Sun Kee Kim Seoul National University Plan Sun Kee Kim Seoul National University Workshop on Double Beta Decay Search, Seoul, Oct. 15, 2009

40Ca100MoO4 Reference sample CaMoO4 from the CARAT company (Lviv, Ukraine)

HPGe measurements at Baksan 40Ca100MO4 single crystal (boule) # 29 m = 0.55 kg T = 475 hours K-40 ≤9,0*10-3 Bq/kg Tl-208 ≤7,5*10-4 Bq/kg 95% CL: Bi-214 ≤ 5,1*10-3 Bq/kg (68% CL) / (3,2+/-1,9)*10-3 Bq/kg Ac-228 ≤ 3,7*10-3 Bq/kg (68% CL) / (2,3+/-1,4)*10-3 Bq/kg *STILL UNDER MEASUREMET!

Backgrounds and signal for 6kg of 40Ca100MoO4 with 3 years data taking (GEANT4) Sensitivity 3kg (100Mo) : 48Ca depletion 5% FWHM resolution 4p active shielding 0.05 mBq/kg for 208Tl, 214Bi 3 years  6.0x1024 y (90% CL) (0.2~0.7 eV) Mo-100 2n Signal (m=0.4eV) Bi-214 Tl-208 10s significance Current best limit on 100Mo : 4.6x1023 by NEMO3 with 6.9kg 100Mo Claim by Klapdor-Kleingrothaus et al.  ~ 400 meV  Assuming optimistic theoretical value

Sensitivity of a pilot experiment 1 kg of Ca100MoO4 Main sources of background 22 decay of 48Ca (T1/22 = 41019 yr) 208Tl and 214Bi (both with 0.1 mBq/kg) A suppression of factor 10 for 214Bi by pulse-shape analysis is supposed. 88Y cosmogenic negligible Distributions for 100Mo are shown for: - T1/22 = 71018 yr - T1/20 = 1024 yr. T1/20 > 41023 yr at 90% CL over 1 years with 1 kg Ca100MoO4 T1/20 > 21024 yr 10 kgyr Ca100MoO4 T1/20  1025 yr 200 kgyr Ca100MoO4 T1/20  1026 yr 1000 kgyr Ca100MoO4 as low temperature bolometer NIMA 584 (2008) 334 F.A. Danevich Workshop on Double Beta Decay Search, SNU 16 Oct 2009

Cryogenic CaMoO4 Sensitivity 0.5% FWHM ->15 keV FWHM for low temp. (8-10keV for CUORICINO) 3 years, 6kg 40Ca100MoO4 => 0.06 events , no background limit! T1/2 = 2.0x1025 years expected <m> = 0.1 - 0.4 eV by 90% CL 5 years, 100 kg 40Ca100MoO4 , further background reduction, resolution improvement: 7.0x1026 years -> 20 – 70 meV Fully covers inverted hierarchy

Other projected sensitivities and some theoretical predictions Eth=10 keV (5 and 100 kg year) CaMoO4 CDMS 2008 SuperCDMS 25kg XENON10 2007 Bottino et al XENON100 6000 kgd Eth=1 keV (5 and 100 kg year) Trotta et al CMSSM, Ellis et al Ellis et al CMSSM, Markov chain Trotta et al Effective MSSM, Bottino et al

Possible configuration of the 1st round experiment Pilot experiment (to 2010) 40Ca100MoO4 produced in Russia : ~f5x5cm 4p CsI(Tl) active veto + 10 cm Pb +N2 gas+ Cooling Up to 4 crystals are possible with 2” PMT(APD) Internal background measurement Optimization of energy resolution study Very preliminary results 1st Experiment (from 2011) 40Ca100MoO4 : ~f5x5cm, 9 crystals, total 6kg Setup inside of KIMS shielding setup 3) 1st stage results 2nd Experiment (from ?) 40Ca100MoO4 : 100kg, Cryogenic technique

detector Cu 10-15 cm, Pb 20-25 cm, Cd 1-2 mm Polyethylene 20-30 cm Plastic scintillator light-guide Liquid scintillator CaMoO4 CsI(Tl) Cu 10-15 cm, Pb 20-25 cm, Cd 1-2 mm Polyethylene 20-30 cm N2 flux to remove air (Rn) F.A. Danevich Workshop on Double Beta Decay Search, SNU 16 Oct 2009

1st stage experiment (pilot experiment) 0.5-5kg CMO crystal Decisions on - Size/shape of each crystal - Light guide (?) - Operating temperature - Photon sensor (?) - Digitizer/ DAQ Separate shielding or KIMS shielding

100 kg Cryogenic detector 1st stage experiment (up to ~5 kg ?) -- should be carried out within the currently available budget. WCU, Basic science grants ISTC , Korea-Ukraine Cooperation fund Intermediate step could be 5kg Cryogenic detector (maybe possible w/o additional funding) 100 kg Cryogenic detector will need new budegt funding opportunity exists!

Basic Science Institute 라. 조직 및 연구비 ○ 초기에는 Site-Lab으로 출범 후 연차적으로 확대하여 최종 50여개의 연구단에 총 3,000명 규모로 운영  ~ 50 research teams ○ 연구단별 연평균 100억원 내외의 연구비를 10년간 지원하되, 과학자문위원회를 통해 3년 주기 평가  ~ 10M USD/year x 10 years ○ 해외석학을 통한 국내 연구역량 강화 및 확산 - 연구단에 국내 연구책임자급, Post-doc, 박사과정학생 등 국내인력의 다양한 참여 및 타 기관과의 공동연구 활성화 * Visiting scholar 제도 : 안식년을 맞은 교수들의 연구 참여 * 학․연 프로그램을 통한 학점인정으로 박사과정학생의 연구 참여 * 국내 타연구기관․대학간 공동연구프로그램 운영 * 해외석학의 국내대학 교육프로그램 참여 등

Strengthening the international collaboration The second Japan-China-Korea Trilateral Ministerial Meeting on Science and Technology Cooperation was held on Sunday, 24 May in Tokyo. China, Japan, and Korea issued a joint statement on science and technology cooperation … The three Ministers also noted the importance of research collaboration through use of research facilities and exchanging personnel in the field of big science such as high energy physics.

a question after the slide 18, 19: why not to go faster ? We need a system to make technical decisions Form a collaboration  writing LOI F.A. Danevich Workshop on Double Beta Decay Search, SNU 16 Oct 2009