Local structural changes in V-Ti-Cr alloy hydrides with hydrogen absorption/desorption cycling

Ikeda, Kazutaka*; Sashida, Sho*; Otomo, Toshiya*; Oshita, Hidetoshi*; Honda, Takashi*; Hawai, Takafumi*; Saito, Hiraku*; Ito, Shinichi*; Yokoo, Tetsuya*; Sakaki, Koji*; et al.

International Journal of Hydrogen Energy, 51(Part A), p.79 - 87, 2024/01

https://doi.org/10.1016/j.ijhydene.2023.10.318

Decommissioning state of Plutonium Fuel Fabrication Facility; Dismantling the glove box W-9 and equipment interior, and a part of tunnel F1

Nagai, Yuya; Shuji, Yoshiyuki; Kawasaki, Takeshi; Aita, Takahiro; Kimura, Yasuhisa; Nemoto, Yasunori*; Onuma, Takeshi*; Tomiyama, Noboru*; Hirano, Koji*; Usui, Yasuhiro*; et al.

JAEA-Technology 2022-039, 117 Pages, 2023/06

JAEA-Technology-2022-039.pdf:11.96MB

Japan Atomic Energy Agency (JAEA) manages wide range of nuclear facilities. Many of these facilities are required to be performed adjustment with the aging and complement with the new regulatory standards and the earthquake resistant, since the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station accident. It is therefore desirable to promote decommissioning of facilities that have reached the end of their productive life in order to reduce risk and maintenance costs. However, the progress of facility decommissioning require large amount of money and radioactive waste storage space. In order to address these issues, JAEA has formulated a "The Medium/Long-Term Management Plan of JAEA Facilities" with three pillars: (1) consolidation and prioritization of facilities, (2) assurance of facility safety, and (3) back-end countermeasures. In this plan, Plutonium Fuel Fabrication Facility has been selected as primary decommissioned facility, and dismantling of equipment in the facilities have been underway. In this report, size reduction activities of the glove box W-9 and a part of tunnel F-1, which was connected to W-9, are presented, and the obtained findings are highlighted. The glovebox W-9 had oxidation & reduction furnace, and pellet crushing machine as equipment interior. The duration of activity took six years from February 2014 to February 2020, including suspended period of 4 years due to the enhanced authorization approval process

Study of the and shell gap for Ti and V by the first high-precision multireflection time-of-flight mass measurements at BigRIPS-SLOWRI

Iimura, Shun*; Rosenbusch, M.*; Takamine, Aiko*; Tsunoda, Yusuke*; Wada, Michiharu*; Chen, S.*; Hou, D. S.*; Xian, W.*; Ishiyama, Hironobu*; Yan, S.*; et al.

Physical Review Letters, 130(1), p.012501_1 - 012501_6, 2023/01

https://doi.org/10.1103/PhysRevLett.130.012501

Two-step Mott transition in Ni(S,Se); SR studies and charge-spin percolation model

Sheng, Q.*; Kaneko, Tatsuya*; Yamakawa, Kohtaro*; Guguchia, Z.*; Gong, Z.*; Zhao, G.*; Dai, G.*; Jin, C.*; Guo, S.*; Fu, L.*; et al.

Physical Review Research (Internet), 4(3), p.033172_1 - 033172_14, 2022/09

https://doi.org/10.1103/PhysRevResearch.4.033172

Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

Damped Dirac magnon in the metallic kagome antiferromagnet FeSn

Do, S.-H.*; Kaneko, Koji; Kajimoto, Ryoichi; Kamazawa, Kazuya*; Stone, M. B.*; Lin, J. Y. Y.*; Ito, Shinichi*; Masuda, Takatsugu*; Samolyuk, G. D.*; Dagotto, E.*; et al.

