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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：56.38(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.
Tanaka, Hiroki; Yamagishi, Hideshi; Nakamura, Tatsuya; Soyama, Kazuhiko; Aizawa, Kazuya
JAERI-Research 2005-010, 16 Pages, 2005/04
JAERI-Research-2005-010.pdf:3.39MB
We have been developing the 2-d position-sensitive neutron detector with individual readout as next-generation-type detector system for neutron scattering experiments using intense pulsed neutron source. The detection system is designed to fulfill the specifications required for each neutron spectrometer, such as a count rate, efficiency, neutron/
-ray ratio, a spatial resolution and a size, by using suitable detector heads. The fundamental and imaging performances of the developed system assembled with a Multi-wire proportional counter head were evaluated using a collimated neutron beam. The system worked stably for long hours at the gas pressure of 5 atm with a mixture of 30% C
H
(0.26 atm 
He)at gas gain of 450. The spatial resolutions were 1.4, 1.6 mm (FWHM) for a cathode- and a back strip- direction, respectively, considering a beam size. It was also confirmed that the spatial uniformity of the detection efficiency over the whole sensitive detection area was rather good, 
8 % deviation from the average with the optimum discrimination level.
He for neutron detectionNakamura, Tatsuya; Masaoka, Sei; Yamagishi, Hideshi; Tanaka, Hiroki; Soyama, Kazuhiko; Aizawa, Kazuya
Nuclear Instruments and Methods in Physics Research A, 539(1-2), p.363 - 371, 2005/02
Times Cited Count：0 Percentile：0.01(Instruments & Instrumentation)We evaluated the neutron-detection performance of a capillary plate under high-pressure helium-3 in terms of the gas gain and the distribution of pulse heights, with the aim of using the device as a neutron detector and a gas preamplification device. The capillary plate exhibited a gas gain of more than 1000 up to a gas pressure of 6 atm with a 5% mixture of ethane, confirming an adequate gas gain as a neutron detector. It was also found that the rise times of the signal pulses were correlated with the range and the emission angle of the secondary particles, protons and tritons, thereby providing useful information for developing a system with position-sensitive readouts with a high spatial resolution and a low background.
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：18.41(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.
Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.399 - 401, 2004/08
Times Cited Count：1 Percentile：10.3(Instruments & Instrumentation)We evaluated the neutron-detection characteristics of a cryogenic neutron detector operating at 1.6 K, which comprises a liquid helium-3 as a neutron converter and an InSb semiconductor detector. The InSb semiconductor detector detected the protons created in the nuclear reaction 
in the liquid helium-3, where the density of that is ~600 times larger than that of the gaseous helium-3 at room temperature.
Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*
Nuclear Instruments and Methods in Physics Research A, 520(1-3), p.76 - 79, 2004/03
Times Cited Count：8 Percentile：48.81(Instruments & Instrumentation)The neutron-detection characteristics of a cryogenic neutron detector comprising an InSb semiconductor detector and a helium-3 gas converter were evaluated at a gas pressure of up to 12.5atm at 4.2K. The detector successfully detected stable neutrons under these conditions, where the density of the helium-3 gas is a few-hundred times higher than that at room temperature. It was found that the neutron detection efficiency was correlated with the gas pressure - even in a backward-detection configuration - in low-temperature, high-pressure helium-3.
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.
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Journal of Nuclear Science and Technology, 8(4), p.192 - 220, 1971/04
no abstracts in English
