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Katono, Kenichi*; Tamai, Hidesada*; Nagayoshi, Takuji*; Ito, Takashi*; Takase, Kazuyuki
Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 8 Pages, 2012/12
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
Proceedings of 7th International Conference on Multiphase Flow 2010 (ICMF 2010) (CD-ROM), 7 Pages, 2010/05
For the design the natural-circulation type BWR that utilizes the FSS concept, the development of a predictive model for the droplets entrained with the steam (carryover) from the free surface is indispensable. In this paper, the droplet quality was measured with a throttling calorimeter that could measure the droplet quality based on the isenthalpic process between wet and superheated steam through the throttle. The measurements were carried out under the conditions of a pressure of 1.5-2.5 MPa. The temperature of the superheated steam after passing through the throttle was confirmed to be strongly related to the quality of the wet steam. A modified model based on the measurements proved to be capable of predicting the droplet quality within the range of the database. Evaluating the droplet quality under BWR conditions validated the feasibility of the design of the natural-circulation type BWR that utilizes the FSS concept.
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
Nihon Konsoryu Gakkai Nenkai Koenkai 2009 Koen Rombunshu, P. 2, 2009/08
The characteristics of carryover from free-surface in a natural-circulation BWR are an important subject to be resolved for economic and safe design of the reactor. In this study, droplet quality of the carryover in a test section with 0.12 m in diameter was measured using throttling calorimeter with pressure ranging from 1.5-2.5 MPa. The measured droplet quality increases with decrease in distance from free-surface and with increase in vapor volumetric flux, and these trends are similar to those of previous data.
Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.
Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12
Times Cited Count：17 Percentile：72.86(Nuclear Science & Technology)no abstracts in English
Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.
Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12
To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.
Nagashima, Yoshihiko*; Hoshino, Katsumichi; Nagaoka, Kenichi*; Shinohara, Koji; Fujisawa, Akihide*; Uehara, Kazuya; Kusama, Yoshinori; Ida, Katsumi*; Yoshimura, Yasuo*; Okamura, Shoichi*; et al.
Plasma and Fusion Research (Internet), 1(9), p.041_1 - 041_15, 2006/09
Nonlinear processes between meso-scale structures and turbulent fluctuations in the edge region of the toroidal plasmas were studied using the bispectrum analysis. In the JFT-2M tokamak, divertor plasmas were investigated as well as the limiter plasmas, and the amplitude and phase of the bispectrum function of the potential fluctuation were found to be consistent with an analysis of the drift wave-zonal flow system. In the CHS machine, the edge plasmas during the H-mode were investigated. It was found that the edge potential begins to decrease before the decrease of the intensity of the deuterium line (by about 30ms), and the edge fluctuations are found to be composed of low frequency MHD fluctuations, drift wave like broad band electrostatic fluctuations and high frequency electromagnetic fluctuations. Nonlinear coupling between the MHD fluctuations and the electrostatic fluctuations or the electromagnetic fluctuations were found for the first time.
Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.
Nuclear Fusion, 46(3), p.S29 - S38, 2006/03
Times Cited Count：13 Percentile：41.76(Physics, Fluids & Plasmas)The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.
Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.
Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02
Times Cited Count：1 Percentile：9.98(Nuclear Science & Technology)no abstracts in English
Nagashima, Yoshihiko*; Ito, Kimitaka*; Ito, Sanae*; Fujisawa, Akihide*; Hoshino, Katsumichi; Nagaoka, Kenichi*; Ejiri, Akira*; Takase, Yuichi*; Yagi, Masatoshi*; Shinohara, Koji; et al.
