Basic Energy Sciences Neutron & Photon Detector Workshop

August 1-3, 2012 Holiday Inn Gaithersburg, USA

Development of Scintillator Detectors at J-PARC/MLF

J-PARC, JAEA

Kazuhiko Soyama

Contents

1. J-PARC, High intensity pulsed neutron source

2. Scientific demands and neutron detectors

3. State of the art

4. J-PARC activity

Bird’s eye photo in January of 2008

J-PARC Facility (KEK/JAEA）

Linac

North to South

Accelerators

50 GeV Synchrotron

3 GeV Synchrotron

JRR-3

Materials and Life Sciences Facility

Hadrons Science Facility

Neutrino experimental facility Experimental Facilities

Superconducting magnets for the neutrino beamline

50GeV Synchrotron（1600 ｍ）

3GeV Synchrotron (350ｍ） Linac（330ｍ）

#1 Hall

#1 Hall

Materials and Life Experimental Facility

Mercury Target for Neutrons

Neutron Source

#2 Hall

proton（Δt~１mｓ）

accelerator Spallation process

moderator contains hydrogen atoms

mass of hydrogen ~ mass of neutron

Cd and Ag-In-Cd absorb thermal

neutrons

Moderation of neutron Reduce neutron energy from MeV to meV

Hg target

Moderator

（20K Hydrogen）

0.7ms

Be reflector

Decoupled moderator

Coupled moderator

High intensity,

Low resolution

Decoupled poisoned

moderator Cd

poisoning

plate

Ag-In-Cd

decoupler

Medium

resolution

High

resolution

1014

1015

1016

1017

10-4

10-3

10-2

10-1

100

101

Puls

e P

eak Inte

nsity(n

/cm

2/s/sr/

eV

/puls

e)

Coupled

Decoupled

Hg TargetBe reflector1MW 25Hz

Poisoned(center)

ILL cold (56 MW)

Energy (eV)

100 times

Time Averaged Intensity (for CM) :1/4 of ILL’s Cold source

Pulse Peak Intensity (for CM) ：~100 of ILL’s Cold source

PM

Proton

BL-22 Imaging

BL-23 Chopper

Hg target

4.610+8 n/sec/cm2

0.6510+8 n/sec/cm2

0.9510+8 n/sec/cm2

92 msec

Pulse Width in FWHM at 10meV

Time-integrated Thermal Neutron Flux

33 msec

22 msec

CM DM

Flux values 10m from the moderator

ANNRI (Tokyo Tech. U., JAEA, Hokkaido U.)

iBIX (Ibaraki Pref.)

DNA (JAEA)

4SEASONS （JAEA, KEK, Tohoku U.）

NOVA （NEDO, KEK）

iMATERIA (Ibaraki Pref.)

TAKUMI (JAEA)

NOBORU (JAEA)

NOP (KEK) SuperHRPD (KEK)

PLANET (U. of Tokyo, JAEA)

HRC (KEK)

SOFIA (KEK)

TAIKAN (JAEA)

AMATERAS (JAEA)

SHARAKU(JAEA) SENJU (JAEA)

Neutron Instruments at Materials and Life Science Facility SPICA (KEK)

Hydrogen-bonds and hydration structure in biological macromolecules as proteins have been thought to play an important role in the stability of 3-dimensional structure and reaction mechanism. The demand on the positional information of hydrogen involved in a protein molecule has been increasing recently. The demand on neutron structure biology in the current life science field has continuously increased. But the present instruments’s performance is not sufficient considering the international competition in biological science and appli- cation to drug design and so on.

Molecular recognition and chemical reaction

in the protein field

drug design

Principle of protein structure

Surface area : 1.1 m2 (at L2=0.3m)

Position resolution 1 1 mm

Detection efficiency : > 20% @ 1Å

Pulse pair resolution : 1 msec

Small dead area

Low gamma sensitivity

Low cost

Detector requirement of single crystal diffractometer for biologically important materials

Required detector performance

250 ×250 mm

Gas, MWPC Delay line

2.5 ×2.5mm

70% (3Å), 35% (1Å)

104 / sec

Ordela Model2250

http://www.ordela.com/ about/index.htm

ISIS 2D Fibre Coded

192 ×192 mm

Sci., ZnS/LiF Fibre Coded 3×3 mm

20% (1Å)

105 / sec/unit

http://jra2.neutron-eu.net/FILES/ Nigel_Rhodes.pdf

The New Ceramic Scintillator developed for J-PARC F - A Key Technology to High Intensity Pulsed Neutron Science

ZnS/6LiF

The fabrication technique was transferred to industries

ZnS/10B2O3 ceramic scintillator

Scintillator neutron detectors play a key role to utilize 1MW neutrons. R&D has been conducted since 2000.

