1. 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

2. Experimental Particle Physics in Taiwan
…… started late 80’s , with existing nuclear physics/engineering programs
Academia Sinica (中央研究院) :
(opto-electronics ….)
Shuttle & Station (space electronics ….)
TEXONO Program on Neutrino Physics in Taiwan [LOCALLY based and led]
(fast electronics, analysis ….)
(GRID computing, opto-electronics …….)
National Taiwan University (台灣大學) :
(EFCalo, analysis …)
National Central University (中央大學) :
(Si-detectors …..)
(Si-detectors…..)
 Satellite Institutes
 closely-connected Theory, Astronomy , Space Program, Sync. Rad. … communities

3. 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.

4. 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) ]

5. 

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

7. 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

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

9. 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]

10. Kuo Sheng Reactor Neutrino Laboratory : First Results

11. 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

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

13. Reactor mn(ne) Sensitivities
Gn Sensitivities

14. 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

15. 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 ~ keV

16. “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

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

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

19. 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 Korea by KIMS Coll.
Upgrading FADCs (+ FPGA etc. capabilities…..)
 for SPring8
Trace Radio-purity with AMS ( Accelerator Mass Spectrometry)
 1st goal : sensitivity of g/g in 40K
Sono-Luminescence Project (inter-disciplinary)
Completed
On-Going
Completed
Completed
On-Going
On-Going

20. 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. :
 kg CsI(Tl) for CDM
in S. Korea

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
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
 measure 40K~10-10 g/g in CsI (powder)
Sensitivity goal : g/g
Future :  different bases e.g. liquid scintillator
 87Rb …… [238U / 232Th series after Tandem upgrade]

23. 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

24. SonoLum Pulse

25. min. 700 m of rock overburden
TEXONO-KIMS Connections ………
KIMS: funded Dark Matter program with underground 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

26. 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

27. 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
 Korea / Daya Bay Project (?) / Regional Framework (?)
 welcome new collaborators & happy to explore other scenario
TEXONO is (a modest) part of world neutrino physics community