TEXONO Research Program Overview: Status, Highlights, and Future Plans

1. Phoenix Park 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

2. 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)

3. 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

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

5. 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

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

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

8. Coverage in International Press

9. 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-nper fission ]

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

11. Nuclear material Fission products Structure material n n rich nuclei －decay EC EC n rich nuclei － decay Stable isotope even-even Stable isotope Electron neutrino emission electron anti-neutrino emission Electron Neutrinos @ Reactor (PRD 72, 2005) • Evaluate ne flux at standard reactors • Derive limits on mnand 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

12. 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

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

14. “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 [ mnsearch a by-product ] 5 g 4 X 5 g

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

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

17. 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

18. Yangyang (襄陽) Lab (Y2L) 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

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

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

21. 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)

22. 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]

24. 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

25. Summary & Outlook • TEXONO Collaboration:  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

26. 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 !