The TEXONO Program in Neutrino and Astroparticle Physics: Overview and Plans V. Singh (On behalf of the TEXONO Collaboration) Institute of Physics Academia Sinica, Taipei 11529 Taiwan u Introduction u Kuo-Sheng Period – I Program - CsI Array, photos, performance etc. u Kuo-Sheng Period – II Program - New HPGe configurations + first results, Period I HE spectra and SM curve - CsI Array, photos, performance, background etc. u R & D Programs u Summary
TEXONO: Personnel Highlights 2002-03 l Ph.D. for Li Hau-Bin, NTU (June 2002) on neutrino magnetic moment analysis l Ph.D. due in 2003 - Yue Qian, IHEP, on Dark Matter Feasibility Studies - Xin Biao, CIAE, on reactor electron neutrino calculation and analysis l New Ph.D. student : Lin Shin-Ted, NTU l Postdoc Chen Chin-Ping : - faculty appointment at Peking U. l Beijing Tsing Hua University joined - participation of M.Sc students l under discussion : - joining of a Mexican cosmic-ray group
Kuo-Sheng Nuclear Power Plant KS NPS-II : 2 cores X 2.9 GW KS n Lab: 28 m from core#1 108 m from core#2 Overburden ~ 10 m concrete Flux=5.6*10^12/cm^2 s
Kuo-Shung Expt.: Period I (June01-April02) Detectors ULB-HPGe [1 kg] CsI(Tl) [46 kg] FADC Readout [16 ch., 20 MHz, 8 bit] Multi-Disks Array [600 Gb]
Kuo-Shung Period – I Ge : Results Limits On : (Submitted in PRL) Based on 196/52 days of Reactor ON/OFF data No anomalous structures or residuals Det. Threshold 5 KeV Bkg. ~1/KeV-Kg-day above 12 KeV Limits On : (Submitted in PRL) mn < 1.3 (1.0) X 10-10 mB @ 90(68)% C.L. Li H.B. Talk Feb.,14, 2003
CsI(Tl) Array/P-I : Highlights & Technical Run 40 cm length (longest commercial prod.) Energy+3D info: 10% FWHM at 660 keV s(z) <2 cm @ E>250 keV Detector Threshold ~ 20 keV PSD for g/a : > 99% Intrinsic Purity : 238U/232Th < 10-12 g/g (equil.) 40K < 10-10 g/g
Radon Purge Plastic Bag
Selected Photos – Period - II Installation – HPGe
Improvement in Period- II :Ge 4p anti-Compton coverage improved inner shielding Aim of analysis threshold: ~ 5 keV study “ultra-low” energy Ge prototype [threshold : 200-300 eV] Event/KeV/day in 06-08 KeV = 3.47 P-II = 7.10 P-I Event/KeV/day in 20-40 KeV = 1.39 P-II = 1.70 P-I
Selected Photos – Period - II Installation – CsI(Tl) Array
Shielding inside the Target Volume June 2001 (For Period – I) Jan. 2003 (For Period – II)
Steady Increment of CsI(Tl) Channels From 14 to 180+ Better Shielding Improved Results Proto-type Phase – I Phase – II
Period-2 CsI(Tl) Array : 186 kg, 93 crystals Single Crystal QL Vs QR 137 Cs 40 K
KS/P2: 93-Element CsI(Tl) Array (to be optimized)
Reactor Neutrino Interaction Cross-Sections P-III+: Coh. (nN) < 1 keV P-II: SM (ne) > 2 MeV "Standard Model n - e scattering" - related to fundamental electroweak parameters Sin**2 (qw) - observed but NOT measured at MeV range - detection channel for many solar neutrino experiment P-I: MM (ne) 1-100 keV
R&D Projects Upgrading FADCs Explore New Detectors Scenarios loaded crystal scintillator (GSO, YbAG, LSO …..) [Published in NIM A 432, 111 (1999)] ultra low energy HPGe [ O(100 eV) threshold ] CsI(Tl) for Dark Matter Searches Upgrading FADCs Trace Radio-purity with AMS ( Accelerator Mass Spectrometry) Sono-Luminescence Project (fermenting ……..) Close Contact with : CsI(Tl) CDM search @ Korea JHFBeijing LBL n project @ IHEP Ultra HE (1015 eV) n Telescope @ NTU
