分布~~

~~Waseda Univ. 21/5/2013 H. Sekiya 83 Diffuse WIMP search現状 • 仮の結果(w/ Bug) AMS~~

~~Waseda Univ. 21/5/2013 H. Sekiya 84 Search for SN relic neutrinos~~

~~• All of the core collapse supernovae that have exploded throughout the history of the Universe have released neutrinos, which should still be in existence.~~

~~SN1987a Credit: X-ray: NASA/CXC/PSU/S.Park & D.Burrows.; Optical: NASA/STScI/CfA/P.Challis~~

~~Many SRN models that predict both the flux and the spectrum of anti-neutrino have been constructed.~~

~~Waseda Univ. 21/5/2013 H. Sekiya 85 Super-K sensitivity • SK-I+II+III result is only factor 2 higher than models! K.Bays et al., Phys.Rev.D85, 052007 (2012) Current SK BG (spallation + solar n)~~

~~Analysis threshold~~

~~Model predictions Models are parameterized in Tn of Fermi-Dirac emission~~

~~For LMA model Ando et al., (2005) Combined 90% C.L.: BG should be reduced < 5.1 ev / yr / 22.5 ktons 4 < 2.7 /cm2/s (>16 MeV) ～O(10 )~~

Waseda Univ. 21/5/2013 H. Sekiya 86 Beacom and Vagins, PRL, 93:171101, 2004 GADZOOKS! Project Gadolinium Antineutrino Detector • 0.2% Gadolinium sulfate in SK for Zealously Outperforming supernova relic neutrino search. Old Neutron tag (signal) efficiency : 90% Kamiokande, Super! Background reduction : 2x10-4

_ ne can be identified by the delayed coincidence technique Waseda Univ. 21/5/2013 H. Sekiya 87 EGADS Evaluating Gadolinium’s Action on Detector Systems R&D items  Water purification with gadolinium sulfate  Keep water transparency with gadolinium sulfate From • Effects on Super-K components/materials Jan. Transparency • Neutron background and its effects 240 PMTs measurement • Detection efficiency Main water Pre-treatment circulation system system

~~Waseda Univ. 21/5/2013 H. Sekiya 88 UDEAL 200 ton tank~~

~~15 ton tank for pre-treat~~

~~Gd water Circulation system pre-treatment system TPC Paris 2012 12/19/2012 H. Sekiya 89 Status~~

~~• Aug.2011- Present PMTs are not mounted yet~~

~~Long term stability and quality check – 0.2% Gd-loaded water circulation (w/o 200t tank) Selective filtration system uses a molecular size band- pass scheme to filter the water.~~

~~Confirmed Gd-kept eff. > 99.9% 85% water transparency of SK water~~

~~Waseda Univ. 21/5/2013 H. Sekiya 90 NEWAGE –The direction sensitive DM search- New general WIMP search with an Advanced Gaseous tracker Experiment~~

• Motion of Earth makes the distinctive WIMP signal. • Low pressure TPCs detect the direction of nuclear recoils. • F has good sensitivity via SD interaction. WIMP wind CF4 base gas. Revolution 3 Cygnus CF4 0.05 atm 3 m year 30km/s Sun MWIMP=80GeV, p-WIMP=0.1pb V =232 km/s E DARK HALO (Maxwellian) Ｖ０＝220km/s

~~F low pressure~~

~~F CF4 F~~

~~Waseda Univ. 21/5/2013 H. Sekiya 91 The Detector: micro-TPC (mPIC+GEM)~~

~~• NEWAGE-03a detector +8.2kV GEM (8-segmented) micro-TPC~~

~~gas : CF4 • size : 28x23cm 31cm 0.2atm • thickness : 50mm • hole : 70mm +915V • pitch : 140mm 5mm +605V +455V~~

~~m-PIC •size : 30x30cm Anodestrips Cathode strips 400μm~~

~~400μm~~

~~30cm~~

~~Waseda Univ. 21/5/2013 H. Sekiya 92 TPC Readout System 2012 JINST 7 C02023 TPC • Digital 3D-hits (track) X (Anode) Y (Cathode) • Analog charge (energy) readout（768ch） readout（768ch）~~

