1. *Taiwan EXperiement On NeutrinO (台灣微中子實驗)
Low Energy Neutrino Physics at the Kuo-Sheng Reactor Neutrino Laboratory in Taiwan
TEXONO Collaboration : Overview
Kuo-Sheng(國聖) Reactor Neutrino Laboratory
※ Facilities
 Magnetic Moments Results (See H.B. Li’s Talk)
※ Research Topics
R&D Program
Henry T. Wong / 王子敬
Academia Sinica /中央研究院
@ CosPA 2003
*Taiwan EXperiement On NeutrinO (台灣微中子實驗)
Home

2. 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.
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.

3. Poineering Efforts : “Zero-Background Experiment” !
TEXONO Overview
Program:
Kuo-Sheng Reactor Neutrino Laboratory
※ reactor : high flux of low energy electron anti-neutrinos
※ mn0  anomalous n properties & interactions
※ n physics full of surprises , need intense n-source
 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) ]

4. 

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

6. Kuo-Sheng Neutrino Laboratory
High flux of ne (also ….. ne )
Modular Design : independent detector, electronics, shielding
high-Z target, large re
Improved detector performance:
 good energy & spatial resolution,
 low threshold, a/g separation
Elaborate electronics+DAQ+control sys.
 complete record of pulse shape + timing info.
Elaborate Shieldings
 radon purge & 4p cosmic veto

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. 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]

9. Kuo Sheng Reactor Neutrino Laboratory : First Results
 See Hau-Bin Li ‘s Talk
Citation in AIP’s Physics News Update #631-1 (2003).

10. Reactor mn(ne) Sensitivities
Gn Sensitivities

11. KS Physics Program : Period I & II
HPGe [1 kg] :
mn + Gn : x2 more data from PRL
improved background & analysis
study ne flux from reactor
dominated by 51Cr : ~ (prelim.)
study possible nuclear transitions
e.g. 73Ge* decays by 2g’s separated by t1/2=4.6 ms
CsI(Tl) [186 kg] :
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

12. Reactor Neutrino Interaction Cross-Sections
P2: SM (ne) > 2 MeV
P1: MM (ne) keV
P3+: Coh. (nN) < 1 keV

13. Reactor as ne Source Fission Material Fission Products Neutrons
odd-odd nuclei
Structural materials of reactor
Electron capture or + decay ( neglected )
νe Emission
Captured
Mostly rich in neutrons
¯ Decay back to  stable valley
Anti-neutrino Emisson

14. 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 the transition
To look for : possible n-induced nuclear transitions

15. CsI(Tl) Array : Highlights
40 cm length (longest commercial prod.)
Energy+3D info:  10% FWHM at 660 keV
 s(z) <2 cm @ E>250 keV
Detector Threshold ~ 20 keV
PSD for g/a : > 99%
Intrinsic Purity :  238U/232Th < g/g (equil.)
 40K < g/g
cosmic muon events 46 kg target
Full Detector:
186 kg target on-site for Period-II
DAQ with large dynamic range

16. Period-2 CsI(Tl) Array : 186 kg, 93 crystals
Single Crystal QL Vs QR (Raw Data)
Z = 0 cm
Z =40 cm
208Tl
40K
137Cs
Region of Interest for SM s(ne)

17. “Ultra-Low-Energy” HPGe Prototype
mass 5 g ; can be constructed in multi-array form
55Fe+Ti back-scattered Spectra : noise edge at 200 eV
threshold <100 eV after modest PSD
background measurement on-site Nov 03
study appl. in nN coherent scattering and Dark Matter searches

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

19. R&D Projects Upgrading FADCs (+ FPGA etc. capabilities…..)
Explore New Detectors Scenarios (LEn, CDM …)
 other crystal scintillators
 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)

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
a frontier subject with possible surprises
new directions : to explore subjects we do not know
Table-top experiments, pursue-able in several labs
 balance the other big & long time-scale projects
 use HEP approaches
Status :
 produce steady SL
 integrate DAQ
 study physics
 identify research topics ……..
SL Typical Cycle
SL Typical Set-Up

24. SonoLum Pulse

25. Also ………. Road tunnel at 2 km 100 m rock overburden
Geographically possible for medium baseline experiment for “q13” :
Easy reach from city
Access to Plant established
Road tunnel at 2 km
100 m rock overburden
Contacts with International Team

26. TEXONO STATUS TEXONO Collaboration: Kuo-Sheng Neutrino Lab.:
 Built-Up and 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 analyses under way
Period-II DAQ  Improved HPGe Conf.
 186 kg CsI(Tl) [s(ne) …]
 LEGe: study potentials for scoh(nN)
Diversified R&D Program in parallel

27. Summary & Outlook Neutrinos are important but strange objects
history of n physics full of surprises !
Strong evidenceS of massive n’s & finite mixings
Physics Beyond the Standard Model !
More experiments & projects coming up
EVEN MORE EXCITEMENT !
TEXONO is also a (modest) part of it
Tremendous Pleasure & Pressure !