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Kozawa, Takayuki; Suganuma, Takuro; Homma, Fumitaka; Higashimura, Keisuke*; Ukai, Takayuki*; Saito, Kenji
JAEA-Technology 2023-007, 24 Pages, 2023/06
JAEA-Technology-2023-007.pdf:2.24MB
To improve the reliability of the HTTR wide range monitor in a high-temperature environment, structural changes of the wide range monitor were investigated. It was clear that the structure for directly joins of the MI cable core wire and metal tube instead of the joins with lead wire is the most reliable method with shortest way. From a result of the thermal cycle tests and high temperature endurance tests for a mock-up connecting this connection parts, it was clear that the soundness of the connection part was maintained under the usage conditions of the HTTR.
Nakamura, Tatsuya; To, Kentaro; Koizumi, Tomokatsu; Kiyanagi, Ryoji; Ohara, Takashi; Ebine, Masumi; Sakasai, Kaoru
Proceedings of 2022 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference (2022 IEEE NSS MIC RTSD) (Internet), 2 Pages, 2022/11
A new thin position-sensitive scintillation neutron detectors have been developed to replace present scintillation detectors in SENJU diffractometer at J-PARC MLF. The SENJU diffractometer originally composed of 37 position-sensitive detectors, where each detector has neutron sensitive area of 256 
256 mm with a pixel size of 4 4 mm. To renew some original detectors the new detectors have been developed based on ZnS scintillator and wavelength-shifting fibers technology. The developed replacement detectors were designed with a thin thickness of 12 cm, which is 40% of the original detector. The new detectors have also improved detector performances to the original ones in terms of detection efficiency (
60% for 2-A neutrons) and count uniformity (5-8%). The produced six detector modules have been implemented to the beamline after checking their detector performances in the lab.
Shibata, Hiroshi; Takeuchi, Tomoaki; Seki, Misaki; Shibata, Akira; Nakamura, Jinichi; Ide, Hiroshi
JAEA-Data/Code 2021-018, 42 Pages, 2022/03
JAEA-Data-Code-2021-018.pdf:2.78MB
JAEA-Data-Code-2021-018-appendix(CD-ROM).zip:0.15MB
Japan Materials Testing Reactor (JMTR) in Oarai Research and Development Institute of the Japan Atomic Energy Agency has been developing various reactor materials, irradiation techniques and instruments for more than 30 years. Among them, the development of self-powered neutron detectors (SPNDs) and gamma detectors (SPGDs) has been carried out, and several research results have been reported. However, most of the results are based on the design study of the detector development and the results of in-core irradiation tests and gamma irradiation tests using Cobalt-60. In this report, a numerical code is developed based on the paper "Neutron and Gamma-Ray Effects on Self-Powered In-Core Radiation Detectors" written by H.D. Warren and N.H. Shah in 1974, in order to theoretically evaluate the self-powered radiation detectors.
Mochimaru, Takanori*; Koizumi, Mitsuo; Takahashi, Tone; Hironaka, Kota; Kimura, Yoshiki; Sato, Yuki; Terasaka, Yuta; Yamanishi, Hirokuni*; Wakabayashi, Genichiro*
Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11
no abstracts in English
Nakamura, Tatsuya; To, Kentaro; Koizumi, Tomokatsu; Kiyanagi, Ryoji; Ohara, Takashi; Ebine, Masumi; Sakasai, Kaoru
Proceedings of 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2020), Vol.1, p.483 - 484, 2021/09
Two-dimensional neutron detectors were developed for the extension of SENJU time-of-flight Laue single crystal neutron diffractometer in J-PARC MLF. The detectors are to be installed at the additional detector bank for the SENJU instrument. The detector module is made based on ZnS scintillator and wavelength-shifting fiber technology, where each detector module maintains a neutron-sensitive area of 256256 mm with a pixel size of 44 mm. To meet the tight space limitation in the instrument, the detector was designed as compact as possible. The detector has a depth of 170 mm, which is about 40% smaller than that of the original SENJU detector. All four produced detectors exhibited similar detector performances: detection efficiency 50-60% for 2-
neutron, 
Co gamma-ray sensitivity 110
, count uniformity 3-6%.