~~Data acquisition scheme~~

~~FPGA position encoder（1536ch） Memory board V 100MHz FADC 100MHz M PC pipeline E TPC system Analog sum~~

~~Waseda Univ. 21/5/2013 H. Sekiya 93 2nd underground measurement • From Jan. to May. 2012~~

~~• CF4 0.2atm:exposure:0.140 kg・days • Lowered threshold by FPGA improvement • Directional analysis is ongoing.~~

~~1st measurement 2nd measurement~~

~~Waseda Univ. 21/5/2013 H. Sekiya 94 Further improvement • NEWAGE-0.3b detector @ Kamioka~~

~~– CF4 0.1atm operation – 60cm drift • drift field : 625 V/cm/atm • drift velocity : 8.5 cm/ms~~

~~~40o down to 50keV~~

~~0.1atm 0.2atm~~

~~Waseda Univ. 21/5/2013 H. Sekiya 95 XMASS – Simple and Clean LXe Scintillator- Xenon detector for Weakly interacting MASSive Particles~~

~~Simplicity – Single phase LXe scintillator – Simple structure like Super-K Expected WIMP spectrum 10-3 -44 -2~~

~~Cleanliness p=3×10 cm 50GeV WIMP~~

~~– Made of pure materials keV – Xe purification technologies 10-4 • distillation system~~

~~10-5 Xe has the advantage Counts/day/kg/ for SI WIMPs 10-6~~

Waseda Univ. 21/5/2013 H. Sekiya 96 The Detector • 10m x f10m water shield for external BG • 857 kg Liquid Xe within PMT holder. – Largest mass among DM detectors • 642 hexagonal PMTs on 80cm pentakisdodecahedron

~~Construction was completed in Oct 2010~~

~~Waseda Univ. 21/5/2013 H. Sekiya 97 Inside of the pentakisdodecahedron~~

~~• Photo coverage is 62.4% yield 14.7 photoelectron/keV threshold 0.3keVee~~

6th TPC Paris 2012 12/19/2012 H. Sekiya 98 Pure components • More than 250 components RIs of all the components were measured with HPGe and low RI materials were selected. PMT(R10789) 3 HPGe detectors in Kamioka

~~C1020(OFHC) Sum of other components RI: Compared w/ RI: /one PMT SUS304 screws 642 PMTs U 0.70±0.28 mBq U <35% Th 1.51±0.31 mBq Th <35% 40K <5.1 mBq 40K <20% 60Co 2.92±1.61 mBq 60Co <20% LEDs~~

Waseda Univ. 21/5/2013 H. Sekiya 99 Astoparticle Physics 31, (2009) 290 Distillation system • Commercial “pure Xe” contains ~0.1ppm Kr 85 -11 – K / K = 1.2×10 t =10.8 year, Qβ = 687keV – 5 order reduction was indispensable.

~~Boiling point (@0.2MPa) Xe 178K 4m Kr 140K~150K~~

~~We established Xe purifiaction by distillation~~

~~• 1 ton LXe = 170 m3 gas Xe Process speed: 4.7kg/hr → 10 days • Confirmed Kr < 2.7ppt by API-MS~~

~~Waseda Univ. 21/5/2013 H. Sekiya 100 Top PMT Response of the detector manipulator~~

~~57Co photoelectron spectrum Reconstructed vertex real data simulation 122keV real data simulation ~4% rms~~

~~59.3keV of W 136keV~~

~~Trigger efficiency total photoelectrons~~

~~• World highest LXe scintillation yields: 14.7p.e./keVee cf. 2.2 p.e./keVee @XENON100 • Lowest threshold~~

~~energy keVee 0.3keVee cf. 0.5keVee@CoGeNT Waseda Univ. 21/5/2013 H. Sekiya 101 Unexpected BG sources~~

~~• BG is 2 order higher than that had been expected.~~

~~p.e. Data BG simulation 238U & 210Pb of PMT Al seal~~

~~expected BG (PMT & components) counts/day/ ~1MeV(60Co peak)~~