Neutron absorption of 10B

4 times larger than 6Li

ZnS/10B2O3 ceramic scintillators and related counting method could successfully increase the performances on counting rate, detection efficiency and gamma ray discrimination etc..

Standard ZnS/6LiF scintillators have the decay characteristics of short and long term. New ZnS/10B2O3 ceramic scintillators could successfully decrease the long term decay part.

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

-0.5 0 0.5 1 1.5

Vo

ltag

e, V

Elapsed time, ms

Life time: 130ns

Filter: FV026

100 times

Peak Flux

Energy (eV) Remarkable decrease

of long term decay

2-dimensional detector

Position resolution : 1mm

Counting rate : 1Mcps

Detector area : 1m2

L2 : 40cm

New scintillator

Wavelength shifting fibers

Photon Counting

Backside read out (90°bend)

long d-spacing (-135Å)

Hydrogen and hydration of biologically important macromolecule (including organic compounds)

compact

fast / high efficiency

fast / high efficiency

high resolution

Compact, High resolution, High efficiency

Single Crystal Diffractometer for Biologically Important Materials “ iBIX “

High speed amplifier discriminator module

256ch x 256ch imaging detector with WLS readout

Specifications Geometry of detector module:160×160 mm Position resolution: 1 mm Neutron detection efficiency: 50% at 1.8Å Gamma sensitivity: 10-5 at 1.3 MeV Pulse pair resolution: 1 ms

Compact Neutron Imaging Detector with Wavelength Shifting Fibre (WLSF) Read-Out

Single Crystal Diffractometer for Biologically Important Materials“ iBIX “ at BL03@MLF

Signal processing module with FPGA

Compact, High resolution,

High efficiency

14 modules ( 2008 ) 16 modules ( 2012 )

A Large Area Scintillator Detector with WLSF Read-Out

Detector module

(1) Detector head

(2) Signal processing

& Encoder electronics

(3) DAQ elec.

A wide area scintillator detector has been developed using the iBIX detector technology.

Specifications Geometry of detector module:300×300 mm Pixel sise: 4×4 mm Neutron detection efficiency: 40% at 1.8Å Gamma sensitivity: 10-6 at 1.3 MeV Pulse pair resolution:

A Large Area Scintillator Detector Test at J-PARC/MLF

Specifications Geometry of detector module:196×1,370 mm Position resolution: 3 mm Neutron detection efficiency: > 70% at 1.8Å Gamma sensitivity: < 10-6 at 1.3 MeV Pulse pair resolution: 2.5 ms

Scintillator Based Large Area 1-Dimensional Neutron Detector

(Under Cooperation Between JAEA and CCLRC)

Engineering materials diffractometer “TAKUMI” at BL19@MLF

1.37m 200

Neutron

Large Area, High resolution, good stability

BL06 MIEZE Spectrometer (2011 - ) WLSF detector

Neutron Detectors in the MLF

2-d large area scintillator detector using WLSF

2-d compact scintillator detector using WLSF

BL03 Bio-Single Crystal Diffractometer ( 2007 – 2008, 2011 - )

1-d large area scintillator detector using fibre coding

BL18 Single Crystal Diffractometer (2010 - )

BL17 Vertical Neutron Reflectometer (2010 - ) WLSF detector (SANS option)

1-d He-3 gas tube Detector for many instruments

BL19 Residual Stress Diffractometer (2007 – 2008 )

BL04 Germanium detector

Red :He-3 PSD Yellow : Scintillator

Conclusions

Detectors play key roles at high-intensity pulsed neutron sources. The new ZnS/B2O3 ceramic scintillator with shorter afterglow has been developed. By using this, a compact scintillator detector and a large area WLSF detector have been developed and successfully constructed. More than 80% of the detectors in J-PARC/MLF use 3He detectors. Neutron Instruments at J-PARC need another 10,000 ℓ over the five years. In the 3He crisis, we have started to develop 3He alternatives using the new scintillator technology. We have started to develop a scintillator detector for safegard

applications. The detection efficiency of the trial product of the

new detector was around 73% of that of the He-3 detector (4atm).