Sun Kee Kim Seoul National University

Presentation on theme: "Sun Kee Kim Seoul National University"— Presentation transcript:

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

2 40Ca100MoO4 Reference sample CaMoO4 from the CARAT company
(Lviv, Ukraine)

3 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 % 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!

4 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

5 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 kgyr Ca100MoO4 T1/20  1026 yr kgyr Ca100MoO4 as low temperature bolometer NIMA 584 (2008) 334 F.A. Danevich Workshop on Double Beta Decay Search, SNU 16 Oct 2009

6

7 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> = eV by 90% CL 5 years, 100 kg 40Ca100MoO4 , further background reduction, resolution improvement: 7.0x1026 years -> 20 – 70 meV Fully covers inverted hierarchy

8 Other projected sensitivities and some theoretical predictions
Eth=10 keV (5 and 100 kg year) CaMoO4 CDMS 2008 SuperCDMS 25kg XENON Bottino et al XENON 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

9 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

10 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 cm, Pb cm, Cd 1-2 mm Polyethylene cm N2 flux to remove air (Rn) F.A. Danevich Workshop on Double Beta Decay Search, SNU 16 Oct 2009

11 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

12 100 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!

13 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

14 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.

15 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