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Watabe, Hiroshi*; Sato, Tatsuhiko; Yu, K. N.*; Zivkovic, M.*; Krstic, D.*; Nikezic, D.*; Kim, K. M.*; Yamaya, Taiga*; Kawachi, Naoki*; Tanaka, Hiroki*; et al.
Radiation Protection Dosimetry, 13 Pages, 2023/00
Times Cited Count:0 Percentile:0.01(Environmental Sciences)Previously, we have developed DynamicMC for modelling relative movement of ORNL phantom in a radiation field for MCNP. Using this software, 3-dimensional dose distributions in a phantom irradiated by a certain mono-energetic source can be deduced through its graphical user interface (GUI). In this study, we extended DynamicMC to be used in combination with the PHITS by providing it with a higher flexibility for dynamic movement for a less sophisticated anthropomorphic phantom. We anticipate that the present work and the developed open-source tools will be in the interest of nuclear radiation physics community for research and teaching purposes.
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)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)Ishikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.
Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05
Times Cited Count:4 Percentile:45.12(Physics, Nuclear)Yokoi, Naoto*; Sato, Koji*; Saito, Eiji
Physical Review D, 100(10), p.106012_1 - 106012_9, 2019/11
Times Cited Count:2 Percentile:13.91(Astronomy & Astrophysics)Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*
Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11
The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above 0.2-0.3 MeV/nucleon for A=2030 amu; the PKA mass identification thresholds decrease to 0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.
Miwa, Koji*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Imai, Kenichi; Kondo, Yasuhiro; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; et al.
JPS Conference Proceedings (Internet), 17, p.041002_1 - 041002_6, 2017/07
Hou, D.*; Qiu, Z.*; Barker, J.*; Sato, Koji*; Yamamoto, Kei; Vlez, S.*; Gomez-Perez, J. M.*; Hueso, L. E.*; Casanova, F.*; Saito, Eiji
Physical Review Letters, 118(14), p.147202_1 - 147202_6, 2017/04
Times Cited Count:109 Percentile:97.22(Physics, Multidisciplinary)Qiu, Z.*; Li, J.*; Hou, D.*; Arenholz, E.*; N'Diaye, A. T.*; Tan, A.*; Uchida, Kenichi*; Sato, Koji*; Okamoto, Satoshi*; Tserkovnyak, Y.*; et al.
Nature Communications (Internet), 7, p.12670_1 - 12670_6, 2016/08
Times Cited Count:141 Percentile:97.14(Multidisciplinary Sciences)Hou, D.*; Qiu, Z.*; Iguchi, Ryo*; Sato, Koji*; Vehstedt, E. K.*; Uchida, Kenichi*; Bauer, G. E. W.*; Saito, Eiji
Nature Communications (Internet), 7, p.12265_1 - 12265_6, 2016/07
Times Cited Count:13 Percentile:64.47(Multidisciplinary Sciences)Yokoi, Naoto*; Ishihara, Masafumi*; Sato, Koji*; Saito, Eiji
Physical Review D, 93(2), p.026002_1 - 026002_6, 2016/01
Times Cited Count:16 Percentile:60.37(Astronomy & Astrophysics)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.
Sato, Koji; Yanagisawa, Tsutomu*
Nihon Genshiryoku Gakkai-Shi ATOMO, 56(4), p.271 - 276, 2014/04
This article introduces the trend of nuclear power development of India, in which the current energy and electric power situation, the nuclear energy policy (historical background, nuclear development organization, three-stage nuclear power development program, introduction plan of electric power and nuclear power, and interantional cooperation), current status of nuclear development (first phase: thermal neutron reactors (pressurized heavy-water reactors (PHWR) and light water reactors (LWR)) and related fuel cycle, secondary stage: fast reactors and related fuel cycle, third stage: advanced reactors and related fuel cycle, development of human resources, influence of the TEPCO's Fukushima Dai-ichi Nuclear Power Station accident, and the expectation for nuclear cooperation are described.
Iguchi, Ryo*; Sato, Koji*; Hirobe, Daichi*; Daimon, Shunsuke*; Saito, Eiji
Applied Physics Express, 7(1), p.013003_1 - 013003_4, 2014/01
We investigate a dc rectification effect of magnetization dynamics based on spin Hall magnetoresistance (SMR) in an insulating magnet/metal system on spin pumping measurements. We theoretically find that the rectification effect by SMR has different in-plane magnetization angle dependence from that of the inverse spin Hall effect on the spin pumping. The negligible contribution from the rectification effect is experimentally confirmed in a cavity measurement.
