1. 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

2. 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)

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

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  ~ U capture-n per fission ]

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

11. Electron neutrino emission electron anti-neutrino emission
Electron 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

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. 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

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 [ mn search 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. 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

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. min. 700 m of rock overburden
TEXONO  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

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 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 SPring8
TPC for 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 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 < g/g [NIM-B, 2006]
 measure 40K~10-10 g/g in CsI (powder)
 develop techniques for K in liquid scintillator
Sensitivity goal : < 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: 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

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
 Korea / Daya Bay Project (?) / Regional Framework
TEXONO is a (modest) part of world neutrino physics community
Tremendous Pleasure & Pressure !