Highlights of the TEXONO Research Program : Status and Plans Overview of TEXONO Collaboration Research Program Kuo-Sheng Reactor Neutrino Laboratory Results Highlights Future Plans & Directions Henry T. Wong / 王子敬 Academia Sinica / 中央研究院 @ KIMS-TEXONO Joint Meeting Phoenix Park

Collaboration : TEXONO Collaboration Taiwan EXperiment On NeutrinO Collaboration : Taiwan (AS, INER, KSNPS, NTU,NCU,NCCU) China (IHEP, CIAE, THU, NJU, NKU) Turkey (METU) India (BHU) + Close Partnership (KIMS Collaboration in S. Korea)

 Poineering Efforts : “Zero-Background Experiment” ! KS Expt: 1st large-scale particle physics experiment in Taiwan TEXONO Coll. : 1st big research Coll. % Taiwan & China  ........ and now extending our presence to Korea, Turkey & India

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

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

Kuo Sheng Reactor Neutrino Laboratory : First Results on Neutrino Magnetic Moments (LST)

Coverage in International Press

Search of mn at low energy  high signal rate & robustness: mn>>SM [ decouple irreducible bkg  unknown sources ] T << En  ds/dT depends on total fn flux but NOT spectral shape [ flux well known : ~6 fission-n  ~1.2 238U capture-n per fission ]

Another notable result – First exploration of electron-neutrino production at reactors ….

Electron neutrino emission electron anti-neutrino emission Electron Neutrinos @ Reactor (PRD 72, 2005) Nuclear material Fission products n rich nuclei Stable isotope Structure material n －decay － decay EC even-even Electron neutrino emission electron anti-neutrino emission Evaluate ne flux at standard reactors Derive limits on mn and Gn for ne Explore ne flux enhancement in loaded reactor (e.g. with Cr) Study Potential applications : neNCC cross-section measurements, q13 Pu-production monitoring

Other on-going research program at KS: Measurement of neutrino-electron scattering cross-sections (i.e. sin2qW at MeV range) with CsI(Tl) crystals [MD] Search of reactor axions with HPGe Studies of neutrino induced nuclear transitions in 73Ge* Background measurement, understanding and suppression at reactor lab. [MD] Future Goal at KS: First observation of neutrino-nucleus coherent scattering [LST] Explore new detector energy down to 100 eV testing “ULEGe” prototypes at AS+KS+Y2L Expect ready for a major experiment with ~1 kg scale detector at 2007

CsI(Tl) Array (~200 kg) : s(ne) Data analysis under way…….. Single Crystal QL Vs QR (Raw Data) Region of Interest for SM s(ne) Z = 0 cm 208Tl 40K 137Cs Z =40 cm

“Ultra-Low-Energy” HPGe Prototype ULEGe – developed for soft X-rays detection ; easy & inexpensive & robust operation Prototype : (I) 5 g ; (II) 4 X 5 g ; (III) 10 g ; (IV) segmented 20 g threshold <100 eV after modest PSD [lowest achieved for bulk radiation detectors] study feasibilities for 1-kg-ish detector for nN coherent scattering and Dark Matter searches [ mn search a by-product ] 5 g 4 X 5 g

ULE-HPGe Prototype Results threshold ~100 eV , calibration by linear extrapolation from 1-6 keV PSD possible to suppress noise edge Threshold ~ 100 eV

Reactor Axions Analysis with HPGe data Like TEXONO HPGe Reactor core has intense M1 transitions : e.g. 7Li, 91Y, 97Nb etc. Signature : peak at transition energy at HPGe due to Primakoff conversion

Looking for n-induced 73Ge* Tagging of 73Ge ½- 2g transitions Event-by-Event background-free tag with PSD To do : Reactor ON/OFF analysis on the system ~1 s before/after the transition n-induced events signature: excess in the “ON+before” spectra

min. 700 m of rock overburden TEXONO  KIMS @ Y2L (LX) Install 5 g ULB-ULEGe at Y2L on January 2005 Study background and feasibility for CDM searches may evolve into a full-scale (1 kg) CDM experiment Yangyang (襄陽) Lab (Y2L) min. 700 m of rock overburden

Sensitivity Plot for CDM-WIMP search with 1 kg ULEGe at 100 eV threshold ………

Improved measurement of Quenching Factors in CsI(Tl) First direct verification of the optical model

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 (CIAE) 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 [NIM-B, 2006]  measure 40K~10-10 g/g in CsI (powder)  develop techniques for K in liquid scintillator Sensitivity goal : < 10-16 g/g Future :  87Rb …… [238U / 232Th series after Tandem upgrade]

Sonoluminescence Project (AS,NCU,CIAE) a frontier subject with possible surprises new directions : to explore subjects we do not know inter-disciplinary research  new research style and experience enriching 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 Achieved : devise method for UV detection [Ultrasonics, 2006] SonoLum Pulse

Summary & Outlook TEXONO Collaboration: Kuo-Sheng Neutrino Lab.:  Built-Up from Scratch & Maturing 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) & reactor ne

Diversified Program in Parallel Main Thrust on  ~200 kg CsI(Tl) [s(ne) …]  ULEGe: for scoh(nN) + CDM Present Focus of Collaborating Groups: AS :: mn  n-e S.  Coherent S.  SonoLum. CIAE :: AMS  SonoLum. THU :: CDM Search Reaching Out  Y2L @ Korea / Daya Bay Project (?) / Regional Framework TEXONO is a (modest) part of world neutrino physics community Tremendous Pleasure & Pressure !