Iguchi, Ryo*; Sato, Koji*; Hirobe, Daichi*; Daimon, Shunsuke*; Saito, Eiji
Applied Physics Express, 7(1), p.013003_1 - 013003_4, 2014/01
Times Cited Count:21 Percentile:65.2(Physics, Applied)Yamada, Junya; Seya, Natsumi; Haba, Risa; Muto, Yasunobu; Numari, Hideyuki*; Sato, Naomitsu*; Nemoto, Koji*; Takasaki, Hiroichi*; Shimizu, Takehiko; Takasaki, Koji
JAEA-Data/Code 2013-006, 100 Pages, 2013/06
This report presents the results of emergency radiation monitoring, including ambient -ray dose rate, atmospheric radioactivity, meteorological observation and estimation of internal exposure resulting from the accident at the Fukushima Daiichi Nuclear Power Plant triggered by the earthquake off the pacific coast of Tohoku on 11th March 2011, conducted by Oarai Research and Development Center (ORDC), Japan Atomic Energy Agency (JAEA) from March to May, 2011. ORDC is located in the central part of Ibaraki prefecture and approximately 130 km southwest of the Fukushima Daiichi Nuclear Power Plant. From around 15th to 21st March, 2011, the ambient -ray dose rate increased and many radioactive nuclides were detected in the atmosphere.
Oshima, Takeshi; Sato, Shinichiro; Imaizumi, Mitsuru*; Nakamura, Tetsuya*; Sugaya, Takeyoshi*; Matsubara, Koji*; Niki, Shigeru*
Solar Energy Materials and Solar Cells, 108, p.263 - 268, 2013/01
Times Cited Count:13 Percentile:49.45(Energy & Fuels)GaAs solar cells which have a PiN structure with 50 self-organized InGaAs Quantum Dot (QD) layers were irradiated with 1 MeV electrons up to 110 /cm. After irradiation at 110/cm, the remaining factor of I, V and P for the InGaAs 50 QD solar cell becomes 80, 90 and 55% of the initial values, respectively. On the other hand, those values for non QD GaAs solar cells decrease to 95, 80 and 63% of the initial values, respectively. Since the i-layer for the 50 QD solar cells (1.1 m) is thicker than the non QD solar cells (660 nm), the larger degradation of I for the 50 QD solar cells than the non QD ones can be interpreted in terms that the carrier recombination in the i-layer for the 50 QD solar cells is larger than that for the non QD solar cells. For V, the 50 QD solar cells showes better radiation resistance than the non QD solar cells. Furthermore, the annealing behavior of the electrical characteristics for the 50 QD and the non QD solar cells was investigated at RT under AM 0 immediately after the irradiation. As a result, the recovery of the electrical characteristics for both solar cells was observed, and the GaAs solar cells shows relatively larger recovery compared to the 50 QD solar cells. Although the mechanism of this recovery has not yet been clarified, the origin of this recovery is thought not to come from the existence of QDs because the GaAs solar cell without QD layers also shows the recovery.
Sato, Koji; Kotake, Shoji; Fujita, Yuji; Mizuno, Tomoyasu
Energy Procedia, 7, p.140 - 145, 2011/09
Times Cited Count:3 Percentile:89.42(Nuclear Science & Technology)JAEA has been implementing the FaCT project in cooperation with electric utilities toward the commercialization of fast reactor cycle system before 2050. In this FaCT project, many innovative technologies with technical challenges are actively used in order to provide significant improvements in economic competitiveness, enhancement of safety and reliability, sustainability, and nonproliferation. The work of deciding on the adoption of innovative technologies by the end of JFY2010 is in progress. This paper describes current preliminary assessment results.
Sato, Koji
Genshiryoku eye, 56(3), p.20 - 25, 2010/03
International Conference on "Fast Reactors and Related Fuel Cycles; Challenges and Opportunities" (FR09) organized by the IAEA and hosted by the JAEA was held on December 2009 in Kyoto and Tsuruga. The conference is summarized in this report.
Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.
Materials Science Forum, 607, p.248 - 250, 2009/00
So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring the equivalency and reliability of data from different laboratories. As a first, we conducted an interlaboratory comparison of PAL measurements for metal, polymer and silica glass with agreed procedures for data recording and analysis. The PAL data recorded at different laboratories were analyzed with a single lifetime component for the metal sample and with three components for the others, respectively. Based on the results of the reported positron and ortho-positronium lifetimes, the possible sources of the uncertainties in the PAL measurements are discussed. To reduce the effect of scattered rays, a lead shield was placed between the detectors. The uncertainty was significantly decreased, signifying that placing lead shields between the detectors effectively reduced the false signals due to the scattered rays.