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Araki, Shohei; Gunji, Satoshi; Arakaki, Yu; Murakami, Takahiko; Yoshikawa, Tomoki; Hasegawa, Kenta; Tada, Yuta; Izawa, Kazuhiko; Suyama, Kenya
Proceedings of 4th Reactor Physics Asia Conference (RPHA2023) (Internet), 4 Pages, 2023/10
To conduct integrated thermal power measurements for the performance test of the modified STACY, we re-analyzed the experimental data measured in the solution fuel STACY using the activation method. We validated its feasibility under the limited number of activation detectors. The re-analyzed results of the activation method by using MVP and PHITS with JENDL-4.0 indicated that the effect of the difference of the position between activation detectors was small enough, and the results agreed with that of the fission product analysis within almost 10%. It is conceivable that the activation method could be adopted instead of the fission product analysis.
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
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.
Miyamoto, Yuta; Uemura, Masaru*; Yoshikawa, Katsuhiro*; Ando, Seiji*
Reiwa-2-Nendo Koeki Zaidan Hojin Wakasawan Enerugi Kenkyu Senta kenkyu Nempo, 23, P. 40, 2021/10
no abstracts in English
Sato, Ikken; Arai, Yuta*; Yoshikawa, Shinji
Journal of Nuclear Science and Technology, 58(4), p.434 - 460, 2021/04
Times Cited Count:6 Percentile:70.8(Nuclear Science & Technology)Kaburagi, Masaaki; Shimazoe, Kenji*; Otaka, Yutaka*; Uenomachi, Mizuki*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*; et al.
Nuclear Instruments and Methods in Physics Research A, 971, p.164118_1 - 164118_8, 2020/08
Times Cited Count:7 Percentile:65.65(Instruments & Instrumentation)Miyamoto, Yuta; Iwai, Hiroki; Yoshikawa, Katsuhiro*
Wakasawan Enerugi Kenkyu Senta Homu Peji (Internet), 1 Pages, 2020/00
no abstracts in English
Ota, Yuki*; Sueki, Keisuke*; Sasa, Kimikazu*; Takahashi, Tsutomu*; Matsunaka, Tetsuya*; Matsumura, Masumi*; Tosaki, Yuki*; Honda, Maki*; Hosoya, Seiji*; Takano, Kenta*; et al.
JAEA-Conf 2018-002, p.99 - 102, 2019/02
no abstracts in English
Nakashima, Yosuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Oki, Kensuke*; Sakamoto, Mizuki*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; Imai, Tsuyoshi*; et al.
Journal of Nuclear Materials, 463, p.537 - 540, 2015/08
Times Cited Count:20 Percentile:83.66(Materials Science, Multidisciplinary)Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.
Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10
Chen, Y.*; Feng, X.*; Kasukabe, Yoshitaka*; Yamamoto, Shunya; Yoshikawa, Masahito; Fujino, Yutaka*
Journal of Alloys and Compounds, 577(Suppl.1), p.S18 - S24, 2013/11
Times Cited Count:2 Percentile:16.93(Chemistry, Physical)Epitaxial transformation processes of titanium films due to Nitrogen-implantation have been clarified through in-situ observations by using transmission electron microscope(TEM)and electron energy loss spectroscope, along with molecular orbital calculations. The N ions with 62 keV are implanted into as-deposited Ti films which consist of hcp-Ti and TiH with preferred orientations, in the 400 kV analytic high resolution TEM combined with ion accelerators at JAEA Takasaki. Thus, titanium nitride (TiN) films with preferred orientations are epitaxially formed by the inheritance of partial atomic arrangement of hcp-Ti or TiH in as-deposited Ti films and by the occupation of octahedral sites by N atoms, which elucidates that epitaxial transformation of hcp-fcc Ti sublattices occurs.
Kasukabe, Yoshitaka*; Shimoda, Hiroyuki*; Chen, Y.*; Yamamoto, Shunya; Yoshikawa, Masahito; Fujino, Yutaka*
Nuclear Instruments and Methods in Physics Research B, 315, p.131 - 135, 2013/11
Times Cited Count:1 Percentile:11.48(Instruments & Instrumentation)Epitaxial transformation phenomena of titanium films due to Nitrogen-implantation have been clarified through in-situ observations by using transmission electron microscope(TEM)and electron energy loss spectroscope (EELS), along with molecular orbital calculations. The N ions with 62 keV are implanted into as-deposited Ti films which consist of hcp-Ti and TiH with preferred orientations, in the 400 kV analytic high resolution TEM combined with ion accelerators at JAEA Takasaki. The result of EELS measurements indicates that the hcp-fcc transformation occurs preferentially above a critical concentration ratio, N/Ti 0.25. This means that above the N/Ti 0.25, the invasion of implanted N atom to the N-unoccupied octahedral site in the neighboring unit cell next to the N-occupied one in hcp-Ti occurs preferentially, and induces the growth of nucleus of the hcp-fcc transformation.