~~total photoelectrons~~

• Major origin of BG was considered to be g GORE-TEX from PMTs, but the observed data seemed ~5keV to have additional surface BG. • Aluminum sealing parts for the PMT (btw metal body and quartz glass) contains 238U and 210Pb • GORE-TEX between PMT and holder contains modern carbon (14C) Waseda Univ. 21/5/2013 H. Sekiya 102 XMASS Full Volume: Low BG w/o PID

~~• Although extra BG sources were found, XMASS BG level is still competitive w/o rejecting electronic events. – XMASS has a competitive sensitivity to Light WIMPs & Axions~~

~~keV XMASS full volume 5591.4kg days~~

~~Evens/kg/day/ E. Aprile, 2010 Princeton • Fiducial volume analysis is ongoing.~~

~~Waseda Univ. 21/5/2013 H. Sekiya 103 arXiv:1211.5404 Low Mass WIMPs~~

~~• Set an upper limit on the WIMP-nucleon cross section for WIMPs with masses below 20GeV and excludes part of the~~

~~parameter space allowed by DAMA~~

~~5 2 CoGeNT cm~~

~~/day -40 n n - 10 DAMA 5~~

~~4 90%CL XMASS~~

~~WIMP keVee data  10-41 Band:Q.F uncertainty~~

~~/kg/ 3~~

~~10-42 CDMS 2~~

~~7GeV 10-43 1 12GeV 18GeV 10-44 0 0.5 1 1.5 [keVee2 ] WIMP mass [GeV/c2]~~

~~Waseda Univ. 21/5/2013 H. Sekiya 104 Quenching Factor/Leff uncertainty~~

~~Waseda Univ. 21/5/2013 H. Sekiya 105 Dark Matter Axion~~

~~• DAMA signal can be explained by electromagnetic interactions of non-relativistic Axions and NaI. [J. Collar, arXiv: 0903.5068] • XMASS has sensitivity to dark matter Axion g~~

~~through Axio-electric effect. aee~~

~~Limits on g~~

~~/day aee~~

~~aee g keV~~

~~DAMA allowed /kg/ data CoGeNT 2011 90%CL XMASS CDMS 2009~~

~~ma=3keV~~

~~[keVee]~~

~~Waseda Univ. 21/5/2013 H. Sekiya 106 Solar Axion~~

~~• XMASS has also sensitivity to solar axions that would be produced by Bremsstrahlung~~

~~and Compton effects (gaee ) in the Sun through the axio-electric effect.~~

~~N.B. Not gagg through Primakoff effect Expected spectrum based on A.V. Derbin arXive: 1206.4142v2~~

~~XMASS 4.5x1011~~

~~Waseda Univ. 21/5/2013 H. Sekiya 107 Plan • Fiducial analysis • Annual modulation analysis • Refurbishment~~

~~– Put OFHC Cu covers on PMTs 2 order w/o cover – In one year. Already started. reduction w/ cover • Next XMASS (5t)~~

~~– w/ New PMTs under development 5keV total p.e. – In three years~~

~~Waseda Univ. 21/5/2013 H. Sekiya 108 Another R&D: Spherical LXe TPC~~

~~• High electric field in XMASS (after XMASS-5t construction) +HV C2 Inspired by I.Giomataris JINST 3:P09007(2008)~~

~~形成される電場 Now making small chamber and Cockcroft HV HV遮蔽 S2 ガード (GND) E PMT e- e- e- HV電極電極挿入箇所 S1 電極針ガード付電極針~~

~~Before two phase detector, 109Cd 22keV was observed many studies about the Using 4mm wire charge amplification and the proportional scintillation in single phase LXe~~

~~NIMA 327 (1993) 203~~

~~Waseda Univ. 21/5/2013 H. Sekiya 109 現状~~

~~• まずは、ワイヤーで過去の検証~~

~~Waseda Univ. 21/5/2013 H. Sekiya 110 まとめ~~

~~• 神岡ではさまざまな最先端素粒子物理の研究ができてます。 • 宣伝２つ – 3rd Hyper-K Open meeting – CYGNUS 2013~~

