TEXONO Research Program on Low Energy
Neutrino and Astroparticle Physics
 Recent Status of Neutrino Physics
TEXONO Collaboration : Overview
 Kuo-Sheng(國聖) Reactor Neutrino Laboratory
※ Facilities
※ Research Topics
 R&D Program
Henry T. Wong / 王子敬
Academia Sinica /中央研究院
@ Yong Pyong / 龍平
*
Taiwan EXperiement On NeutrinO
http://hepmail.phys.sinica.edu.tw/~texono/
Dm2 –  : Summary
PDG 2000:
2002
SK atm. n
SNO solar n
KamLAND : picks LMA for solar n
K2K : Consistent Checks to atm. n
SK
Solar LMA Solution (before Sept 03)
+ SNO Salt Results …..
Neutrino Mass Structures :
Dm2
Normal Vs Inverted Hierachy ??
Quasi-Degenerate Vs Hierarchical ??
Atm. n
Solar n
※ absolute scale unknown
*
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
Initiate : Chang Chung-Yung 1996
Nanjing University, Nanjing, China
First Collab. Meeting/Official Start :
Y. An, D.Z. Liu, Q. Yue, Y.F. Zhu
October 1997
Tsing Hua University, Beijing, China
First Paper : October 1998
C.Y. Chang, G.C.C. Chang
KS Reactor Experiment Installation : June
University of Maryland, Maryland, U.S.A.
HISTORY
Co-Prinicipal Investigators
Ph.D. Students
2000
First Ph.D. : Liu Yan , July 2000
First Physics Data Taking : June 2001.
First Physics Results: Dec 2002.
Program:
TEXONO Overview
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) ]

Kuo-Sheng Nuclear Power Plant
KS NPS-II : 2 cores  2.9 GW
KS n Lab: 28 m from core#1
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
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
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]
Kuo Sheng Reactor Neutrino
Laboratory : First Results
 See Hau-Bin Li ‘s Talk
Citation in AIP’s Physics News Update #631-1 (2003).
Reactor mn(ne) Sensitivities
Gn Sensitivities
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 : n e n e ~ 10-3 (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-)
 sin2w at MeV range
Prototype ULE-HPGe [5 g] :
 threshold < 300 eV  ~ 100 eV
 explore potentials on nN coherent scattering & CDM
Reactor Neutrino Interaction Cross-Sections
P2: SM
(ne) > 2
MeV
P1:
P3+: Coh.
MM (ne)
(nN) <
1-100 keV
1 keV
Reactor as ne Source
Fission Material
Fission
Products
Mostly
rich in
neutrons
¯ Decay back to  stable
valley
Anti-neutrino
Emisson
Neutrons
Captured
Captured
Structura
l
materials
of reactor
odd-odd
nuclei
Electron capture or +
decay ( neglected )
νe Emission
Tagging of 73Ge ½- 2g transitions:
Event-by-Event backgroundfree 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
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 : 
238
232
U/ Th < 10
 K < 10
40
-10
-12
g/g (equil.)
g/g
cosmic muon events on-site @ 46 kg target
Full Detector:
 186 kg
target on-site for Period-II
 DAQ with large dynamic range
Period-2 CsI(Tl) Array : 186 kg, 93 crystals
Single Crystal QL Vs QR (Raw Data)
Z = 0 cm
 Venktesh Singh‘s Talk
Z =40 cm
208Tl
137Cs
40K
Region of Interest for SM s(ne)
“Ultra-Low-Energy” HPGe Prototype
mass 5 g ; can be constructed in multi-array form
threshold <100 eV after modest PSD
background measurement on-site Nov 03
study appl. in nN coherent scattering and Dark Matter searches
 Hau-Bin Li & Qian Yue’s Talk
ULE-HPGe Prototype Results
PSD Cut
Threshold
~ 100 eV
Threshold < 100 eV
Signal Band
R&D Projects
 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 Experiment @ Korea by KIMS Coll.
 Upgrading FADCs (+ FPGA etc. capabilities…..)
 for LEPS @ SPring8
 Trace Radio-purity with AMS
( Accelerator Mass Spectrometry)
 1st goal : sensitivity of 10-14 g/g in 40K
 Sono-Luminescence Project (inter-disciplinary)
CsI(Tl) for CDM Searches
(Feasibility Studies : TEXONO-CosPa Project)
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. :
 200 kg CsI(Tl) for CDM
in S. Korea
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
 Based
at AMS facilities @CIAE with 13 MV Tandem
 Potential Merits:
 small samples, quick
 versatile on sample choice
 sensitive to a/ 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
 measure 40K~10-10 g/g in CsI (powder)
Sensitivity goal : 10-14 g/g
 Future :  different bases e.g. liquid scintillator
 87Rb …… [238U / 232Th series after Tandem upgrade]
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
SL Typical Set-Up
 identify research topics ……..
SL Typical Cycle
SonoLum Pulse
Also ……….
 Geographically possible for medium
baseline experiment for “13” :
 Easy reach from city
 Access to Plant established
 Road tunnel at 2 km
 100 m rock overburden
Contacts with International Team
 IHEP’s 13 Proposal at Daya Bay near
Hong Kong (Li Jin’s talk)
TEXONO STATUS
 TEXONO Collaboration:
 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
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 !