TEXONO Research Program on Low Energy Neutrino and Astroparticle Physics Overview : Experimental Particle Physicsin Taiwan & TEXONO Collaboration Kuo-Sheng(國聖) Reactor Neutrino Laboratory ※ Facilities ※ Research Topics R&D Program Summary & Outlook Henry T. Wong / 王子敬 Academia Sinica /中央研究院 @ APN04 *Taiwan EXperiement On NeutrinO http://hepmail.phys.sinica.edu.tw/~texono/

Experimental Particle Physics in Taiwan …… started late 80’s , with existing nuclear physics/engineering programs Academia Sinica (中央研究院) : CDF@Tevatron@Fermilab (opto-electronics ….) AMS@Space Shuttle & Station (space electronics ….) TEXONO Program on Neutrino Physics in Taiwan [LOCALLY based and led] LEPS@SPring8 (fast electronics, analysis ….) ATLAS@LHC@CERN (GRID computing, opto-electronics …….) National Taiwan University (台灣大學) : Belle@KEKB@KEK (EFCalo, analysis …) CMS@LHC@CERN National Central University (中央大學) : L3@LEP@CERN PHOBOS@RHIC@BNL (Si-detectors …..) CMS@LHC@CERN (Si-detectors…..)  Satellite Institutes  closely-connected Theory, Astronomy , Space Program, Sync. Rad. … communities

TEXONO* Collaboration W.C. Chang, K.C. Cheng, M.H. Chou, H.C. Hsu, C.H. Iong, G.C.Jon, F.S. Lee, S.C.Lee, H.B. Li, V. Singh, D.S. Su, P.K.Teng, H.T.K.Wong,  S.C. Wu Academia Sinica, Taipei, Taiwan W.P. Lai Chung Kuo Institute of Technology, Taipei, Taiwan C.H. Hu, W.S. Kuo, T.R. Yeh Institute of Nuclear Energy Research, Lungtan, Taiwan H.Y. Liao, S.T. Lin, M.Z. Wang National Taiwan University, Taipei, Taiwan F.K. Lin National Tsing Hua University, Hsinchu, Taiwan Z.M. Fang, R.F. Su Nuclear Power Station II, Kuosheng, Taiwan J. Bao, K.J. Dong, S. Jiang, L. Hou, Y.H. Liu, H.Q. Tang, B. Xin, Z.Y. Zhou Institute of Atomic Energy, Beijing, China J.Li, Y. Liu, J. Nie, Z.P.Mao, J.F.Qiu, H.Y.Sheng, P.L.Wang, X.W. Wang, D.X.Zhao, P.P.Zhao, B.A.Zhuang 　 Institute of High Energy Physics, Beijing, China J.Q. Lu, T.Y. Chen Nanjing University, Nanjing, China Y. An, D.Z. Liu, Q. Yue, Y.F. Zhu Tsing Hua University, Beijing, China C.Y. Chang, G.C.C. Chang University of Maryland, Maryland, U.S.A. M. Deniz, M. Zeyrek Middle East Technical University, Turkey Co-Prinicipal Investigators Ph.D. Students 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. First Physics Results: Dec 2002.

Poineering Efforts : “Zero-Background Experiment” ! TEXONO Overview Program: Kuo-Sheng Reactor Neutrino Laboratory ※ oscillation expts.  mn0  anomalous n properties & interactions ※ n physics full of surprises , need intense n-source ※ reactor : high flux of low energy electron anti-neutrinos  study/constraint new regime wherever experimentally accessible  explore possible new detection channels R&D Projects Poineering Efforts : “Zero-Background Experiment” ! KS Expt: 1st large-scale particle physics experiment in Taiwan TEXONO Coll. : 1st big research Coll. % Taiwan & China [feature report in Science, Vol. 300, 1074 (2003) ]

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Kuo-Sheng Nuclear Power Plant KS NPS-II : 2 cores  2.9 GW KS n Lab: 28 m from core#1

Kuo Sheng Reactor Neutrino Laboratory Front Gate Front View (cosmic vetos, shieldings, control room …..) Configuration: Modest yet Unique Flexible Design: Allows different detectors conf. for different physics Inner Target Volume

ULB-HPGe + Anti-Comptons KS Expt. : Period I-III Configuration Shielding & Veto [one side] ULB-HPGe + Anti-Comptons CsI(Tl) Array (200 kg)

KS Expt: Period I Detectors ULB-HPGe [1 kg] CsI(Tl) [46 kg] FADC Readout [16 ch., 20 MHz, 8 bit] Multi-Disks Array [600 Gb]

Kuo Sheng Reactor Neutrino Laboratory : First Results

Motivations fundamental neutrino properties & interactions ; a channel to differentiate Dirac/Majorana neutrinos (nD/nM) look for surprises and/or constrain parameter space with future precision oscillation data study 1/T spectral shape in n-e scattering, T is electron recoil energy Related to neutrino radiative decays

