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Nakamura, Tatsuya; Tanaka, Hiroki; Yamagishi, Hideshi; Soyama, Kazuhiko; Aizawa, Kazuya; Ochi, Atsuhiko*; Tanimori, Toru*
Nuclear Instruments and Methods in Physics Research A, 573(1-2), p.187 - 190, 2007/04
Times Cited Count：9 Percentile：54.96(Instruments & Instrumentation)We have been developing a neutron imaging gas detector with a high spatial resolution and with a high temporal response for the neutron scattering instruments at the pulsed neutron source in the Japan proton accelerator research complex. The gas detector system with individual read-outs was developed to meet the requirements for the instruments for neutron reflectometry or for small angle neutron scattering. The performances of the prototype detector using a multi-wire (MW) or micro-strip (MS) detector head were evaluated using a collimated neutron beam, and we confirmed the MS detector exhibiting a spatial resolution of 1.5 mm and a pulse-pair resolution of about 100 ns with a gas pressure of 6 atm helium with a mixture of 30% CF
. The performances for the MS detector were also evaluated up to the total gas pressure of 8 atm.
LiF scintillating and MSGC neutron detectors in JAERINakamura, Tatsuya; Katagiri, Masaki; Yamagishi, Hideshi; Tanaka, Hiroki; Sakasai, Kaoru; Soyama, Kazuhiko
Hamon, 15(1), p.67 - 73, 2005/01
Development of scintillating and gaseous neutron detectors in Japan Atomic Energy Research Institute is briefly described. In this paper, the performances of the developed 2-d neutron detectors, concerning ZnS/LiF scintillating detectors with wavelength shifting fiber read-out and micro-strip gas chambers with individual read-out, are presented.
Nakamura, Tatsuya; Masaoka, Sei; Yamagishi, Hideshi; Sakasai, Kaoru; Soyama, Kazuhiko; Aizawa, Kazuya
IEEE Transactions on Nuclear Science, 51(4), p.1519 - 1523, 2004/08
Times Cited Count：2 Percentile：18.00(Engineering, Electrical & Electronic)A capillary plate (CP) comprising an assembly of fine glass tubes was applied as a pre-gas-amplification device for a microstrip gas chamber (MSGC) operating under high-gas pressure of helium-3 for use in neutron detection. The collection efficiency of the electrons between the CP and MSGC was maximally 17% using neutrons. The effective gas gain of the detector system was 
600 at a gas pressure of 3 atm with a 10% mixture of ethane with helium-3, confirming the feasibility of the CP as a pre-gas-amplification device. Moreover, we demonstrated that the coincidence measurement of the signals between the CP and the anodes of MSGC decreased the background levels of electronics noise, electronic discharges, and 
-rays, indicating that a detector system with a low background can be constructed using the CP.
Yamagishi, Hideshi; Nakamura, Tatsuya; Soyama, Kazuhiko; Masaoka, Sei; Aizawa, Kazuya
Review of Scientific Instruments, 75(7), p.2340 - 2345, 2004/07
Times Cited Count：9 Percentile：44.48(Instruments & Instrumentation)A new instrument system with the capability of secondary-particle discrimination (InSPaD) was studied for the development of two-dimensional neutron detectors (2D-ND) filled with helium-3 gas and with high spatial resolution. The InSPaD can discriminate between the tracks of a proton and a triton created in the nuclear reaction 
He(
,
)
by simply setting the level of discriminators appropriately in each signal channel, and the system exhibits a high spatial resolution, high counting rate, low background, and stability. The simulations of the 2D-ND equipped with the InSPaD revealed spatial resolutions of 0.46 mm in full width at half maximum for a 10% mixture of C
H
with helium-3 at 0.3 MPa. The results of neutron-detection experiments using a microstrip gas chamber, including the range of the secondary particles and the pulse-height distribution, agreed well with the simulated results, indicating the feasibility of the InSPaD.
Nakamura, Tatsuya; Masaoka, Sei; Yamagishi, Hideshi; Soyama, Kazuhiko; Aizawa, Kazuya
Proceedings of ICANS-XVI, Volume 1, p.441 - 446, 2003/07
Development of a Micro-Strip Gas Chamber(MSGC) in JAERI is presented. The performances we aim at are counting rate 
10
, position resolution 
1
, detection efficiency 60% at thermal neutron and good n/gamma discrimination. Our two-dimensional gas detector consists of a micro strip plate printed on a polyimide substrate and a high pressure gas chamber which has all the signal lines are directly taken out (256ch individual readout) and withstands the pressure of 10bar 
. The individual signal readout opens the way to realize high counting rate and high position resolution at the same time. We carried out range measurements of secondary particles to confirm the range measuring power of the MSGC with that read out method. The measured ranges in the gas of 3bar helium mixed with 
ethane is 3mm, 9.5mm for triton and proton, respectively. Those values are well agreed with theoretical estimation and we could show the feasibility of the precise measurement of the ranges by the MSGC.
Masaoka, Sei; Nakamura, Tatsuya; Yamagishi, Hideshi; Soyama, Kazuhiko
JAERI-Research 2003-012, 14 Pages, 2003/06
JAERI-Research-2003-012.pdf:1.58MB
A micro-strip gas chamber (MSGC) using helium-3 gas has been developing as a two-dimensional position sensitive neutron detector for neutron scattering experiments in a high-intensity proton accelerator facility. We have developed the encode board that have built-in FPGAs (Field-Programmable Gate Array). Logics of FPGAs can be freely programmed to carry out digital processing of signals from MSGC and information of the tracks of protons and tritons can be obtained by the encode board. Therefore, the position of neutron capture (more properly the centra of the track) can be calculated by a series of data handling system. As the result of the simulation of a neutron detection experiment, it has proved that the position resolution of less than 1.6 mm can be obtained by using this data handling system.
Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro; Soyama, Kazuhiko; Yamagishi, Hideshi*; Katagiri, Masaki*
no journal, ,
We have developed scintillator detectors and gas-based detectors for beam lines of Materials and Life Science Facility (MLF) at J-PARC. As for scintillator detectors, developed are one-dimensional fiber-coded type detectors at BL19 and two-dimensional detectors using wavelength shifting fibers (WLSF) at BL03 and BL18. As for gas-based detectors, a multi-wire proportional counter (MWPC) with the readout system have been developed and installed at polarized neutron reflectometer (BL17). In this report, detailed characteristics with some experimental results of these detectors will be presented.
