Development of Scintillator Detectors at J-PARC/MLF J-PARC, JAEA Kazuhiko Soyama Basic Energy Sciences Neutron & Photon Detector Workshop August 1-3, 2012 Holiday Inn Gaithersburg, USA
Contents 1. J-PARC, High intensity pulsed neutron source 2. Scientific demands and neutron detectors 3. State of the art 4. J-PARC activity
Hadrons Science Facility Materials and Life Sciences Facility Experimental Facilities 50 GeV Synchrotron Neutrino experimental facility North to South Accelerators 3 GeV Synchrotron Linac J-PARC Facility (KEK/JAEA) JRR-3 Bird s eye photo in January of 2008
Linac(330m) 3GeV Synchrotron (350m) 50GeV Synchrotron(1600 m) Superconducting magnets for the neutrino beamline
Materials and Life Experimental Facility Mercury Target for Neutrons #1 Hall Neutron Source #2 Hall #1 Hall
Moderation of neutron Reduce neutron energy from MeV to mev Be reflector Moderator (20K Hydrogen) Coupled moderator High intensity, Low resolution proton(δt~1ms) accelerator 0.7ms moderator contains hydrogen atoms Hg target Ag-In-Cd decoupler Spallation process Decoupled moderator Medium resolution mass of hydrogen ~ mass of neutron Cd and Ag-In-Cd absorb thermal neutrons Cd poisoning plate Decoupled poisoned moderator High resolution
Pulse Peak Intensity(n/cm 2 /s/sr/ev/pulse) Time Averaged Intensity (for CM) :1/4 of ILL s Cold source Pulse Peak Intensity (for CM) :~100 of ILL s Cold source Time-integrated Thermal Neutron Flux Pulse Width in FWHM at 10meV 10 17 10 16 Decoupled Coupled Hg Target Be reflector 1MW 25Hz 100 times 0.95 10+8 n/sec/cm 2 33 msec DM 0.65 10+8 n/sec/cm 2 22 msec PM 4.6 10+8 n/sec/cm 2 92 msec CM 10 15 Poisoned (center) ILL cold (56 MW) Proton Hg target BL-23 Chopper BL-22 Imaging 10 14 10-4 10-3 10-2 10-1 10 0 10 1 Energy (ev) Flux values 10m from the moderator
Neutron Instruments at Materials and Life Science Facility SPICA (KEK) SuperHRPD (KEK) NOP (KEK) NOBORU (JAEA) ANNRI (Tokyo Tech. U., JAEA, Hokkaido U.) PLANET (U. of Tokyo, JAEA) ibix (Ibaraki Pref.) DNA (JAEA) HRC (KEK) 4SEASONS (JAEA, KEK, Tohoku U.) AMATERAS (JAEA) NOVA (NEDO, KEK) TAIKAN (JAEA) imateria (Ibaraki Pref.) SOFIA (KEK) SHARAKU(JAEA) SENJU (JAEA) TAKUMI (JAEA)
Molecular recognition and chemical reaction in the protein field 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. Principle of protein structure 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 application to drug design and so on. drug design
Detector requirement of single crystal diffractometer for biologically important materials Required detector performance Surface area : 1.1 m 2 (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
The state of the art on neutron detectors for single crystal diffractometer BNL Curved Detector ISIS 2D Fibre Coded Ordela Model2250 Area Type Resolution Efficiency Counting rate g /n ratio Reference 1500 200 mm Gas, MWPC Charge division 1.3 1.3 mm 50% (1.5A ), 90% (5A ) 10 6 / sec 記載なし http://www.inst.bnl.gov/gasdetectorlab/ neutrons/neutron_brochure.pdf 192 192 mm Sci., ZnS/LiF Fibre Coded 3 3 mm 20% (1A ) 10 5 / sec/unit <10-8 http://jra2.neutron-eu.net/files/ Nigel_Rhodes.pdf 250 250 mm Gas, MWPC Delay line 2.5 2.5mm 70% (3A ), 35% (1A ) 10 4 / sec 記載なし http://www.ordela.com/ about/index.htm area area area Evaluation Posi.Resolution g /n Posi.Resolution g /n Posi.Resolution g /n efficiency counting rate efficiency counting rate efficiency counting rate
