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Maeyama, Shinya*; Watanabe, Tomohiko*; Nakata, Motoki*; Nunami, Masanori*; Asahi, Yuichi; Ishizawa, Akihiro*
Nature Communications (Internet), 13, p.3166_1 - 3166_8, 2022/06
Times Cited Count：14 Percentile：93.39(Multidisciplinary Sciences)Turbulent transport is a key physics process for confining magnetic fusion plasma. Recent theoretical and experimental studies of existing fusion experimental devices revealed the existence of cross-scale interactions between small (electron)-scale and large (ion)-scale turbulence. Since conventional turbulent transport modelling lacks cross-scale interactions, it should be clarified whether cross-scale interactions are needed to be considered in future experiments on burning plasma, whose high electron temperature is sustained with fusion-born alpha particle heating. Here, we present supercomputer simulations showing that electron scale turbulence in high electron temperature plasma can affect the turbulent transport of not only electrons but also fuels and ash. Electron-scale turbulence disturbs the trajectories of resonant electrons responsible for ion-scale micro-instability and suppresses large-scale turbulent fluctuations. Simultaneously, ion-scale turbulent eddies also suppress electron-scale turbulence. These results indicate a mutually exclusive nature of turbulence with disparate scales. We demonstrate the possibility of reduced heat flux via cross-scale interactions.
Miura, Yukitoshi
RIST News, (61), p.1 - 2, 2016/07
no abstracts in English
Tsuda, Shuichi; Saito, Kimiaki
"Fukushima No Fukko Ni Mukete No Hoshasen Ni Kansuru Korekara No Kadai" Shimpojiumu Hokokusho, p.30 - 33, 2015/00
Dose rate monitoring in air in the environment has been performed since the Fukushima Dai-ichi Nuclear Power Plant accident happened. The reliability of detectors such as survey-meters is ensured under a controlled set of standard conditions in a radiation calibration field. However, the calibration is performed only in a uniform irradiation condition in general, but in reality, the incident direction of the photons is random in the environment. Since detector responses are dependent on incident direction, except for spherical detectors, it is necessary to evaluate the reliability of the measured dose. In this study, using the PHITS code, dose rates in air of a common NaI(Tl) scintillation survey-meter and CsI(Tl) detectors used in the KURAMA system are calculated in a semi-infinite radiation field. In the presentation, the dependence of the dose rates on the incident direction of photons will be shown.
in consideration of whole-body movementsSoh, Zu*; Suzuki, Michiyo; Kurita, Yuichi*; Tsuji, Toshio*
Proceedings of SAI Intelligent Systems Conference 2015 (IntelliSys 2015), p.651 - 656, 2015/00
Miyamura, Hiroko; Kawamura, Takuma; Suzuki, Yoshio; Idomura, Yasuhiro; Takemiya, Hiroshi
Joho Shori Gakkai Rombunshi, 55(9), p.2216 - 2224, 2014/09
In numerical simulations, variations of calculation results with respect to a variable axis are often observed. When the target model is given in 3D, the simulation results become 4D. Such a multi-dimensional dataset given in more than 4D space is analyzed by detailed explorations of regions of interest (ROIs) in multi-dimensional space. However, for high-dimensional and large-scale datasets, this approach requires enormous processing time and effort, and may have difficulty in capturing all the ROIs. Therefore, we propose a technique that is based on a concept of spatiotemporal image. In our technique, a space axis is created by octree, a variable axis is defined in the direction perpendicular to the space axis. Our technique is applied to the results of 3D seismic simulations of a nuclear plant, and regions with characteristic frequency responses of each region are analyzed. Through the analyses, it is demonstrated that our technique can effectively capture ROIs from 4D datasets.
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Satake, Shinichi*
Proceedings of International Conference on Jets, Wakes and Separated Flows (ICJWSF 2005), p.137 - 144, 2005/11
no abstracts in English
Ueshima, Yutaka
i-Net, (13), p.6 - 9, 2005/05
no abstracts in English
Maesako, Hiroshi*; Suzuki, Yoshio; Aoyagi, Tetsuo; Nakajima, Norihiro
Fujitsu, 55(2), p.109 - 115, 2004/03
ITBL (Information Technology Based Laboratory) project is promoted under the "e-Japan national priority program" by six research institutions. The project aims to construct a virtual laboratory which aid collaborative studies amongst researchers by allowing for sharing of intellectual properties and resources such as supercomputer hardware, software, data, etc. In order to realize this virtual laboratory environment, the Japan Atomic Energy Research Institute is developing an ITBL system infrastructure software system. Some of the highlighted functions offered by the ITBL infrastructure are: authentication for connecting to the supercomputers, parallel and distributed communication, job execution on the connected supercomputers, and formation of communities for aiding communication amongst researchers. In this passage, besides the introduction of the ITBL infrastructure, a brief introduction of the Quantum Bioinformatics and the Numerical Environmental Systems will be given as examples of the applications developed on the ITBL infrastructure.