Kasukabe, Yoshitaka*; Chen, Y.*; Yamamoto, Shunya; Yoshikawa, Masahito; Fujino, Yutaka*
e-Journal of Surface Science and Nanotechnology (Internet), 9, p.191 - 198, 2011/04
The purpose of this work is to study changes of the crystallographic and electronic structures of Ti films by heating and by nitriding during N-implantation into Ti films, using in-situ transmission electron microscope equipped with the instrument for electron energy loss spectroscopy, and then to clarify the atomistic nitriding processes of Ti thin films due to the N-implantation with the aid of self-consistent charge discrete variational X molecular orbital calculations. It is clarified that the maximum concentration of N in Ti films during the N-implantation and the change of electronic structures near the fermi level, respectively, depend on the implantation temperature and the ratio of N/Ti in Ti films. Furthermore, taking into account the bonding interaction of Ti sublattices with ligand N atoms, the transformation mechanisms between hcp-Ti and fcc-Ti sublattices due to the implantation of N atoms are discussed.
Hashimoto, Takashi; Ishiyama, Hironobu*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari; Jeong, S.-C.*; Tanaka, Masahiko*; Yoshikawa, Nobuharu*; Nomura, Toru*; et al.
Physics Letters B, 674(4-5), p.276 - 280, 2009/04
Times Cited Count:7 Percentile:47.04(Astronomy & Astrophysics)The excitation function of the Li(d,t)Li reaction was directly measured using Li beams at E = 0.3, 0.4, 0.5, 0.7, 0.8, 1.0, 1.1, and 1.2 MeV with CD targets. The beam energies covered the Gamow peaks for 1310 K. Large cross sections were observed at around E = 0.8 MeV, implying a resonance state located at 22.4 MeV in Be. The present astrophysical reaction rate is higher in one order magnitude than the presently adopted rate at around 110 K.
Kasukabe, Yoshitaka*; Watanabe, Yohei*; Yamamoto, Shunya; Yoshikawa, Masahito; Fujino, Yutaka*
e-Journal of Surface Science and Nanotechnology (Internet), 7, p.625 - 632, 2009/04
Titanium nitrides (TiN) are non-stoichiometric compounds and show covalent properties as well as metallic and ionic properties, which make them fascinating for both fundamental research and technological applications. The purpose of this work is to study changes of the crystallographic and electronic structures of Ti films by heating and by nitriding during N-implantation into Ti films separated from NaCl(001) substrates, using in-situ transmission electron microscope (TEM) equipped with the instrument for electron energy loss spectroscopy (EELS), and then to clarify the atomistic nitriding processes of Ti thin films due to the N-implantation with the aid of molecular orbital calculations. The present calculations throw light on the hcp-fcc transformation mechanism between fcc-Ti sublattices and hcp sublattices due to the release of H atoms or due to the implantation of N atoms, taking into account the bonding interaction of Ti sublattices with ligand H or N atoms.
Kasukabe, Yoshitaka*; Nishida, Shinsaku*; Yamamoto, Shunya; Yoshikawa, Masahito; Fujino, Yutaka*
Applied Surface Science, 254(23), p.7942 - 7946, 2008/09
Times Cited Count:8 Percentile:37.23(Chemistry, Physical)In order to clarify atomistic growth processes of TiN films due to ion implantation, in-situ observations by using transmission electron microscope and electron energy loss spectroscope at JAEA-Takasaki have been carried out, along with composition analysis and with the characterization of the electronic structure by molecular orbital calculation. The characterization of electronic structure of Ti films before and after implantation indicates that octahedral sites of hcp-Ti with larger space have higher electron density, which leads to the invasion of implanted ions into octahedral sites, and that the hcp-fcc transformation is induced by the shear in 010 direction on (001) plane, promoted by the forming of -type covalent bonds mainly consisted of hybridized orbitals due to combination of Ti3d and N2p, and by the weakening of Ti-Ti bonds.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*; Mitamura, Muneki*; et al.
Journal of Environmental Radioactivity, 99(1), p.211 - 217, 2008/01
Times Cited Count:19 Percentile:40.36(Environmental Sciences)In a sediment core of Nishiyama reservoir at Nagasaki, depth profiles of Pu/Pu ratio, Pu and Cs concentrations were determined. Sediments containing plutonium and Cs, which were fallout deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout. This is the first entire depositional records of plutonium and Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
Journal of Radioanalytical and Nuclear Chemistry, 273(1), p.183 - 186, 2007/07
Times Cited Count:7 Percentile:47.2(Chemistry, Analytical)no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*
Journal of Geosciences, Osaka City University, 50, p.7 - 13, 2007/03
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
KEK Proceedings 2006-5, p.36 - 40, 2006/11
no abstracts in English
Ishiyama, Hironobu*; Hashimoto, Takashi; Ishikawa, Tomoko*; Watanabe, Yutaka*; Das, S. K.*; Miyatake, Hiroari; Mizoi, Yutaka*; Fukuda, Tomokazu*; Tanaka, Masahiko*; Fuchi, Yoshihide*; et al.
Physics Letters B, 640(3), p.82 - 85, 2006/09
Times Cited Count:33 Percentile:84.88(Astronomy & Astrophysics)The excitation function of the Li(,n)B reaction was measured while identifying the final state event by event in the region of E = 0.7 - 2.6 MeV using a highly efficient detector system and a low-energy Li beam. The results are much improved both in statistics and precisions, and show smaller cross sections than those of previous measurements by a factor of more than 2 in the low-energy region of E 1.5 MeV. A resonance-like structure is found at around E = 0.85 MeV.