Nakamura, Tatsuya; Kawasaki, Takuro; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru
Proceedings of 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2018) (Internet), 3 Pages, 2019/10
A two-dimensional scintillation neutron detector with a submillimeter spatial resolution was developed for pulsed neutron diffraction imaging at the J-PARC MLF. The detector comprised the thin, single ZnS/
LiF scintillator screen coupled with the crossed wavelength-shifting fiber array for light collection. For a high spatial resolution, the wavelength shifting fibers with diameter of 0.1 mm were used them for assembling the detector. The prototype detector that has a neutron-sensitive area of 24 24 mm
exhibited a spatial resolution of 0.20
0.06 mm and 0.160.06 mm for x and y directions, respectively. The detector had a detection efficiency of 7
for thermal neutrons with a Co 
-ray sensitivity in the order of 10
. In this paper detailed detector design is presented together with experimental results using the pulsed neutron beam.
Nakamura, Tatsuya; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru
Proceedings of 2016 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2016), Vol.2, p.1506 - 1508, 2018/01
Position-dependent neutron sensitivity within an element of the scintillator / wavelength-shifting fiber coil (SFC) was evaluated by using a collimated pulsed neutron beam at the J-PARC/MLF. The collimated beam that has a size of 1 1 mm was scanned over the SFC element. The neutron counts were recorded and plotted in each incident position. The scanning results showed less neutron sensitivity at the juncture of the rolled scintillator, suggesting less light collection efficiency or a lack of scintillator materials due to imperfect manufacturing process.
He-alternative HLNC-type counter; High Level Neutron counter-Boron (HLNB)Henzlova, D.*; Menlove, H. O.*; Tanigawa, Masafumi; Mukai, Yasunobu; Nakamura, Hironobu
EUR-28795-EN (Internet), p.313 - 323, 2017/00
Facing the depletion of He gas supply and the continuing uncertainty of options for future resupply, Los Alamos National Laboratory (LANL) designed and built a He free full scale thermal neutron coincidence counter based on boron-lined parallel-plate proportional technology. The counter was designed as a direct alternative to High Level Neutron Coincidence counter (HLNC-II). This paper provides a summary of performance evaluation of HLNB under realistic field conditions at Plutonium Conversion Development Facility (PCDF) of Japan Atomic Energy Agency (JAEA). The field test included a range of small to large mass MOX materials that represent realistic process samples and provided key insight on and validation of the feasibility of HLNB as a safeguards instrument in realistic facility environment. In particular, the results of verification measurements demonstrate that HLNB is capable to satisfy ITV expected for HLNC-II-type counter of 2.1% in 300s measurement time.
He NDA detector systemKoizumi, Mitsuo; Sakasai, Kaoru; Kureta, Masatoshi; Nakamura, Hironobu
Nihon Genshiryoku Gakkai-Shi ATOMO
, 58(11), p.642 - 646, 2016/11
no abstracts in English
He Alternative Neutron Detectors (ASAS), 1; Design and fabrication of ASAS detectorOzu, Akira; Tobita, Hiroshi; Kureta, Masatoshi; Tanigawa, Masafumi; Mukai, Yasunobu; Nakamichi, Hideo; Nakamura, Hironobu; Kurita, Tsutomu; Seya, Michio
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-36-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/12
Against the background of the serious shortage of He gas, the Japan Atomic Energy Agency (JAEA) has newly developed an alternative ZnS ceramic scintillation neutron detector for the safeguards, with the support of the government (MEXT). A demonstrator of plutonium inventory sample assay system (ASAS) has been also developed as an alternative HLNCC (High Level Neutron Coincidence Counter). The results from numerical simulations using Monte-Carlo code MCNPX showed that the fundamental performances of ASAS equipped with the 24 alternative neutron detectors, such as neutron detection efficiency and die-away time, equal to or higher than those of conventional HLNCC could be obtained. Here we present the inner mechanical structure of ASAS, together with the results of the simulating design.