Sato, Minoru; Matsuda, Toshiaki
Heisei-15-Nendo Koenerugi Kasokuki Kenkyu Kiko Gijutsu Kenkyukai Hokokushu (CD-ROM), 3 Pages, 2004/00
no abstracts in English
Yonezawa, Chushiro; Matsue, Hideaki; Miyamoto, Yutaka; Suzuki, Daisuke; Yasuda, Kenichiro; Inagawa, Jun; Saito, Yoko
Jitsuyo Gamma-sen Sokutei Handobukku, 366 Pages, 2002/06
no abstracts in English
Mizuhashi, Kiyoshi; Uno, Sadanori; Chiba, Atsuya; Kitchen, R. L.*; Takada, Isao; Tajima, Satoshi
JNC TN7200 2001-001, p.80 - 83, 2002/01
no abstracts in English
Fukumoto, Ichiro; Omura, Etsuji*
Seimitsu Kogakkai-Shi, 67(6), p.916 - 921, 2001/06
no abstracts in English
Tani, Keiji
Dai-49-Kai Riron Oyo Rikigaku Koenkai Koen Rombunshu, p.313 - 316, 2001/00
no abstracts in English
Arai, Hidehiko
Denki Gakkai Gijutsu Hokoku, (810), p.56 - 58, 2000/10
no abstracts in English
Furukawa, Jun*; Nakanishi, Tomoko*; Matsubayashi, Masahito
Kashika Joho Gakkai-Shi, 20(suppl.1), p.377 - 380, 2000/07
no abstracts in English
Hayashi, Mitsuhiko*; Takai, Shigeomi*; Sakaguchi, Hiroki*; Matsubayashi, Masahito; Esaka, Takao*
Kashika Joho Gakkai-Shi, 20(suppl.1), p.375 - 376, 2000/07
no abstracts in English
Sakaguchi, Hiroki*; Hatakeyama, Keisuke*; Satake, Yuichi*; Fujine, Shigenori*; Yoneda, Kenji*; Kanda, Keiji*; Matsubayashi, Masahito; Esaka, Takao*
Kashika Joho Gakkai-Shi, 20(suppl.1), p.373 - 374, 2000/07
no abstracts in English
Tozawa, Katsuhiro; ; Kakehi, Isao
JNC TN9400 2000-052, 110 Pages, 2000/04
JNC-TN9400-2000-052.pdf:4.39MB
This report describes accomplishment of development of a cathode processor calculation code to simulate the mass and heat transfer phenomena with the distillation process and development of an analytical model for cooling behavior of the pyrochemical process cell on personal computers. The pyrochemical process using molten salt electrorefining would introduce new technologies for new fuels of particle oxide, particle nitride and metallic fuels. The cathode processor calculation code with distillation process was developed. A code validation calculation has been conducted on the basis of the benchmark problem for natural convection in a square cavity. Results by using the present code agreed well for the velocity-temperature fields, the maximum velocity and its location with the benchmark solution published in a paper. The functions have been added to advance the reality in simulation and to increase the efficiency in utilization. The test run has been conducted using the code with the above modification for an axisymmetric enclosed vessel simulating a cathode processor, and the capability of the distillation process simulation with the code has been confirmed. An analytical model for cooling behavior of the pyrochemical process cell was developed. The analytical model was selected by comparing benchmark analysis with detailed analysis on engineering workstation. Flow and temperature distributions were confirmed by the result of steady state analysis. In the result of transient cooling analysis, an initial transient peak of temperature occurred at balanced heat condition in the steady-state analysis. Final gas temperature distribution was dependent on gas circulation flow in transient condition. Then there were different final gas temperature distributions on the basis of the result of steady-state analysis. This phenomenon has a potential for it's own metastable condition. Therefore it was necessary to design gas cooling flow pattern without ...
Yokokawa, Mitsuo; Tani, Keiji
Joho Shori, 41(4), p.369 - 374, 2000/04
no abstracts in English
Tani, Keiji; Yokokawa, Mitsuo
Joho Shori, 41(3), p.249 - 254, 2000/03
no abstracts in English