Physical Review B, 105(18), p.L180403_1 - L180403_6, 2022/05

https://doi.org/10.1103/PhysRevB.105.L180403

Characterizing energetic dependence of low-energy neutron-induced SEU and MCU and its influence on estimation of terrestrial SER in 65-nm Bulk SRAM

Liao, W.*; Ito, Kojiro*; Abe, Shinichiro; Mitsuyama, Yukio*; Hashimoto, Masanori*

IEEE Transactions on Nuclear Science, 68(6), p.1228 - 1234, 2021/06

https://doi.org/10.1109/TNS.2021.3077266

Secondary cosmic-ray neutron-induced single event upset (SEU) is a cause of soft errors on micro electronic devices. Multiple cell upsets (MCUs) are particularly serious problems since it is difficult to recover MCUs. In this study, we have performed irradiation tests of neutrons on 65-nm bulk SRAM at the national metrology institute of Japan (NMIJ) in Advanced Industrial Science and Technology (AIST) and measured SEU cross sections and MCU cross sections to investigate the effect on neutrons with the energies below 10 MeV on soft errors. It was found that SEU cross sections change drastically around 6 MeV. The proportion of MCU to total events does not change very much over the wide range of neutron energy. We also analyzed the total soft error rate (SER) of SEU and MCU by folding the neutron energy-dependent cross section and the flux spectra of the terrestrial neutron at New York and Tokyo. The calculated result indicates that the SER originating from the low-energy neutrons below 10 MeV is mostly negligible in the terrestrial environment.

Unveiling spin-dependent unoccupied electronic states of CoMnGe (Ga) film via Ge (Ga) absorption spectroscopy

Yoshikawa, Tomoki*; Antonov, V. N.*; Kono, Takashi*; Kakoki, Masaaki*; Sumida, Kazuki; Miyamoto, Koji*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; Sakuraba, Yuya*; et al.

Physical Review B, 102(6), p.064428_1 - 064428_7, 2020/08

https://doi.org/10.1103/PhysRevB.102.064428

Measurement of single-event upsets in 65-nm SRAMs under irradiation of spallation neutrons at J-PARC MLF

Kuroda, Junya*; Manabe, Seiya*; Watanabe, Yukinobu*; Ito, Kojiro*; Liao, W.*; Hashimoto, Masanori*; Abe, Shinichiro; Harada, Masahide; Oikawa, Kenichi; Miyake, Yasuhiro*

IEEE Transactions on Nuclear Science, 67(7), p.1599 - 1605, 2020/07

https://doi.org/10.1109/TNS.2020.2978257

Soft errors induced by terrestrial radiation in semiconductor devices have been of concern from the viewpoint of their reliability. Generally, to evaluate the soft error rates (SERs), neutron irradiation tests are performed at neutron facility. We have performed SER measurement for the 65-nm bulk SRAM and the FDSOI SRAM at RCNP in Osaka University and CYRIC in Tohoku University. In this study, we performed SER measurement for the same devices at BL10 in J-PARC MLF. The increasing rate of SER by reducing the supply voltage at J-PARC BL10 is larger than those obtained at RCNP and CYRIC. From PHITS simulation, the cause of this difference can be explained by the influence of the protons generated by neutron elastic scattering with hydrogen atoms in the package resin.

Controlled growth of boron-doped epitaxial graphene by thermal decomposition of a BC thin film

Norimatsu, Wataru*; Matsuda, Keita*; Terasawa, Tomoo; Takata, Nao*; Masumori, Atsushi*; Ito, Keita*; Oda, Koji*; Ito, Takahiro*; Endo, Akira*; Funahashi, Ryoji*; et al.

Nanotechnology, 31(14), p.145711_1 - 145711_7, 2020/04

https://doi.org/10.1088/1361-6528/ab62cf

We show that boron-doped epitaxial graphene can be successfully grown by thermal decomposition of a boron carbide thin film, which can also be epitaxially grown on a silicon carbide substrate. The interfaces of BC on SiC and graphene on BC had a fixed orientation relation, having a local stable structure with no dangling bonds. The first carbon layer on BC acts as a buffer layer, and the overlaying carbon layers are graphene. Graphene on BC was highly boron doped, and the hole concentration could be controlled over a wide range of 210 to 210 cm. Highly boron-doped graphene exhibited a spin-glass behavior, which suggests the presence of local antiferromagnetic ordering in the spin-frustration system. Thermal decomposition of carbides holds the promise of being a technique to obtain a new class of wafer-scale functional epitaxial graphene for various applications.