Measurement of displacement cross-sections of Nb irradiated by protons with kinetic energy range between 0.4 and 3 GeV

Meigo, Shinichiro; Nakano, Keita*; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*

EPJ Web of Conferences, 284, p.05001_1 - 05001_4, 2023/05

https://doi.org/10.1051/epjconf/202328405001

In high-intensity proton accelerator facilities such as Accelerator Driven System (ADS) and the spallation neutron source, it is crucial to evaluate the damage of beam-interception materials and accelerator components, such as a magnet coil. The displacement per atom (dpa) is used as a damage index, which is derived by integrating the particle flux and the displacement cross section based on the NRT model. Although the dpa is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. To obtain the data for superconducting materials for high-intensity accelerators and magnets, the displacement cross section of Nb for proton irradiation with a kinetic energy range between 0.4 and 3 GeV was measured. For sustaining damage in the sample, the Nb sample was cooled at a cryogenic temperature (8 K), where the recombination of Frenkel pairs due to thermal motion was well suppressed with maintaining the normal conductivity to maintain Matthiessen's rule. The displacement cross section of Nb was calculated using the PHITS code, and was compared with the present experimental results. It was found that the widely utilized NRT model overestimates the cross section by a factor of 2, as suggested by the previous works. It was also found that the calculation with a recently proposed athermal recombination corrected (arc) model based on Molecular Dynamics (MD) shows good agreement with the present data.

Demonstration of a neutron resonance transmission analysis system using a laser-driven neutron source

Hironaka, Kota; Ito, Fumiaki*; Lee, J.; Koizumi, Mitsuo; Takahashi, Tone; Suzuki, Satoshi*; Yogo, Akifumi*; Arikawa, Yasunobu*; Abe, Yuki*

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

Neutron resonance transmission analysis (NRTA) is a method for non-destructive measurement of nuclear material by using a time-of-flight (TOF) technique with a pulsed neutron source. For NRTA system to carry out the short-distance TOF measurements with high resolutions, a short-pulsed neutron source is required. Laser-driven neutron sources (LDNSs) is very suitable as such a neutron source because of its short pulse width. Moreover, the compactness of the laser system is also expected due to the remarkable development of laser technology in recent years. In the present study, we have developed a technology for applying LDNS to the NRTA system and conducted the demonstration experiment using the LFEX laser at Osaka University to investigate the feasibility of the system. In this experiment, we successfully observed the neutron resonance peaks of indium and silver samples.

Research for improving the safety of accelerator facilities; Evaluation of radiation damage on metallic structural materials with high accuracy

Meigo, Shinichiro; Iwamoto, Yosuke; Matsuda, Hiroki

Isotope News, (774), p.27 - 31, 2021/04

https://www.jrias.or.jp/books/cat3/2021/774.html

no abstracts in English

Measurement of displacement cross section of structural materials utilized in the proton accelerator facilities with the kinematic energy above 400 MeV

Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*

EPJ Web of Conferences, 239, p.06006_1 - 06006_4, 2020/09

https://doi.org/10.1051/epjconf/202023906006

R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.

Measurement of displacement cross-section for structural materials in High-Power Proton Accelerator Facility

Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Iwamoto, Hiroki; Hasegawa, Shoichi; Maekawa, Fujio; Yoshida, Makoto*; Ishida, Taku*; Makimura, Shunsuke*; Nakamoto, Tatsushi*

Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.499 - 501, 2018/06

https://doi.org/10.18429/JACoW-IPAC2018-MOPML045

no abstracts in English

Operator's contribution on the improvement of RII scheme against the process operation at PCDF

Nakamura, Hironobu; Shimizu, Yasuyuki; Makino, Risa; Mukai, Yasunobu; Ishiyama, Koichi; Kurita, Tsutomu; Ikeda, Atsushi*; Yamaguchi, Katsuhiro*

Proceedings of INMM 57th Annual Meeting (Internet), 9 Pages, 2016/07

Regarding the Integrated Safeguards (IS) in Japan, the implementation of IS has been started on September 2004, and the concept has been introduced to the JNC-1 facilities since August 2008. Then, random interim inspection with short notice and reducing person-days of inspection (PDI) was introduced instead of traditional scheduled IIV in order to improve deterrence of the nuclear material diversion with timeliness goal. And it was agreed that it should be evaluated and reviewed because RII was designed when inter-campaign. In JAEA, we decided to restart PCDF campaign to reduce potential safety risks of reprocessing facilities. To adopt the RII scheme to the process operation in campaign, JAEA proposed a new scheme to JSGO and IAEA without increasing PDI and reducing detection probability. As a result of the discussion, it was agreed and successfully introduced since March 2014. The new scheme for PCDF consists of scheduled inspection (fixed-day RII), reduction of estimated material for the verification, implementation of remote monitoring with data provision, improvement of operational status check list, introduction of NRTA and MC&A data declaration with timeliness. Though the operator's workloads for information provision were increased, we could manage to balance IS requirement with implementation of our operation successfully. This contribution was helped to safeguards implementation and our operation for 2 years.

NRTA data processing system: PROMAC-J

Ikawa, Koji; Ihara, Hitoshi; Nishimura, Hideo

JAERI-M 93-182, 160 Pages, 1993/09

JAERI-M-93-182.pdf:3.31MB

no abstracts in English

A Study of statistical tests for near real time materials accountancy, 2

Ihara, Hitoshi; Yamamoto, Yoichi

Dai-13-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, p.20 - 27, 1992/06

no abstracts in English

Development of a real time simulation system to demonstrate the use of the near-real-time materials accountancy, II

Ihara, Hitoshi; Yamamoto, Yoichi; Nishimura, Hideo; Ikawa, Koji;

Dai-11-Kai Kaku Busshitsu Kanri Gakkai Nenji Taikai Rombunshu, p.23 - 30, 1990/06

no abstracts in English

A Study of statistical tests for Near-Real-Time Materials Accountancy using field test data of Tokai Reprocessing Plant

Ihara, Hitoshi; Nishimura, Hideo; Ikawa, Koji; ; ;

JAERI-M 88-059, 105 Pages, 1988/03

JAERI-M-88-059.pdf:2.9MB

no abstracts in English