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/

m2 – : Summary

PDG 2000: 2002

SK atm.

SNO solar

: Consistent Checks to atm. amLAND : picks LMA for solar n

SK

SNO Salt Results …..Solar LMA Solution (before Sept 03)

Neutrino Mass Structures :

m2

※ absolute scale unknown

Solar

Normal Vs Inverted Hierachy ??

Quasi-Degenerate Vs Hierarchical ??

Atm.

TEXONO* CollaborationW.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. LaiChung Kuo Institute of Technology, Taipei, Taiwan

C.H. Hu, W.S. Kuo, T.R. YehInstitute of Nuclear Energy Research, Lungtan, Taiwan

H.Y. Liao, S.T. Lin, M.Z. WangNational Taiwan University, Taipei, Taiwan

F.K. LinNational Tsing Hua University, Hsinchu, Taiwan

Z.M. Fang, R.F. SuNuclear 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, ChinaJ.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. ChenNanjing University, Nanjing, ChinaY. An, D.Z. Liu, Q. Yue, Y.F. Zhu

Tsing Hua University, Beijing, ChinaC.Y. Chang, G.C.C. Chang

University of Maryland, Maryland, U.S.A.

Co-Prinicipal Investigators Ph.D. Students

HISTORYInitiate : Chang Chung-Yung 1996First Collab. Meeting/Official Start : October 1997First Paper : October 1998KS Reactor Experiment Installation : June 2000First Ph.D. : Liu Yan , July 2000First Physics Data Taking : June 2001.First Physics Results: Dec 2002.

TEXONO Overview

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) ]

Program:Kuo-Sheng Reactor Neutrino Laboratory

※ reactor : high flux of low energy electron anti-neutrinos

※ m0 anomalous properties & interactions

※ physics full of surprises , need intense -source

study/constraint new regime wherever experimentally accessible

explore possible new detection channels

R&D Projects

Kuo-Sheng Nuclear Power Plant

KS NPS-II : 2 cores 2.9 GW

KS Lab: 28 m from core#1

Kuo-Sheng Neutrino Laboratory High flux of e (also ….. e )

Modular Design : independent detector, electronics, shielding

high-Z target, large e

Improved detector performance:

good energy & spatial resolution,

low threshold, separation

Elaborate electronics+DAQ+control sys.

complete record of pulse shape + timing info.

Elaborate Shieldings

radon purge & 4cosmic veto

Kuo Sheng Reactor Neutrino Laboratory

Front Gate

Configuration: Modest yet Unique

Flexible Design: Allows different detectors conf. for different physics

Inner Target Volume

Front View (cosmic vetos, shieldings, control room …..)

KS Expt: Period I Detectors

FADC Readout

[16 ch., 20 MHz, 8 bit]

ULB-HPGe [1 kg] CsI(Tl) [46 kg]

Multi-Disks Array [600 Gb]

Kuo Sheng Reactor Neutrino Laboratory : First Res

ults

See Hau-Bin Li ‘s Talk

Citation in AIP’s Physics News Update #631-1 (2003).

Reactor (e) Sensitivities

Sensitivities

KS Physics Program : Period I & II

HPGe [1 kg] : : x2 more data from PRL improved background & analysis study e flux from reactor dominated by 51Cr : ~ 10-3 (prelim.)

study possible nuclear transitions

e.g. 73Ge* decays by 2’s separated by =4.6 s

CsI(Tl) [186 kg] : attempt measurement of Standard Model (ee-)

sinw at MeV range

Prototype ULE-HPGe [5 g] : threshold < 300 eV ~ 100 eV explore potentials on N coherent scattering & CDM

ee

Reactor Neutrino Interaction Cross-Sections

P3+: Coh. (N) < 1 keV

P1: MM (e) 1-100 keV

P2: SM (e) > 2 MeV

Reactor as e Source

Fission Material

Fission Products

Neutrons

odd-odd nuclei

Structural

materials of reactor

Electron capture or + decay ( neglected )

νe Emission

CapturedCaptured

Mostly rich in

neutrons

¯ Decay back to stable valley

Anti-neutrino Emisson

Tagging of 73Ge ½- 2 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 -induced nuclear transitions

CsI(Tl) Array : Highlights

40 cm length (longest commercial prod.)

Energy+3D info: 10% FWHM at 660 keV

(z) <2 cm @ E>250 keV

Detector Threshold ~ 20 keV

PSD for : > 99%

Intrinsic Purity : 238U/

232Th < 10

-12 g/g (equil.)

40K < 10

-10 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)

Region of Interest for SM e)

Z = 0 cm

Z =40 cm

208Tl

40K 137Cs

Venktesh Singh‘s Talk

“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 coherent scattering and Dark Matter searches

Hau-Bin Li & Qian Yue’s Talk

ULE-HPGe Prototype Results

PSD Cut

Threshold ~ 100 eV

Signal Band

Threshold < 100 eV

R&D Projects Explore New Detectors Scenarios (LE, 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 Pr

oject) Potential Merits:

Better PSD for separation than NaI(Tl)

Minimal passive materials

Large target mass possible (c/f em-calor. 40 tons)

KIMS Expt. :

200 kg CsI(Tl) for CDM

in S. Korea

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

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

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.

Mixed signal FADC Adapter Board

TEXONO/KS FADC for SPring8/LEPS

(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 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

identify research topics ……..

SL Typical Set-Up 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 overburdenContacts with International Team

IHEP’s 13 Proposal at Daya Bay near Hong Kong (Li Jin’s talk)

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 () Other analyses under way Period-II DAQ Improved HPGe Conf. 186 kg CsI(Tl) [(e) …] LEGe: study potentials for coh(N) Diversified R&D Program in parallel

TEXONO STATUS

Summary & Outlook

Neutrinos are important but strange objects history of physics full of surprises ! Strong evidenceS of massive ’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 !