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Terasaka, Yuta; Iimoto, Takeshi*; Saso, Michitaka*; Fujita, Reiko*
Nihon Genshiryoku Gakkai-Shi ATOMO, 66(4), p.203 - 207, 2024/04
no abstracts in English
Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Kim, S.; Nanamura, Takuya; Sako, Hiroyuki; Tamura, Hirokazu; Yamamoto, Takeshi; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(12), p.123D01_1 - 123D01_17, 2022/12
Times Cited Count:0 Percentile:0.01(Physics, Multidisciplinary)Yamamoto, Takeshi; Fujita, Manami; Gogami, Toshiyuki*; Harada, Takeshi*; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Ishikawa, Yuji*; Kamata, K.*; Kanauchi, H.*; et al.
EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11
Fujita, Manami; Hosomi, Kenji; Ishikawa, Yuji*; Kanauchi, H.*; Koike, Takeshi*; Ogura, Yu*; Tamura, Hirokazu; Tanida, Kiyoshi; Ukai, Mifuyu*; Yamamoto, Takeshi
Nuclear Instruments and Methods in Physics Research A, 1042, p.167439_1 - 167439_9, 2022/11
Times Cited Count:2 Percentile:53.91(Instruments & Instrumentation)Nanamura, Takuya; Fujita, Manami; Hasegawa, Shoichi; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Naruki, Megumi; Sato, Susumu; Sako, Hiroyuki; Tamura, Hirokazu; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(9), p.093D01_1 - 093D01_35, 2022/09
Times Cited Count:5 Percentile:67.44(Physics, Multidisciplinary)Hokama, Tomonori; Fujita, Hiroki; Nakano, Masanao; Iimoto, Takeshi*
Radiation Protection Dosimetry, 196(3-4), p.136 - 140, 2021/11
Times Cited Count:0 Percentile:0.01(Environmental Sciences)During the early phase of a nuclear accident, major radioactive materials are released into the environment, necessitating the prompt deployment of various protective actions to avoid or reduce radiation exposure. To implement these actions, the levels of radioactivity in the environment should be determined. However, the radioactivity concentrations of artificial alpha-particle-emitting radionuclides such as plutonium are difficult to measure in airborne samples, because they are interfered with natural radionuclides such as uranium decay products. Therefore, chemical separation is required to measure the concentrations. This study presents a new emergency monitoring system for airborne samples, which performs multiple-pulse time-interval analysis (MTA) without chemical separation. The system is used in conjunction with an alpha/beta-particle survey meter and adopted an analysis method focusing on the detected time interval of each particle. Its features are that a short time to output measurement result, easy handling and nondestructive. The estimated detection limit of the system was 9.510 Bq m. The MTA-based monitoring system could be useful in situations requiring prompt measurement and screening of samples.
Miwa, Koji*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; et al.
Physical Review C, 104(4), p.045204_1 - 045204_20, 2021/10
Times Cited Count:12 Percentile:89.15(Physics, Nuclear)Yoshimoto, Masahiro*; Fujita, Manami; Hashimoto, Tadashi; Hayakawa, Shuhei; Ichikawa, Yudai; Ichikawa, Masaya; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.
Progress of Theoretical and Experimental Physics (Internet), 2021(7), p.073D02_1 - 073D02_19, 2021/07
Times Cited Count:13 Percentile:81.3(Physics, Multidisciplinary)Yoshida, Junya; Akaishi, Takaya; Fujita, Manami; Hasegawa, Shoichi; Hashimoto, Tadashi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Kim, S.; et al.
JPS Conference Proceedings (Internet), 33, p.011112_1 - 011112_8, 2021/03
Sakao, Tamao*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.
JPS Conference Proceedings (Internet), 33, p.011133_1 - 011133_6, 2021/03
Hayakawa, Shuhei; Fujita, Manami; Hasegawa, Shoichi; Hashimoto, Tadashi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.
Physical Review Letters, 126(6), p.062501_1 - 062501_6, 2021/02
Times Cited Count:34 Percentile:95.34(Physics, Multidisciplinary)Gogami, Toshiyuki*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Imai, Kenichi*; Ichikawa, Yudai; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; et al.
Journal of Physics; Conference Series, 1643, p.012133_1 - 012133_6, 2020/12
Times Cited Count:2 Percentile:84.57(Astronomy & Astrophysics)Miwa, Koji*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.