TEXONO data (4712/1250 hours ON/OFF) [PRL 90, 2003] comparable bkg level to underground CDM experiment at 10-20 keV : ~ 1 day-1keV-1kg-1 (cpd) analysis threshold 12 keV No excess of counts ON/OFF comparison Limit: mn(ne) < 1.3 X 10-10 mB (90% CL) more data/improvement to get to sensitivity range mn(ne) 1.0 X 10-10 mB

Reactor mn(ne) Sensitivities Gn Sensitivities

KS Physics Program : Periods I & II & III HPGe [1 kg] : mn + Gn : x2 more data from PRL improved background & analysis study ne flux from reactor [B. Xin’s talk] study possible nuclear transitions e.g. 73Ge* decays by 2g’s separated by t1/2=4.6 ms Possible reactor axion search CsI(Tl) [186 kg] : [V.Singh’s talk] attempt measurement of Standard Model s(nee-)  sin2qw at MeV range Prototype ULE-HPGe [5 g] : threshold < 300 eV  ~ 100 eV explore potentials on nN coherent scattering & CDM

Reactor Neutrino Interaction Cross-Sections On-Going Data Taking: SM s(ne) T > 2 MeV R&D : Coh. (nN) T < 1 keV Results & More Data: mn(ne) T ~ 1-100 keV

“Ultra-Low-Energy” HPGe Prototype mass 5 g ; can be constructed in multi-array form threshold <100 eV after modest PSD (lowest achieved for bulk radiation detectors) background measurement on-site Nov 03 study appl. in nN coherent scattering and Dark Matter searches

ULE-HPGe Prototype Results PSD Cut Threshold ~ 100 eV Threshold < 100 eV Signal Band

Sensitivity Plot for CDM-WIMP search with 1 kg ULEGe at 100 eV threshold ……… [Q. Yue’s talk]

R&D Projects Upgrading FADCs (+ FPGA etc. capabilities…..) Explore New Detectors Scenarios (LEn, CDM …)  other crystal scintillators (GSO …)  ultra low energy HPGe [ O(100 eV) threshold ] Feasibility Studies on CsI(Tl) for Dark Matter Searches  Approved Experiment @ Korea by KIMS Coll. Upgrading FADCs (+ FPGA etc. capabilities…..)  for LEPS @ SPring8 Trace Radio-purity with AMS ( Accelerator Mass Spectrometry)  1st goal : sensitivity of 10-14 g/g in 40K Sono-Luminescence Project (inter-disciplinary) Completed On-Going Completed Completed On-Going On-Going

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 1st direct measurement of diff. cross section in heavy nuclei PSD studies with Neural Net. & Max. Likelihood  improve conventional methods N KIMS Expt. :  200 kg CsI(Tl) for CDM in S. Korea

TEXONO/KS FADC for SPring8/LEPS 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 used in TPC in LEPS Expt. @ SPring8 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. (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 Future :  different bases e.g. liquid scintillator  87Rb …… [238U / 232Th series after Tandem upgrade]

Sonoluminescence Project (AS,CIAE,THU….) a frontier subject with possible surprises new directions : to explore subjects we do not know inter-disciplinary research  a testing ground from HEP group future possibility Table-top experiments, pursue-able in several labs  balance the other big & long time-scale projects  use HEP approaches Focus :  understand physics mechanism  emissions of high energy radiations SonoLum Pulse

SonoLum Pulse

min. 700 m of rock overburden TEXONO-KIMS Connections ……… KIMS: funded Dark Matter program with underground facility @ Y2L in Korea [Y.D. Kim’s talk] bring LE-HPGe to Y2L for measurement 04/05 [led by THU team]  background below 1 keV, CDM searches may evolve into a full-scale (1 kg) CDM experiment may broaden framework in the future (regular joint meetings ; sharing of know-how ….) Yangyang (襄陽) Lab (Y2L) min. 700 m of rock overburden

Li Jin’s talk ……….. Possibilities for Reactor q13 ……… IHEP’s q13 Proposal at Daya Bay near Hong Kong  More Powerful Reactor Complex  More overburden possible from mountains  Tunnel Digging Cost Less in China

Summary & Outlook ※ Current Research Focus at : TEXONO Collaboration:  Built-Up & Growing Kuo-Sheng Neutrino Lab.:  Established & Operational ※ Modular & Flexible Design  Physics Data Taking since June 01 ※ Unique HPGe Low Energy Data ※ Bkg Level ~ Underground CDM Expt. Results published on mn (Gn)  Other DAQ+analyses under way Diversified R&D Program in parallel ※ Current Research Focus at : mn (Gn) & s(n-e ) & scoh(nN) & SonoLum. & CDM & AMS Reaching Out  Y2L @ Korea / Daya Bay Project (?) / Regional Framework (?)  welcome new collaborators & happy to explore other scenario TEXONO is (a modest) part of world neutrino physics community