Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tanigawa, Masafumi; Mukai, Yasunobu; Tobita, Hiroshi; Kurata, Noritaka*; Kobayashi, Nozomi*; Takase, Misao*; Makino, Risa; Ozu, Akira; Nakamura, Hironobu; Kurita, Tsutomu; et al.
56th Annual Meeting of the Institute of Nuclear Materials Management (INMM 2015), Vol.1, p.693 - 701, 2016/00
no abstracts in English
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:16.55(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.
Nakamura, Hironobu; Ozu, Akira; Kobayashi, Nozomi*; Mukai, Yasunobu; Sakasai, Kaoru; Nakamura, Tatsuya; Soyama, Kazuhiko; Kureta, Masatoshi; Kurita, Tsutomu; Seya, Michio
Proceedings of INMM 55th Annual Meeting (Internet), 9 Pages, 2014/07
To establish an alternative technique of He-3 neutron detector that is used for nuclear material accountancy and safeguards, we have started an R&D project to develop a new type of neutron detector (Pu NDA system) using ZnS/BO ceramic scintillator with support of Japanese government. The design of the alternative system (ASAS: Alternative Sample Assay System) is basically referenced from INVS (INVentory Sample assay system) which is passive neutron assay system of plutonium and has total 18 He-3 tubes (about 42% of counting efficiency), and the small amount of Pu in the MOX powder or Pu nitrate solution in a vial can be measured. In order to establish the technology and performance after the fabrication of the new detector progresses, we are planning to conduct demonstration activity in the early 2015 experimentally. The demonstration activity implements the confirmation of reproducibility about sample positioning, optimization of detector parameters, counting statistical uncertainty, stability (temperature and -ray change) check and figure of merit (FOM) using check source and actual MOX powder. In addition to that, performance comparison between current INVS and the ASAS are also conducted. In this paper, we present some analytical study results using a Monte-Carlo simulation code (MCNP), entire ASAS design and demonstration plan to prove technology and performance.
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.
Ozu, Akira; Kureta, Masatoshi; Haruyama, Mitsuo; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Soyama, Kazuhiko; Nakamura, Tatsuya; Sakasai, Kaoru; To, Kentaro; et al.
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2013/10
no abstracts in English
Kureta, Masatoshi; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Soyama, Kazuhiko; Nakamura, Tatsuya; Nakamura, Hironobu; Seya, Michio
Proceedings of INMM 54th Annual Meeting (CD-ROM), 8 Pages, 2013/07
Against the background of the serious shortage of He-3 gas, the ceramic scintillator neutron detectors have been developed for a safeguards-specific alternative to He-3 for neutron detection with support of Japan government (MEXT). In this paper, the evaluation of optical guide property on ceramic scintillator detectors and design of the demonstrator named Alternative Plutonium Canister Assay system (APCA).
Ozu, Akira; Takase, Misao*; Haruyama, Mitsuo; Kurata, Noritaka*; Kobayashi, Nozomi*; Tobita, Hiroshi; Kureta, Masatoshi; Nakamura, Tatsuya; To, Kentaro; Suzuki, Hiroyuki; et al.
no journal, ,
no abstracts in English
Ozu, Akira; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Yoshino, Seiji; Kureta, Masatoshi; Nakamura, Tatsuya; Soyama, Kazuhiko; Nakamura, Hironobu; Seya, Michio; et al.
no journal, ,
no abstracts in English
Ozu, Akira; Kureta, Masatoshi; Kobayashi, Nozomi*; Takase, Misao*; Kurata, Noritaka*; Tobita, Hiroshi; Haruyama, Mitsuo; Nakamura, Tatsuya; Suzuki, Hiroyuki; Sakasai, Kaoru; et al.
no journal, ,
no abstracts in English