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Kitamura, Akihisa*; Okazaki, Sota*; Kondo, Mitsuru*; Watanabe, Takahiro; Nakanishi, Toshimichi*; Hori, Rie*; Ikeda, Masayuki*; Ichimura, Koji; Nakagawa, Yuki; Mori, Hideki*
Shizuoka Daigaku Chikyu Kagaku Kenkyu Hokoku, (49), p.73 - 86, 2022/07
On July 3 2021, a debris flow caused by a landslide from a landfill occurred along the Aizome River in the Izusan area of Atami City, Shizuoka. In this study, debris flow deposits and soil samples were characterized in terms of their sedimentology and geochemically analyzed.
Wada, Ken*; Hyodo, Toshio*; Yagishita, Akira*; Ikeda, Mitsuo*; Osawa, Satoshi*; Shidara, Tetsuo*; Michishio, Koji*; Tachibana, Takayuki*; Nagashima, Yasuyuki*; Fukaya, Yuki; et al.
European Physical Journal D, 66(2), p.37 - 40, 2012/02
Times Cited Count：38 Percentile：85.19(Optics)no abstracts in English
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：72.65(Nuclear Science & Technology)no abstracts in English
Ikeda, Yoshitaka; Akino, Noboru; Ebisawa, Noboru; Hanada, Masaya; Inoue, Takashi; Honda, Atsushi; Kamada, Masaki; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; et al.
Fusion Engineering and Design, 82(5-14), p.791 - 797, 2007/10
Times Cited Count：22 Percentile：80.6(Nuclear Science & Technology)Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject 34 MW for 100 s. The upgraded NBI system consists of twelve positive ion based NBI (P-NBI) units and one negative ion based NBI (N-NBI) unit. The injection power of the P-NBI units are 2 MW each at 85 keV, and the N-NBI unit will be 10 MW at 500 keV, respectively. On JT-60U, the long pulse operation of 30 s at 2 MW (85 keV) and 20 s at 3.2 MW (320 keV) have been achieved on P-NBI and N-NBI units, respectively. Since the temperature increase of the cooling water in both ion sources is saturated within 20 s, further pulse extension up to 100 s is expected to mainly modify the power supply systems in addition to modification of the N-NBI ion source for high acceleration voltage. The detailed technical design of the NBI system for JT-60SA is presented.
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.
Kikuchi, Mitsuru; Matsuda, Shinzaburo; Yoshida, Naoaki*; Takase, Yuichi*; Miura, Yukitoshi; Fujita, Takaaki; Matsukawa, Makoto; Tamai, Hiroshi; Sakurai, Shinji; Ikeda, Yoshitaka; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 82(8), p.455 - 469, 2006/08
no abstracts in English
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：41.68(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：9.94(Nuclear Science & Technology)no abstracts in English
Kajiwara, Ken; Ikeda, Yoshitaka; Sakamoto, Keishi; Kasugai, Atsushi; Seki, Masami; Moriyama, Shinichi; Takahashi, Koji; Imai, Tsuyoshi; Mitsunaka, Yoshika*; Fujii, Tsuneyuki
Fusion Engineering and Design, 65(4), p.493 - 499, 2003/07
Times Cited Count：11 Percentile：33.33(Nuclear Science & Technology)no abstracts in English
Sakamoto, Keishi; Kasugai, Atsushi; Ikeda, Yoshitaka; Hayashi, Kenichi*; Takahashi, Koji; Moriyama, Shinichi; Seki, Masami; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Fujii, Tsuneyuki; et al.
Nuclear Fusion, 43(7), p.729 - 737, 2003/07
Development of high power gyrotrons at 170GHz and 110GHz have beed carried out. At 170GHz gyrotron that is required for ITER, high power outputs of 0.9MW/9sec, 0.75MW/17sec, 0.5MW/30sec, 0.3MW/60sec have been obtained. At 110GHz gyrotron for JT-60U, 1.2MW/4sec was obtained. The 110GHz gyrotron is under operation at 4MW electron cyclotron heating and current drive system on JT-60U.
Terakado, Masayuki; Seki, Masami; Shimono, Mitsugu; Igarashi, Koichi*; Mitsunaka, Yoshika*; Isayama, Akihiko; Anno, Katsuto; Ikeda, Yoshitaka
JAERI-Tech 2003-053, 25 Pages, 2003/06
JAERI-Tech-2003-053.pdf:3.23MB
The Electron Cyclotron Range of Frequencies (ECRF) system having four 110 GHz-gyrotrons has been successfully operated on JT-60U to locally heat a plasma (ECH) and drive a plasma current (ECCD) for high plasma performance owing to suppressing MHD activities. For investigation of plasma confinement the ECRF power is intermittently injected into plasmas to evaluate thermal conductivity. We have successfully performed power modulation by changing the anode voltage. The power modulation ratio of 80 % is attained changing the anode voltage by only about 10%. Modulation frequency is from 12 Hz to 500 Hz. The mode converter is heated when oscillation efficiency of the main mode decreases in changing the anode voltage. This seems to be due to the parasitic oscillation at the entrance of the converter. The gyrotron will be able to be protected by monitoring the temperature rise in the converter.
