Application of deep metric learning model to microscope image analysis for the determination of UOC samples in nuclear forensics analysis

Kimura, Yoshiki; Matsumoto, Tetsuya*; Yamaguchi, Tomoki

Journal of Radioanalytical and Nuclear Chemistry, 333(7), p.3541 - 3551, 2024/07

https://doi.org/10.1007/s10967-023-09300-w

Radioisotope identification algorithm using deep artificial neural network for supporting nuclear detection and first response on nuclear security incidents

Kimura, Yoshiki; Tsuchiya, Kenichi*

Radioisotopes, 72(2), p.121 - 139, 2023/07

https://doi.org/10.3769/radioisotopes.72.121

Rapid and precise radioisotope identification in the scene of nuclear detection and nuclear security incidents is one of the challenging issues for the prompt response on the detection alarm or the incidents. A radioisotope identification algorithm using a deep artificial neural network model applicable to handheld gamma-ray detectors has been proposed in the present paper. The proposed algorithm automatically identifies gamma-emitting radioisotopes based on the count contribution ratio (CCR) from each of them estimated by the deep artificial neural network model trained by simulated gamma-ray spectra. The automated radioisotope identification algorithm can support first responders of nuclear detection and nuclear security incidents without sufficient experience and knowledge in radiation measurement. The authors tested the performance of the proposed algorithm using two different types of deep artificial neural network models in application to handheld detectors having high or low energy resolution. The proposed algorithm showed high performance in identifying artificial radioisotopes for actually measured gamma-ray spectra. It was also confirmed that the algorithm is applicable to identifying U and automated uranium categorization by analyzing estimated CCRs by the deep artificial neural network models. The authors also com-pared the performance of the proposed algorithm with a conventional radioisotope identification method and discussed promising ways to improve the performance of the algorithm using the deep artificial neural network.

Monitoring technique for detection of nuclear and radioactive materials on major public events

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

Prospective features for integration of nuclear forensics capability in national framework

Tamai, Hiroshi; Okubo, Ayako; Kimura, Yoshiki; Shinohara, Nobuo; Tazaki, Makiko; Shimizu, Ryo; Suda, Kazunori; Tomikawa, Hirofumi

Proceedings of INMM 58th Annual Meeting (Internet), 6 Pages, 2017/07

Nuclear forensics is a technical measure to analyse and collate samples of illegally used nuclear materials, etc., to clarify their origins, routes, etc. and contribute to criminal identifications. Close collaboration with police and judicial organizations is essential. The national response framework is being built up with international cooperation. Discussions on promoting technical capability and regional cooperation are presented.

Current status and achievements on nuclear forensics technology developments for nuclear security

Kimura, Yoshiki; Shinohara, Nobuo; Okubo, Ayako

Nihon Genshiryoku Gakkai-Shi ATOMO, 57(12), p.782 - 786, 2015/12

no abstracts in English

Report on research and development of nuclear forensics technologies

Okubo, Ayako; Kimura, Yoshiki; Shinohara, Nobuo; Toda, Nobufumi; Funatake, Yoshio; Watahiki, Masaru; Sakurai, Satoshi; Kuno, Yusuke

JAEA-Technology 2015-001, 185 Pages, 2015/03

JAEA-Technology-2015-001.pdf:56.65MB

Nuclear forensics is the analysis of intercepted illicit nuclear or radioactive material and any associated material to provide evidence for nuclear attribution by determining origin, history, transit routes and purpose involving such material. Nuclear forensics activity includes sampling of the illicit material, analysis of the samples and evaluation of the attribution by comparing the analyzed data with database or numerical simulation. Because the nuclear forensics technologies specify the origin of the nuclear materials used illegal dealings or nuclear terrorism, it becomes possible to identify and indict offenders, hence to enhance deterrent effect against such terrorism. Worldwide network on nuclear forensics can contribute to strengthen global nuclear security regime. In this paper, the results of research and development of fundamental nuclear forensics technologies performed in Japan Atomic Energy Agency during the fiscal term of 2011-2013 were reported.