CsI(Tl) for CDM Searches Potential Merits: Better PSD for g/a separation than NaI(Tl) Minimal passive materials Large target mass possible (c/f em-calor. 40 tons) Highlights of R&D Program: Quenching Factor measurements with neutron beam lowest threshold data [Published in PL B and NIM (2002)] 1st direct measurement of diff. cross section in heavy nuclei PSD studies with Neural Net. & Max. Likelihood improve conventional methods N KIMS Expt. (apprd.) : 200 kg CsI(Tl) for CDM in S. Korea
TEXONO/KS FADC for SPring8 40 MHz ; 12 bit ; 32 ch/module @ 9 U VME [ c/f KS FADC : 20 MHz ; 8 bit ; 16 ch/module ] On-board processing with FPGA 1000 channels to be used in TPC in LEPS Expt. @ SPring8 by End 2002. TPC for LEPS @ SPring8 Mixed signal FADC Adapter Board 40 MHz sampling rate. 10 bits resolution with 2Vp-p dynamic range. Clock distribution with Phase Lock Loop circuit. On Board digital signal delay and Real-Time ZERO-Suppression. High capacity First In First Out Memory. Easy to use with high density connector. Prototype Measurements : (cosmic muon)
Trace Radio-purity with AMS Based at AMS facilities @CIAE with 13 MV Tandem Potential Merits: small samples, quick versatile on sample choice sensitive to a/b emitters sensitive to stable isotope & extrapolate (e.g. 39K) >103 improvements over ICP-MS [.. once prescriptions are known. ] Status : demonstrate 129I/127I < 10-12 g/g measure 40K~10-10 g/g in CsI (powder) Sensitivity goal : 10-14 g/g [Published in NIM A479, 498(2002)] Future : different bases e.g. liquid scintillator 87Rb …… [238U / 232Th series after Tandem upgrade]
Summary TEXONO Collaboration: Kuo-Sheng Neutrino Lab.: Built-Up and Growing Kuo-Sheng Neutrino Lab.: Established & Operational ※Modular & Flexible Design Physics Data Taking since June 01-April02 ※Unique HPGe Low Energy Data ※ Bkg Level ~ Underground CDM Expt. Results on mn (Gn) ※ Other speculative analyses under way ※ Submitted in PRL Period-2 DAQ Improved HPGe Conf. Commissioning 186 kg CsI(Tl) [+ s(ne) …] Diversified R&D Program in parallel
Full TEXONO* Collaboration Author List W.C. Chang¶, C.P. Chen, K.C. Cheng, H.C. Hsu, F.S. Lee, S.C. Lee, S.T. Lin, D.S. Su, V. Singh, P.K. Teng, W.S. Tse¶, H.T.K. Wong†, C.S. Wu, S.C. Wu Academia Sinica, Taipei, Taiwan W.P. Lai Chung Kuo Institute of Technology, Taipei, Taiwan C.H. Hu, J.M. Huang, W.S. Kuo, T.R. Yeh Institute of Nuclear Energy Research, Lungtan, Taiwan H.B. Li, M.Z. Wang¶ National Taiwan University, Taipei, Taiwan J.H. Chao, J.H. Liang National Tsing Hua University, Hsinchu, Taiwan Z.M. Fang, R.F. Su Nuclear Power Station II, Kuosheng, Taiwan M. He, S. Jiang, L. Hou, H.Q. Tang, B. Xin, Z.Y. Zhou¶ Institute of Atomic Energy, Beijing, China J. Li†, Y. Liu, Z.P. Mao, J. Nie, J.F. Qiu, H.Y. Sheng, P.L. Wang, X.W. Wang, Q. Yue, D.X. Zhao, J.W. Zhao, P.P. Zhao, S.Q. Zhao, B.A. Zhuang Institute of High Energy Physics, Beijing, China Z.S. Liu, Z.Y. Zhang Institute of Radiation Protection, Taiyuan, China T.Y. Chen Nanjing University, Nanjing, China J.P. Cheng, D.Z. Liu Tsing Hua University, Beijing, China C.Y. Chang, G.C.C. Chang† University of Maryland, Maryland, U.S.A. † Co-Prinicipal Investigators ¶ Project Leaders Ph.D. Students *Taiwan EXperiement On NeutrinO Home Page @ http://hepmail.phys.sinica.edu.tw/~texono/ HISTORY Initiate : Chang Chung-Yung 1996 First Collab. Meeting/Official Start : October 1997 First Paper : October 1998 KS Reactor Experiment Installation : June 2000 First Ph.D. : Liu Yan , July 2000 First Physics Data Taking : June 2001.