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Gomi, Yuibi*; Takami, Kazusa*; Mizuno, Rurie*; Niikura, Megumi*; Yasuda, Ryuichi*; Deng, Y.*; Kawase, Shoichiro*; Watanabe, Yukinobu*; Abe, Shinichiro; Liao, W.*; et al.
IEEE Transactions on Nuclear Science, 72(8), p.2751 - 2762, 2025/08
Times Cited Count：2 Percentile：54.69(Engineering, Electrical & Electronic)The study of muon-induced soft errors in terrestrial settings remains underexplored even though the incidence of muon-induced soft errors tends to increas. In this study, we conducted positive and negative muon irradiation experiments on four types of 12-nm FinFET SRAMs. At the momentum where the SEU cross section peaks, 2-fin cells exhibit larger SEU cross sections than 1-fin cells for negative muons. Conversely, for positive muons, the SEU cross section is larger in 1-fin cells than in 2-fin cells due to the increased diffusion capacitance in 2-fin cells. We also performed the Monte Carlo simulations. The results suggest that a single sensitive volume with the same critical charge value cannot consistently reproduce the SEU cross sections for both types of muons.
Uno, Koichiro*; Okumura, Masahiko; Nakao, Atsushi*; Yamaguchi, Akiko; Yanai, Junta*
Science of the Total Environment, 949, p.175012_1 - 175012_8, 2024/11
Times Cited Count：4 Percentile：38.97(Environmental Sciences)Frayed edge sites (FES), formed by the partial weathering of mica minerals, selectively adsorb Cs ions. However, the detailed mechanism of this adsorption has not been fully clarified. In this study, cation extraction and Cs adsorption experiments were conducted on mica. It was found that potassium-adsorbed mica adsorbed more Cs than rubidium-adsorbed mica. To elucidate the cause of this, the stability of Cs, rubidium, and potassium adsorbed on FES was evaluated using first-principles calculations. It was determined that the presence of potassium as the cation species prior to Cs adsorption is important for the stability of Cs on the FES.
values calculated from radiocesium interception potentialUno, Koichiro*; Nakao, Atsushi*; Okumura, Masahiko; Yamaguchi, Akiko; Kogure, Toshihiro*; Yanai, Junta*
Nihon Dojo Hiryo Gaku Zasshi, 94(5), p.376 - 384, 2023/10
Radiocesium interception potential (RIP) has been widely used as a quantitative indicator of cesium (Cs) adsorption capacity of soil, but it has been found that RIP does not always correlate with the distribution coefficient () of Cs in the actual environment. In order to clarify the cause of this discrepancy, we measured Kd using more realistic solutions, compared it with RIP, and evaluated the mineral structure. As a result, it was found that the concentration of competing cations, such as potassium and ammonium ions, and the structural change of the mineral itself are important.
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08
Times Cited Count：4 Percentile：22.33(Engineering, Electrical & Electronic)A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.
X raysOkumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07
Times Cited Count：23 Percentile：77.87(Physics, Multidisciplinary)We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic 
and 
X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the 
-shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.
state of 
Al; Investigation on the neutron 
excitation across 
in the island of inversionXu, Z. Y.*; Heylen, H.*; Asahi, Koichiro*; Boulay, F.*; Daugas, J. M.*; de Groote, R. P.*; Gins, W.*; Kamalou, O.*; Koszor
s, 
.*; Lykiardopoupou, M.*; et al.
Physics Letters B, 782, p.619 - 626, 2018/07
Times Cited Count：8 Percentile：49.75(Astronomy & Astrophysics)no abstracts in English
=20 shell in 
Al investigated through the ground-state electric quadrupole momentShimada, Kenji*; Ueno, Hideki*; Neyens, G.*; Asahi, Koichiro*; Balabanski, D. L.*; Daugas, J. M.*; Depuydt, M.*; De Rydt, M.*; Gaudefroy, L.*; Gr
vy, S.*; et al.
