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

@

Phoenix Park

KIMS-TEXONO Joint Meeting

TEXONO Collaboration

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)

Taiwan EXperiment On NeutrinO

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

Kuo-Sheng Nuclear Power Plant

KS NPS-II : 2 cores 2.9 GW

KS Lab: 28 m from core#1

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 …..)

R&D : Coh. (N)

T < 1 keV Results & More Data:

(e)

T ~ 1-100 keV

On-Going Data Taking & Analysis SM (e)

T > 2 MeV

Reactor Neutrino Interaction Cross-Sections

massquality Detector requirements

Kuo Sheng Reactor Neutrino Laboratory : First Results on Neutrino Magneti

c Moments (LST)

Coverage in International Press

Search of at low energy high signal rate & robustness:

>>SM [ decouple irreducible bkg unknown sources ] T << E d/dT depends on total flux but NOT spectral

shape [ flux well known : ~6 fission- ~1.2 238U capture-per fission ]

22

11)(2

ETmedT

de

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

Electron Neutrinos @ Reactor (PRD 72, 2005)

Nuclear material

Fission products

n rich nuclei

n rich nuclei

Stable isotopeStable isotope

Structure materialn

decay

decay

EC EC

even-even

Electron neutrino emission

electron anti-neutrino

emission

Evaluate e flux at standard reactors

Derive limits on and for e

Explore e flux enhancement in loaded reactor (e.g. with Cr)

Study Potential applications : eNCC cross-section meas

urements, 13 Pu-production monitoring

Other on-going research program at KS: Measurement of neutrino-electron scattering cross-sec

tions (i.e. sin2W 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 suppres

sion at reactor lab. [MD]

Future Goal at KS: First observation of neutrino-nucleus coherent scatte

ring [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

CsI(Tl) Array (~200 kg) : e)

Z =40 cm

Single Crystal QL Vs QR

(Raw Data)

Region of Interest for SM e)

Z = 0 cm

208Tl

40K 137Cs

Data analysis under way……..

“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 coherent scattering and Dark Matter searches [ search a by-product ]

5 g

4 X 5 g

ULE-HPGe Prototype Results

※ threshold ~100 eV , calibration by linear extrapolation from 1-6 keV

※ PSD possible to suppress noise edge

Threshold ~ 100 eV

Reactor Axions Analysis with HPGe data

Reactor core has intense M1 transitions : e.g. 7

Li, 91Y, 97Nb etc. Signature : peak at tra

nsition energy at HPGe due to Primakoff conversion

Like TEXONO HPGe

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/after the transition

-induced events signature: excess in the “ON+before” spectra

Looking for -induced 73Ge*

Yangyang ( 襄陽 ) Lab (Y2L)min. 700 m of rock overburden

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

TEXONO KIMS @ Y2L (LX)

Sensitivity Plot for CDM-WIMP search with

1 kg ULEGe at 100 eV threshold ………

Improved measurement of Quenching Factors in CsI(Tl)First direct verification of the optical model

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 (CIAE)

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 [NIM-B, 2006]

measure 40K~10-10 g/g in CsI (powder)

develop techniques for K in liquid scintillator

Sensitivity goal : < 10-16 g/g

Future : 87Rb …… [238U / 232Th series after Tandem upgrade]

Sonoluminescence Project (AS,NCU,CIAE)

SonoLum Pulse

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]

TEXONO Collaboration: 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 & reactor e

Summary & Outlook

Diversified Program in Parallel Main Thrust on ~200 kg CsI(Tl) [(e) …] ULEGe: for coh(N) + CDM Present Focus of Collaborating Groups: AS :: -e S. Coherent S. SonoLu

m.CIAE :: AMS SonoLum.

THU :: CDM Search Reaching Out Y2L @ Korea / Daya Bay Project (?) / Regional Framework

TEXONO is a (modest) part of world neutrino physics community

Tremendous Pleasure & Pressure !