Lessons learned from the international tabletop exercise of national nuclear forensics library at JAEA

Kimura, Yoshiki; Shinohara, Nobuo; Funatake, Yoshio

Journal of Nuclear Materials Management, 42(4), p.40 - 45, 2014/00

http://www.jnmm-digital.com/jnmm/summer_2014?pg=42#pg42

Japan Atomic Energy Agency (JAEA) has initiated an R&D project on nuclear forensics technology from 2011. This project includes development of prototype national nuclear forensics library (NNFL), and the JAEA attended to the first international table top exercise of NNFL "Galaxy Serpent" held by ITWG as a part of our NNFL development project. In this paper, outline and experiences of the JAEA investigation in the table top exercise are described and the lessons learned from the experiences were discussed. Brief current status of the NNFL development project at JAEA was also introduced in the present paper. The lessons from the experiences in the exercise will be effectively applied to the development of NNFL at JAEA.

R&D status and future plan of nuclear forensics for analytical technology and national library at JAEA

Kimura, Yoshiki; Shinohara, Nobuo; Sato, Kaneaki; Toda, Nobufumi; Shinoda, Yoshiharu; Watahiki, Masaru; Kuno, Yusuke

Proceedings of INMM 54th Annual Meeting (CD-ROM), 7 Pages, 2013/07

Japan Atomic Energy Agency (JAEA) that possesses sufficient analytical capabilities to fulfil the mission of nuclear forensics technology development has started R&D project from JFY 2011. The R&D of the nuclear forensics technology at JAEA covers the development of analytical technology such as isotope and impurity measurements, morphology analysis, age determination technique, and proto-type of national nuclear forensics library. Each topic of the R&D has been promoted under the international cooperation with US-DOE. This paper will present the present status and brief results of the R&D project on nuclear forensics analytical technology and nuclear forensics library at JAEA. Some future plan of the R&D such as attribute identification of Japanese nuclear materials, data populating plan for existing nuclear materials data in JAEA fuel cycle facilities will be also introduced in the presentation.

The Impact of advanced technologies on the efficiencies of safeguards and facility operations

Hoffheins, B.; Miyaji, Noriko; Asano, Takashi; Nagatani, Taketeru; Ishiyama, Koichi; Kimura, Takashi; Kodani, Yoshiki

Proceedings of INMM 52nd Annual Meeting (CD-ROM), 10 Pages, 2011/07

Following Japan's conclusion of the Additional Protocol and the IAEA's broader conclusion regarding the peaceful nature of Japan's nuclear activities, the Japan government and facility operators have worked with the IAEA to apply integrated safeguards to increase inspection efficiency and to ensure verification correctness and completeness. These safeguards approaches rely heavily on the implementation of advanced technologies such as unattended surveillance and non-destructive assay measurement, automated nuclear material accounting, solution monitoring and remote monitoring. These technologies have enabled random interim inspections; they have also reduced the level of effort required for nuclear material accounting and inspection activities. A more comprehensive understanding of the impact of advanced technologies on operation and inspection processes would be useful for developing methodologies to support better system design and evaluation of existing systems.

Development of a high-contrast, high beam-quality, high-intensity laser

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki*; Shimomura, Takuya; Sasao, Hajime*; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Kondo, Shuji; Kanazawa, Shuhei; et al.

Reza Kenkyu, 38(9), p.669 - 675, 2010/09

https://ci.nii.ac.jp/naid/10026690779

This paper reviews the temporal contrast and spatial beam quality improvement techniques in a high intensity Ti:sapphire laser system that is based on chirped-pulse amplification (CPA). We describe a low gain optical parametric chirped-pulse amplification (OPCPA) preamplifier that uses high energy, clean pulse seeding and is shown to significantly improve the contrast to better than 10-10 relative to the peak of the main femtosecond pulse. We also report the use of a diffractive optical element for beam homogenization of a 100 J level Nd:glass green pump laser, achieving a flat-topped spatial profile with a filling factor near 80 %.