Journal of Physics; Conference Series, 1643, p.012174_1 - 012174_6, 2020/12
Times Cited Count:2 Percentile:84.57(Astronomy & Astrophysics)Nakane, Tomohiro*; Yoneyama, Shota*; Kodama, Takeshi*; Kikuchi, Koichi*; Nakao, Akiko*; Ohara, Takashi; Higashinaka, Ryuji*; Matsuda, Tatsuma*; Aoki, Yuji*; Fujita, Wataru*
Dalton Transactions (Internet), 48(1), p.333 - 338, 2019/01
Times Cited Count:2 Percentile:11.34(Chemistry, Inorganic & Nuclear)Yamaguchi, Hisato*; Ogawa, Shuichi*; Watanabe, Daiki*; Hozumi, Hideaki*; Gao, Y.*; Eda, Goki*; Mattevi, C.*; Fujita, Takeshi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; et al.
Physica Status Solidi (A), 213(9), p.2380 - 2386, 2016/09
Times Cited Count:13 Percentile:52.49(Materials Science, Multidisciplinary)We report valence-band electronic structure evolution of graphene oxide (GO) upon its thermal reduction. The degree of oxygen functionalization was controlled by annealing temperature, and an electronic structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in the density of states around the Fermi level upon thermal annealing at 600C. The result indicates that while there is an apparent bandgap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of bandgap closure was correlated with the electrical, chemical, and structural properties to determine a set of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of 500C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to an as-synthesized counterpart.
Hama, Katsuhiro; Sasao, Eiji; Iwatsuki, Teruki; Onoe, Hironori; Sato, Toshinori; Fujita, Tomoo; Sasamoto, Hiroshi; Matsuoka, Toshiyuki; Takeda, Masaki; Aoyagi, Kazuhei; et al.
JAEA-Review 2016-014, 274 Pages, 2016/08
We synthesized the research results from the Mizunami/Horonobe Underground Research Laboratories (URLs) and geo-stability projects in the second midterm research phase. This report can be used as a technical basis for the Nuclear Waste Management Organization of Japan/Regulator at each decision point from siting to beginning of disposal (Principal Investigation to Detailed Investigation Phase).
Fujita, Hiroe*; Yuyama, Kenta*; Li, X.*; Hatano, Yuji*; Toyama, Takeshi*; Ota, Masayuki; Ochiai, Kentaro; Yoshida, Naoaki*; Chikada, Takumi*; Oya, Yasuhisa*
Physica Scripta, 2016(T167), p.014068_1 - 014068_5, 2016/02
Times Cited Count:33 Percentile:82.89(Physics, Multidisciplinary)The irradiation defects were introduced by Fe irradiation, fission neutron irradiation and D-T neutron irradiation. After the irradiation, the deuterium ions (D) implantation was performed and the D retention behavior was evaluated by thermal desorption spectroscopy. The experimental results indicated that dense vacancies and voids within the shallow region near the surface were introduced by Fe irradiation. The trapping state of D by vacancies and void were clearly controlled by the damage concentration and the voids would become the most stable D trapping site. For fission neutron irradiated W, most of the D was adsorbed on the surface and/or trapped by dislocation loops and no vacancies and voids for D trapping due to its lower damage concentration. D trapping by vacancies were found in the bulk of D-T neutron irradiated W, indicating that the neutron energy distribution could make a large impact on irradiation defect formation and the D retention behavior.
Hama, Katsuhiro; Mizuno, Takashi; Sasao, Eiji; Iwatsuki, Teruki; Saegusa, Hiromitsu; Sato, Toshinori; Fujita, Tomoo; Sasamoto, Hiroshi; Matsuoka, Toshiyuki; Yokota, Hideharu; et al.
JAEA-Research 2015-007, 269 Pages, 2015/08
We have synthesised the research results from Mizunami/Horonobe URLs and geo-stability projects in the second mid-term research phase. It could be used as technical bases for NUMO/Regulator in each decision point from sitting to beginning of disposal (Principal Investigation to Detailed Investigation Phase). High quality construction techniques and field investigation methods have been developed and implemented and these will be directly applicable to the National Disposal Program (along with general assessments of hazardous natural events and processes). It will be crucial to acquire technical knowledge on decisions of partial backfilling and final closure by actual field experiments in Mizunami/Horonobe URLs as main themes for the next phases.
Fujita, Natsuko; Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi
Materials Science Forum, 778-780, p.1042 - 1045, 2014/02
Times Cited Count:1 Percentile:53.76(Crystallography)A Silicon Carbide (SiC) dosimeter has been exposed to -rays emitted from a Co source in order to test the response of radiation-induced current in the dose rate ranging from 0.4 Gy/h to 4 kGy/h. The SiC dosimeter in this study is a high purity semi-insulating 4H-SiC with nickel and aluminum electrode. The radiation-induced currents in the dosimeter show a linear relationship with the dose rate, and are repeatable and stable.
Iwamoto, Naoya; Onoda, Shinobu; Fujita, Natsuko; Makino, Takahiro; Oshima, Takeshi
Materials Science Forum, 778-780, p.289 - 292, 2014/02
Times Cited Count:0 Percentile:0.32(Crystallography)