Voltage, V The New Ceramic Scintillator developed for J-PARC - A Key Technology to High Intensity Pulsed Neutron Science F Scintillator neutron detectors play a key role to utilize 1MW neutrons. R&D has been conducted since 2000. ZnS/ 6 LiF Neutron absorption of 10 B 4 times larger than 6 Li ZnS/ 10 B 2 O 3 ceramic scintillator 100 times Peak Flux Standard ZnS/ 6 LiF scintillators have the decay characteristics of short and long term. New ZnS/ 10 B 2 O 3 ceramic scintillators could successfully decrease the long term decay part. Energy (ev) ZnS/ 10 B 2 O 3 ceramic scintillators and related counting method could successfully increase the performances on counting rate, detection efficiency and gamma ray discrimination etc.. The fabrication technique was transferred to industries Remarkable decrease of long term decay 0.01 0-0.01 Life time: 130ns -0.02-0.03-0.04-0.05 Filter: FV026-0.06-0.07-0.5 0 0.5 1 1.5 Elapsed time, ms
Single Crystal Diffractometer for Biologically Important Materials ibix Hydrogen and hydration of biologically important macromolecule (including organic compounds) long d-spacing (-135Å) 2-dimensional detector Position resolution : 1mm Counting rate : 1Mcps Detector area : 1m2 L2 : 40cm Compact, High resolution, High efficiency fast / high efficiency New scintillator Wavelength shifting fibers Backside read out (90 bend) Photon Counting high resolution compact fast / high efficiency
Compact Neutron Imaging Detector with Wavelength Shifting Fibre (WLSF) Read-Out Single Crystal Diffractometer for Biologically Important Materials ibix at BL03@MLF Compact, High resolution, High efficiency 14 modules ( 2008 ) 16 modules ( 2012 ) Specifications Geometry of detector module:160 160 mm Position resolution: 1 mm Neutron detection efficiency: 50% at 1.8A Gamma sensitivity: 10-5 at 1.3 MeV Pulse pair resolution: 1 ms Signal processing module with FPGA High speed amplifier discriminator module 256ch x 256ch imaging detector with WLS readout
A Large Area Scintillator Detector with WLSF Read-Out A wide area scintillator detector has been developed using the ibix detector technology. Detector module SENJU BL18 (2) Signal processing & Encoder electronics (1) Detector head (3) DAQ elec. Specifications Geometry of detector module:300 300 mm Pixel sise: 4 4 mm Neutron detection efficiency: 40% at 1.8A Gamma sensitivity: 10-6 at 1.3 MeV Pulse pair resolution: <5 ms
A Large Area Scintillator Detector Test at J-PARC/MLF
Scintillator Based Large Area 1-Dimensional Neutron Detector Engineering materials diffractometer TAKUMI at BL19@MLF (Under Cooperation Between JAEA and CCLRC) Large Area, High resolution, good stability 1.37m 200 Neutron Specifications Geometry of detector module:196 1,370 mm Position resolution: 3 mm Neutron detection efficiency: > 70% at 1.8A Gamma sensitivity: < 10-6 at 1.3 MeV Pulse pair resolution: 2.5 ms
Neutron Detectors 1-d He-3 gas tube Detector for many instruments in the MLF BL06 MIEZE Spectrometer (2011 - ) WLSF detector Red :He-3 PSD Yellow : Scintillator 2-d compact scintillator detector using WLSF BL17 Vertical Neutron Reflectometer (2010 - ) WLSF detector (SANS option) BL18 Single Crystal Diffractometer (2010 - ) 2-d large area scintillator detector using WLSF BL03 Bio-Single Crystal Diffractometer ( 2007 2008, 2011 - ) BL04 Germanium detector BL19 Residual Stress Diffractometer (2007 2008 ) 1-d large area scintillator detector using fibre coding
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 3 He detectors. Neutron Instruments at J-PARC need another 10,000 l over the five years. In the 3 He crisis, we have started to develop 3 He 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).