Physics Letters B, 714(2-5), p.246 - 250, 2012/08
Times Cited Count：8 Percentile：42.29(Astronomy & Astrophysics)no abstracts in English
Umeda, Naotaka; Mizuno, Takatoshi; Taniguchi, Masaki; Kashiwagi, Mieko; Ezato, Koichiro; Tobari, Hiroyuki; Dairaku, Masayuki; Watanabe, Kazuhiro; Sakamoto, Keishi; Inoue, Takashi
Journal of Plasma and Fusion Research SERIES, Vol.9, p.259 - 263, 2010/08
Long pulse acceleration of ITER class H
ion beam has carried out at MeV accelerator. Melts of the acceleration grids were found around grid apertures. To accelerate higher power beam, compensation of the beam deflection and design of a new grid which has high cooling performance is required. In this study, 3D thermal transport analysis was carried out and a new acceleration grid was designed. From the analysis, it was found that the grid temperature exceeded the melting point in a few seconds. To overcome this problem, a new acceleration grid was designed whose cooling channel was drilled near upper surface. This countermeasure is effective not only to reduce the temperature rise but to enlarge the aperture size from 14 mm to 16 mm. From the result of heat analysis, temperature rise of the new grid is greatly reduced than that of the previous grid. It is expected that higher power and longer pulse beam would be accelerated at next test campaign.
Al and determination of the effective proton charge in the sd-shellDe Rydt, M.*; Neyens, G.*; Asahi, Koichiro*; Balabanski, D. L.*; Daugas, J. M.*; Depuydt, M.*; Gaudefroy, L.*; Grvy, S.*; Hasama, Yuka*; Ichikawa, Yuichi*; et al.
Physics Letters B, 678(4), p.344 - 349, 2009/07
Times Cited Count：18 Percentile：69.55(Astronomy & Astrophysics)no abstracts in English
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
no abstracts in English
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
Times Cited Count：7 Percentile：21.99(Physics, Fluids & Plasmas)no abstracts in English
Tsunematsu, Toshihide; Seki, Masahiro; Tsuji, Hiroshi; Okuno, Kiyoshi; Kato, Takashi; Shibanuma, Kiyoshi; Hanada, Masaya; Watanabe, Kazuhiro; Sakamoto, Keishi; Imai, Tsuyoshi; et al.
Fusion Science and Technology, 42(1), p.75 - 93, 2002/07
Times Cited Count：1 Percentile：9.51(Nuclear Science & Technology)Japanese contributions to ITER Engineering Design Activity are presented, together with an introduction of the objectives and design of the ITER whose program have been carried out through the international collaboration by EU, Japan, Russian Federation and the USA. New technologies have been produced through the development, fabrication and testing of scalable models in the fields of superconducting magnet, reactor structure with vacuum vessel, high-heat-flux plasma facing component, neutral beam injector, high-power mm-wave generator and so on. As major contributions from Japan, development and testing results of a 13-T, 640-MJ, Nb
Sn pulsed magnet, a 18-degree sector of vacuum vessel with a height of 15 m and a width of 9 m, CFC armors to CuCrZr cooling tube that withstood 20 MW/m
, a 31 mA/cm negative ion beam source, a 1-MeV beam-accelerator, a 1-MW 170-GHz gyrotron were described.
Okano, Masanori; Kuno, Takehiko; Watahiki, Masaru; Yamada, Keiji; Kurakata, Koichiro
no journal, ,
no abstracts in English
Uno, Koichiro*; Nakao, Atsushi*; Okumura, Masahiko; Kogure, Toshihiro*; Wagai, Rota*; Yamaguchi, Akiko; Yanai, Junta*
no journal, ,
no abstracts in English
Uno, Koichiro*; Nakao, Atsushi*; Okumura, Masahiko; Kogure, Toshihiro*; Yamaguchi, Akiko; Takeda, Hikaru*; Maruyama, Hayato*; Shinano, Takuro*; Yanai, Junta*
no journal, ,
Biotite inhibits radiocesium (RCs) transfer from soil to plants by two functions of selective adsorption of radiocesium (Cs) between layers (Cs adsorption ability) and K supply from between layers (K supply ability). However, it was difficult to distinguish between the two. In this study, the authors succeeded in preparing biotite in which both functions are variously different by preparing weathered biotite in which interlayer pottasium (K) was replaced with rubidium (Rb) to lose K supply ability. By systematically comparing these biotites, the authors clarified the effects of Cs adsorption ability and K supply ability on Cs transfer to plants.