Europhysics Conference Abstracts (CD-ROM), 30I, 4 Pages, 2006/00
The results of the analyses of nonlinear processes in the plasma in JFT-2M tokamak and CHS machine are reported. In both machines, the measurements of the fluctuations were done by electrostatic probes. The obtained bicoherence and biphase from the potential data in JFT-2M were found to be close to the values obtained from a theoretical model of the interaction of the zonal flow and the drift wave turbulence. Therefore the experimentally obtained nonlinear interaction is considered to be that interaction of the zonal flow and the drift wave turbulence. By the analysis of the CHS H-mode plasma, a marked nonlinear interaction was found between a characteristic MHD magnetic fluctuation and density turbulence. By analysing the cross bispectrum of the density fluctuation and the potential fluctuation, it was found that the fluctuating particle flux is affected by the MHD oscillation. As stated above, we progressed in the investigation of the nonlinear processes of the edge plasmas.
plasma operationTamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.
Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12
Times Cited Count：15 Percentile：45.53(Physics, Fluids & Plasmas)Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.
Sugita, Kenichiro*; Takase, Hiroyasu*
JNC TJ7440 2005-080, 105 Pages, 2004/03
JNC-TJ7440-2005-080.PDF:3.41MB
no abstracts in English
Shirai, Hiroshi; Hirayama, Toshio; Shimizu, Katsuhiro; Tani, Keiji; Azumi, Masafumi; Hirai, Kenichiro*; Konno, Satoshi*; Takase, Keizo*
JAERI-M 93-026, 97 Pages, 1993/02
no abstracts in English
Nagashima, Yoshihiko*; Hoshino, Katsumichi; Shinohara, Koji; Uehara, Kazuya; Kusama, Yoshinori; Nagaoka, Kenichi*; Fujisawa, Akihide*; Ida, Katsumi*; Yoshimura, Yasuo*; Okamura, Shoichi*; et al.
no journal, ,
We present an invited talk on the experimental study of the nonlinear interaction processes of the edge plasma turbulence studied in the JFT-2M tokamak machine of JAEA and in the CHS helical machine of the NIFS. We made a progress in understanding the nonlinear interaction of the drift wave turbulence and the zonal flow by measuring the potential fluctuations and density fluctuations by the measurement of the electrostatic probes. We found that the measured indices such as the bicoherence or the biphase are consistent with the results of a theoretical study of the drift-wave-zonal-flow system for the first time. We also made the convergence characteristic of these indices clear against the realization numbers for the first time. The study progresses the understanding of the plasma turbulence and structural formation in the plasma, and the results contributes much to the understanding of the transport process in the plasma.
Nagae, Daisuke; Takemuara, Makoto*; Ueno, Hideki*; Kameda, Daisuke*; Asahi, Koichiro*; Yoshimi, Akihiro*; Sugimoto, Takashi*; Nagatomo, Takashi*; Kobayashi, Yoshio*; Uchida, Makoto*; et al.
no journal, ,
An electric quadrupole moment (
moment) is sensitive to collective aspects of nuclear structure. In the -moment measurement for unstable nuclei, we employ the -detected nuclear-quadrupole resonance method. In this method, we need to supply 
resonance frequencies, where 
denotes the nuclear spin. We have developed a new RF-application system to induced all of the transitions. The application of the frequencies may be pursued in two different ways; the sequential RF pulse method and the mixed-wave RF pulse method. We confirmed the reversal of polarization for the both methods, from measurements of -ray asymmetry change for polarized 
B. Using this system, the moments of 
Al have been measured to be 
mb and 
mb by the sequential RF pulse method.
Takase, Misao; Haruyama, Mitsuo; Takamine, Jun; Yamaguchi, Satoshi; Akashi, Kenichi*
no journal, ,
no abstracts in English
Takamine, Jun; Haruyama, Mitsuo; Takase, Misao; Yamaguchi, Satoshi; Yamaguchi, Hiromi; Sakakibara, Tetsuro; Akashi, Kenichi*
no journal, ,
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
no journal, ,
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
no journal, ,
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
no journal, ,
no abstracts in English
Katono, Kenichi; Nagayoshi, Takuji; Tamai, Hidesada; Takase, Kazuyuki; Ito, Takashi
no journal, ,
no abstracts in English