Ozu, Akira; Takase, Misao*; Haruyama, Mitsuo; Kurata, Noritaka*; Kobayashi, Nozomi*; Kureta, Masatoshi; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Suzuki, Hiroyuki; et al.
Nuclear Instruments and Methods in Physics Research A, 798, p.62 - 69, 2015/10
Times Cited Count：2 Percentile：17.57(Instruments & Instrumentation)The light transport properties of scintillator light inside alternative He-3 neutron detector modules using scintillator sheets have been investigated by a ray-tracing simulation code. The detector module consists of a light-reflecting tube, a thin rectangular ceramic scintillator sheet laminated on a glass plate, and two photo-multiplier tubes (PMTs) mounted at both ends of the detector tube. The light induced on the surface of the scintillator sheet via nuclear interaction between the scintillator and neutrons are detected by the two PMTs. The light output of various detector modules in which the scintillator sheets are installed with several different arrangements were examined and evaluated in comparison with experimental results. The results derived from the simulation reveal that the light transport property is strongly dependent on the arrangement of the scintillator sheet inside the tube and the shape of the tube.
Seya, Michio; Naoi, Yosuke; Kobayashi, Naoki; Nakamura, Takahisa; Hajima, Ryoichi; Soyama, Kazuhiko; Kureta, Masatoshi; Nakamura, Hironobu; Harada, Hideo
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/01
The Integrated Support Center for Nuclear Non-proliferation and Nuclear Security (ISCN) of Japan Atomic Energy Agency (JAEA) has been conducting (based on collaborations with JAEA other centers) the following basic technology development programs of advanced non-destructive detection/measurement of nuclear material for nuclear security and nuclear non-proliferation. (1) The demonstration test of the Pu-NDA system for spent fuel assembly using PNAR and SINRD (JAEA/USDOE(LANL) collaboration, completed in JFY2013), (2) Basic development of NDA technologies using laser Compton scattered -rays (Demonstration of an intense mono-energetic -ray source), (3) Development of alternative to He-3 neutron detection technology, (4) Development of neutron resonance densitometry (JAEA/JRC collaboration)This paper introduces above programs.
Takeuchi, Tomoaki; Otsuka, Noriaki; Shibata, Hiroshi; Nagata, Hiroshi; Endo, Yasuichi; Matsui, Yoshinori; Tsuchiya, Kunihiko
KAERI/GP-418/2015, p.110 - 112, 2015/00
irradiation experiments with a Co source were carried out for developing Self-Powered Gamma Detectors (SPGDs) with lead (Pb) emitter and Self-Powered Neutron Detectors (SPNDs) with Pt-40%Rh emitter prior to in-core irradiation experiments. The results showed the output currents of the SPGDs were proportional to the dose rate in the range from about 200-6000 Gy/h with about 10% accuracy. In the case of SPNDs, the output currents flowed in inverse direction and were an order of magnitude lower compared with that of the SPGDs. These different behaviors of the output currents are considered to be caused by the difference in the emitter sizes and the current component originated at the MI cables.
Ozu, Akira; Takase, Misao*; Kurata, Noritaka*; Kobayashi, Nozomi*; Tobita, Hiroshi; Haruyama, Mitsuo; Kureta, Masatoshi; Nakamura, Tatsuya; Suzuki, Hiroyuki; To, Kentaro; et al.
Proceedings of 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference; 21st International Symposium on Room-Temperature Semiconductor X-ray and -ray detectors (NSS/MIC 2014), 5 Pages, 2014/00
In Japan Atomic Energy Agency, the helium-3 alternative neutron detector using ceramic scintillators for nuclear safeguards is under development with the support of the government. The alternative detector module consists of four components: an aluminum regular square tube, a light reflecting foil put on the inner surface of the square tube, a rectangular scintillator sheet sintered on a glass plate, and two PMTs provided at both ends of the tube. The scintillator sheet is fit on the diagonal inside the square tube. The light transport property of scintillator lights inside the tube influences on the fundamental performance of the alternative detector. Therefore, the properties of the lights emitted on the surface of the scintillator sheet and scintillation lights passing through the glass plate to the PMTs in several arrangements of the scintillator in the tubes were investigated with a ray-tracing simulation. The results are described in comparison with the experimental results.
