Development of thin SiC neutron detector with high radiation resistance (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*

JAEA-Review 2019-042, 43 Pages, 2020/03

JAEA-Review-2019-042.pdf:25.64MB

JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Thin SiC Neutron Detector with High Radiation Resistance". In the works for debris retrieval, it is required to install subcritical surveillance radiation monitors that can surely work for long time under extremely high gamma-ray radiation environment. However, there have been problems such as remote control of conventional radiation monitors is difficult because heavy radiation shields are needed. In the present study, we will develop a neutron detector using thin, light-weight and radiation-resistive silicon carbide (SiC) that has low sensitivity to gamma-rays as well as the data collection system in collaboration with the U.K. Using this system, the performance tests will be conducted supposing the real debris retrieval including the irradiation tests. Based on the results, we will conduct research and development aiming to make the system ready for use in real decommissioning works.

Monte Carlo radiation transport modelling of the current-biased kinetic inductance detector

Malins, A.; Machida, Masahiko; Vu, TheDang; Aizawa, Kazuya; Ishida, Takekazu*

Nuclear Instruments and Methods in Physics Research A, 953, p.163130_1 - 163130_7, 2020/02

https://doi.org/10.1016/j.nima.2019.163130

New approach to measure double-differential charged-particle emission cross sections of several materials for a fusion reactor

Kondo, Keitaro; Takagi, Satoshi*; Murata, Isao*; Miyamaru, Hiroyuki*; Takahashi, Akito*; Kubota, Naoyoshi; Ochiai, Kentaro; Nishitani, Takeo

Fusion Engineering and Design, 81(8-14), p.1527 - 1533, 2006/02

https://doi.org/10.1016/j.fusengdes.2005.08.070

In a fusion reactor development, double-differential charged-particle emission cross sections(DDXc) are necessary to estimate nuclear heating and material damages of candidate materials irradiated with neutrons. Especially in light nuclei such as Be, Li, and C, nuclear reactions are complicated and difficult to estimate energy spectra of emitted particles based only on theoretical calculations Therefore development of a new technique for precise measurements of DDXc is quite important. Recently we successfully developed a new spectrometer for measurement of DDXc using a pencil-beam DT neutron source of FNS in JAERI. In the present study we carried out measurements of DDXc of Be, C, F, and Al using the spectrometer. The present technique was valid from the result of measurement for the Al(n,x) reactions. Slight differences appeared between measured data and evaluation or previous experimental values for Be(n,x) reactions at backward scattering angle and in lower energy region.

Development of 2-d position-sensitive neutron detector with individual readout; Operation test and establishment of detection system by means of neutron beam

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% CH (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.

Development of ZnS/LiF scintillating and MSGC neutron detectors in JAERI

Nakamura, Tatsuya; Katagiri, Masaki; Yamagishi, Hideshi; Tanaka, Hiroki; Sakasai, Kaoru; Soyama, Kazuhiko

Hamon, 15(1), p.67 - 73, 2005/01

https://doi.org/10.5611/hamon.15.67

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.

Usage of a capillary plate as a pre-gas-amplification device for a neutron microstrip gas chamber

Nakamura, Tatsuya; Masaoka, Sei; Yamagishi, Hideshi; Sakasai, Kaoru; Soyama, Kazuhiko; Aizawa, Kazuya

IEEE Transactions on Nuclear Science, 51(4), p.1519 - 1523, 2004/08

https://doi.org/10.1109/TNS.2004.832701

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.

Discrimination of neutrons and ray by a neutron detector comprising a superconducting tunnel junction on a single crystal of LiBO

Nakamura, Tatsuya; Katagiri, Masaki; Soyama, Kazuhiko; Ukibe, Masahiro*; Ikeuchi, Takashi*; Okubo, Masataka*

Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.402 - 404, 2004/08

https://doi.org/10.1016/j.nima.2004.05.020

We evaluated the neutron--rays discrimination of the neutron detector comprising a superconducting tunnel junction (STJ) on the single crystal of LiBO. The neutron detector was irradiated with X-rays, -rays and neutrons, and the signal pulses were analyzed including pulse height distributions and rise times. It was found that the most of the signal pulses for the neutron-events exhibited slower rise times than those for X-rays and -rays. This indicated the capability of neutron--rays discrimination of the detector using the differences in the decay time of the signal current.

Neutron zooming detector using electronic zooming TV readout system

Soyama, Kazuhiko; Matsubayashi, Masahito; Masaoka, Sei; Nakamura, Tatsuya; Matsumura, Tatsuya*; Kinoshita, Katsuyuki*

JAERI-Research 2003-032, 22 Pages, 2004/03

JAERI-Research-2003-032.pdf:1.83MB

The neutron zooming tube has been developed using electronic zooming TV readout system for an X-ray microscope. This system consists of the photocathode, the electro-magnetic coil assembly and the CCD TV camera etc.. The photocathode consists of transmission type CsI layer in combination with neutron converters such as Gd foil. The system position sensitive resolution of 20m has been obtained using neutron converter. We have found that it is determined from the distance between the CsI layer and the neutron converter, then the limiting resolution could be improved.

Cryogenic neutron detector comprising an InSb semiconductor detector and a supercritical helium-3 gas converter

Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*

Review of Scientific Instruments, 75(2), p.340 - 344, 2004/02

https://doi.org/10.1063/1.1642747

We evaluated the neutron-detection characteristics of a proposed cryogenic neutron detector comprising an InSb semiconductor detector and a helium-3 gas converter. The neutron detector was operated at 4.2 K with helium-3 gas filling up to 1.5 atm, at which the density of the helium-3 nucleus corresponds to that at 160 atm at room temperature. The secondary particles generated by the He(n,p) T reaction were successfully detected by the InSb detector with a time response of 80 nsec at all tested gas pressures.

Development of micro-strip gas chamber with individual readout

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.