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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
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Contents
1. J-PARC, High intensity pulsed neutron source
2. Scientific demands and neutron detectors
3. State of the art
4. J-PARC activity
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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
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Superconducting magnets for the neutrino beamline
50GeV Synchrotron(1600 m)
3GeV Synchrotron (350m) Linac(330m)
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#1 Hall
#1 Hall
Materials and Life Experimental Facility
Mercury Target for Neutrons
Neutron Source
#2 Hall
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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
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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
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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)
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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
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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
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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
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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
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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 “
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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 )
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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:
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A Large Area Scintillator Detector Test at J-PARC/MLF
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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
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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
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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).