~~Waseda Univ. 21/5/2013 H. Sekiya 111 Hyper-Kamiokande 3rd Open Meeting For the next decade’s flagship experiment~~

~~• 21 – 22 June, Kashiwa (Kavli IPMU), Japan~~

~~Fiducial vol.0.56Mt~~

~~Fiducial vol. 0.0225Mt~~

~~All those interested are welcome to join! SKの25倍の統計で！~~

~~Waseda Univ. 21/5/2013 H. Sekiya 112 HKの場所について~~

~~Waseda Univ. 21/5/2013 H. Sekiya 113 Mozumi Option~~

~~Waseda Univ. 21/5/2013 H. Sekiya 114 CYGNUS 2013 4th Workshop on Directional Detection of Dark Matter • 10 – 12 June, Toyama (&Kamioka), Japan~~

~~Waseda Univ. 21/5/2013 H. Sekiya 115 まとめ~~

• 神岡ではさまざまな最先端素粒子物理の研究ができてます。 • 宣伝２つ – 3rd Hyper-K Open meeting – CYGNUS 2013 • 将来の野望 – TPC in SK F • Low pressure F F • High pressure

~~Waseda Univ. 21/5/2013 H. Sekiya 116~~

~~Extra slides~~

~~6th TPC Paris 2012 12/19/2012 H. Sekiya 117 misc.~~

~~6th TPC Paris 2012 12/19/2012 H. Sekiya 118 Kamioka Underground~~

~~ICRR, University of Tokyo~~

~~RCNS, Kamioka Tohoku Observatory University~~

~~Gravitational Super- XMASS Wave NEWAGE CANDLES KamLAND Kamiokande projects~~

~~TPC Paris 2012 12/19/2012 H. Sekiya 119 SK Rn Free Air System~~

~~• 3000Bq/m3 -> 1mBq/m3~~

~~20m3/h~~

~~6th TPC Paris 2012 12/19/2012 H. Sekiya 120 Rn~~

~~TPC Paris 2012 12/19/2012 H. Sekiya 121 XMASS~~

~~6th TPC Paris 2012 12/19/2012 H. Sekiya 122 Schedule and Competitors~~

~~6th TPC Paris 2012 12/19/2012 H. Sekiya 123 Clean XMASS PMT HISTORY PMT~~

YEAR 2000 2002 2009 Model Prototype R8778 R10789 Material:Body glass Kovar Kovar QE 25% 25% 27-39% RI: w/ PMT base U [mBq/PMT] 50 18±2 0.70±0.28 Th [mBq/PMT] 13 6.9±1.3 1.51±0.31 40K [mBq/PMT] 610 140±20 <5.1 60Co [mBq/PMT] <1.8 5.5±0.9 2.92±1.61

~~• Clean PMT Base has also been developed.~~

~~H. Sekiya 124 Xe circulation system 4 x 180W refrigerator Gas circulation 30L/min PTR developed by KEK gas pump emergency gas pump Cable line 100L/min~~

~~filters Calibration line~~

~~Water tank~~

~~evaporator 3 Condenser 10 m 360W filters x 2 800kg 857kg gas storage Outer vacuum liquid pump 700L Liquid circulation 5L/min Liq. Storage H. Sekiya 125 Lab-C~~

~~Xe Circulation system~~

~~Distillation Water tank Tower Gas Xe tank LXe tank~~

H. Sekiya 126 Water shields for external BG • Active for m, passive for g,n Ex.) Fast n flux @Kamioka mine: 10m (1.15+0.12) x10-5 /cm2/sec Assuming all neutron’s energies are 10 MeV very conservatively

~~107 n generated~~

~~10m~~

~~[cm]~~

~~y water~~

Liq. Xe < 10-4 Water purification system count/day/kg keeps Rn < 1mBq/m3 X [cm] with 70 PMTs (20 inch) to detect Cerenkov light 5m tank is enough large to shield n and g GLA2010 3/29/2010 H. Sekiya 127

~~U chain Th chain~~

~~GLA2010 3/29/2010 H. Sekiya 128 Calibration System • Calibration source rod adopter (SUS304) source＋holder~~

~~(Exchangeble)~~

~~OFHC (C1020) rod~~

~~• Source list Isotopes Energy [keV] intensity diameter [Hz] [mm] (1) Fe-55 5.9 350 1.42 (2) Cd-109 22, 25, 88 800 1.42 (3) Am-241 59.5 485 0.15 (4) Co-57 122 100 0.21~~

~~H. Sekiya 129~~