LiF scintillator and wavelength shifting fibers with high spatial resolution and with low gamma-ray sensitivityNakamura, Tatsuya; To, Kentaro; Kawasaki, Takuro; Honda, Katsunori; Birumachi, Atsushi; Ebine, Masumi; Sakasai, Kaoru; Soyama, Kazuhiko; Katagiri, Masaki*
Proceedings of 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference; 21st International Symposium on Room-Temperature Semiconductor X-ray and -ray detectors (NSS/MIC 2014), p.1751 - 1753, 2014/00
The ZnS scintillator-based two-dimensional detector was developed for a time-of-flight neutron imaging with a high spatial resolution and a low -ray sensitivity. The detector is comprised of a thin ZnS scintillator with crossed wavelength-shifting-fibers (WLS fibers) arrays equipped with the fiber optic taper (FOT). The developed detector based on a neutron counting method has a high spatial resolution of less than 100 um (in FWHM) with a moderate count rate capability of several tens of thousands of cps. Of particular interest is its low -ray sensitivity of 10
. Imaging capabilities of the detector are demonstrated by using a high-intensity pulsed neutron beam at the Materials and Life Science Experimental Facility in the Japan Proton Accelerator Complex (J-PARC/MLF).
superconductorMachida, Masahiko; Koyama, Tomio*; Kato, Masaru*; Ishida, Takekazu*
Nuclear Instruments and Methods in Physics Research A, 559(2), p.594 - 596, 2006/04
Times Cited Count：11 Percentile：60.27(Instruments & Instrumentation)no abstracts in English
Endo, Akira; Kim, E.; Yamaguchi, Yasuhiro
JAERI-Data/Code 2001-027, 62 Pages, 2001/10
JAERI-Data-Code-2001-027.pdf:2.05MB
SCINFUL has been used to calculate response functions of organic scintillators for high-energy neutron spectroscopy. However, the applicability of SCINFUL is limited to the calculations for cylindrical NE213 and NE110 scintillators. In the present study, SCINFUL-CG was developed by introducing a geometry specifying function and high-energy neutron cross-section data into SCINFUL. The geometry package MARS-CG, the extended version of the CG (Combinatorial Geometry), was programmed into SCINFUL-CG to express various geometries of detectors. Neutron spectra in the regions specified by the CG can be evaluated by the track length estimator. The cross section data of silicon, oxygen and aluminum for neutron transport calculation were incorporated up to 100MeV using the data of LA150. Validity of SCINFUL-CG was examined by comparing calculated results with those by SCINFUL and MCNP and experimental data. SCINFUL-CG can be used for the designs of high-energy neutron spectrometers and neutron monitors using the organic scintillators. The present report is a user's manual of SCINFUL-CG.
Yamagishi, Hideshi; Soyama, Kazuhiko; Kakuta, Tsunemi; Ochiai, Masaaki; Iwamura, Takamichi; Saishu, Sadanori*; Urakami, Masao*; Masuda, Naohiro*; Yamauchi, Yuki*; Otani, Junichi*; et al.
JAERI-Tech 2001-053, 19 Pages, 2001/08
JAERI-Tech-2001-053.pdf:2.48MB
no abstracts in English
Yamagishi, Hideshi; Soyama, Kazuhiko; Kaneko, Junichi; Ikeda, Yujiro
JAERI-Tech 2000-085, 21 Pages, 2001/02
JAERI-Tech-2000-085.pdf:1.73MB
no abstracts in English
Yamagishi, Hideshi; Kaneko, Junichi
JAERI-Tech 2000-079, 9 Pages, 2001/01
JAERI-Tech-2000-079.pdf:0.75MB
no abstracts in English