Kasugai, Atsushi; Sakamoto, Keishi; Hayashi, Kenichi*; Takahashi, Koji; Shoyama, Hiroaki*; Kajiwara, Ken*; Ikeda, Yoshitaka; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Fujii, Tsuneyuki; et al.
JAERI-Research 2002-027, 57 Pages, 2002/11
JAERI-Research-2002-027.pdf:3.6MB
no abstracts in English
Sakamoto, Keishi; Kasugai, Atsushi; Ikeda, Yoshitaka; Hayashi, Kenichi*; Takahashi, Koji; Kajiwara, Ken; Moriyama, Shinichi; Seki, Masami; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; et al.
Proceedings of 19th IAEA Fusion Energy Conference (FEC 2002) (CD-ROM), 5 Pages, 2002/10
The development of a key EC component, 1 MW gyrotron, and integration of the EC technologies on JT-60U EC system have been carried out. In the development of 1 MW gyrotron, the output of 1.3 MW was achieved. In pulse extension experiment, the outputs of 0.9 MW for 9.2 second and 0.5 MW for 30 sec. at 170 GHz, and 1.2 MW for 4.1 sec. at 110 GHz. In the JT-60U EC system, the maximum injection performances were 3 MW for 2sec, and contributed to produce high electron temperature plasma of 26 keV.
Ushigusa, Kenkichi; Ide, Shunsuke; Oikawa, Toshihiro; Suzuki, Takahiro; Kamada, Yutaka; Fujita, Takaaki; Ikeda, Yoshitaka; Naito, Osamu; Matsuoka, Mamoru*; Kondoh, Takashi; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.255 - 277, 2002/09
Times Cited Count：10 Percentile：15.15(Nuclear Science & Technology)Studies on non-inductive current drive and development of an integrated steady-state high performance operation in JT-60 are reviewed. Experiments on lower hybrid current drive in JT-60 haven shown a large non-inductive current up to 3.5MA, high current drive efficiency of 3.6x1019m-2A/W. Basic studies on LH waves in JT-60 have contributed to understand current drive physics. Significant progress in neutral beam current drive has been made in JT-60 by testing the performance of negative ion based NBI (N-NBI). The CD efficiency of ~1.5x1019m-2A /W, and N-NB driven current of ~1MA have been demonstrated in N-NBCD. Strongly localized driven current by electron cyclotron current drive was identified with a fundamental O-mode scheme. Efficiency of 0.5x1019m-2A/W and EC driven current of 0.2MA were achieved and suppression of neo-classical tearing mode was demonstrated. Based on these developments, two integrated steady-state operation scenarios were developed in JT-60, which are reversed magnetic shear (R/S) plasmas and high bp ELMy H-mode. In these operation regimes, discharges have been sustained near the steady-state current profile under full non-inductive current drive. High performance plasmas with a high nDotETio and at high normalized density were also produced under fully non-inductive condition in high bp ELMy H-mode and R/S mode.
Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.185 - 254, 2002/09
Times Cited Count：34 Percentile：48.48(Nuclear Science & Technology)With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.
mode with depressed collectorShoyama, Hiroaki; Sakamoto, Keishi; Hayashi, Kenichi*; Kasugai, Atsushi; Tsuneoka, Masaki; Takahashi, Koji; Ikeda, Yukiharu; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Imai, Tsuyoshi
Japanese Journal of Applied Physics, Part 2, 40(8B), p.L906 - L908, 2001/08
Times Cited Count：28 Percentile：71.88(Physics, Applied)no abstracts in English
Kasugai, Atsushi; Sakamoto, Keishi; Takahashi, Koji; Kajiwara, Ken; Shoyama, Hiroaki; Ikeda, Yukiharu; Tsuneoka, Masaki; Ikeda, Yoshitaka; Fujii, Tsuneyuki; Kariya, Tsuyoshi*; et al.
Fusion Engineering and Design, 53(1-4), p.399 - 406, 2001/01
Times Cited Count：17 Percentile：74.75(Nuclear Science & Technology)no abstracts in English
Shoyama, Hiroaki; Sakamoto, Keishi; Hayashi, Kenichi*; Kasugai, Atsushi; Takahashi, Koji; Tsuneoka, Masaki; Ikeda, Yukiharu; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Imai, Tsuyoshi
Shingaku Giho, 100(506), p.39 - 44, 2000/12
no abstracts in English
Imai, Tsuyoshi; Sakamoto, Keishi; Kasugai, Atsushi; Tsuneoka, Masaki; Takahashi, Koji; Shoyama, Hiroaki; Ikeda, Yukiharu; Ikeda, Yoshitaka; Kajiwara, Ken; Fujii, Tsuneyuki; et al.
Heisei-12-Nendo Denki Gakkai Genshiryoku Kenkyu Shiryo (NE-00-4), p.19 - 24, 2000/09
no abstracts in English
Sakamoto, Keishi; Kasugai, Atsushi; Shoyama, Hiroaki; Hayashi, Kenichi*; Takahashi, Koji; Tsuneoka, Masaki; Ikeda, Yukiharu; Ikeda, Yoshitaka; Kajiwara, Ken; Moriyama, Shinichi; et al.
25th International Conference on Infrared and Millimeter Waves Conference Digest, p.11 - 12, 2000/00
no abstracts in English
