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Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Terakado, Masayuki; Sawahata, Masayuki; Suzuki, Sadaaki; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Hiranai, Shinichi; et al.
Nuclear Fusion, 49(8), p.085001_1 - 085001_7, 2009/07
Times Cited Count：21 Percentile：61.72(Physics, Fluids & Plasmas)In the gyrotron development in JT-60U ECRF system, output power of 1.5 MW for 1 s has been achieved at 110 GHz. It is the world highest power oscillation 
1 s. In addition to the carefully designed cavity and collector in view of thermal stress, an RF shield for the adjustment bellows, and a low-dielectric-loss DC break enabled this achievement. Power modulation technique by anode voltage control was improved to obtain high modulation frequency and 5 kHz has been achieved for NTM stabilizing experiments. Long pulse demonstration of 0.4 MW, 30 s injection to the plasma has been achieved with real time control of anode/cathode-heater. It has been confirmed that the temperature of cooled components were saturated and no evidence of damage were found. An innovative antenna having wide range of beam steering capability with linearly-moving-mirror concept has been designed for long pulse. Beam profile and mechanical strength analyses shows the feasibility of the antenna.
Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Terakado, Masayuki; Sawahata, Masayuki; Suzuki, Sadaaki; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Hiranai, Shinichi; et al.
Proceedings of 22nd IAEA Fusion Energy Conference (FEC 2008) (CD-ROM), 8 Pages, 2008/10
In the gyrotron development in JT-60U ECRF system, output power of 1.5 MW for 1 s has been achieved at 110 GHz. It is the world highest power oscillation 1 s. In addition to the carefully designed cavity and collector in view of thermal stress, an RF shield for the adjustment bellows, and a low-dielectric-loss DC break enabled this achievement. Power modulation technique by anode voltage control was improved to obtain high modulation frequency and 5 kHz has been achieved for NTM stabilizing experiments. Long pulse demonstration of 0.4 MW, 30 s injection to the plasma has been achieved with real time control of anode/cathode-heater. It has been confirmed that the temperature of cooled components were saturated and no evidence of damage were found. An innovative antenna having wide range of beam steering capability with linearly-moving-mirror concept has been designed for long pulse. Beam profile and mechanical strength analyses shows the feasibility of the antenna.
Terakado, Masayuki; Shimono, Mitsugu; Sawahata, Masayuki; Shinozaki, Shinichi; Igarashi, Koichi; Sato, Fumiaki; Wada, Kenji; Seki, Masami; Moriyama, Shinichi
JAEA-Technology 2007-053, 28 Pages, 2007/09
JAEA-Technology-2007-053.pdf:4.3MB
The electron cyclotron heating (ECH) system at 110 GHz are injected to JT-60U plasmas with pulse modulation at dozens to hundreds of Hz in order to measure heat conductivity of the plasma to investigate plasma confinement. The JT-60U ECH system has a unique feature to realize the pulse modulation by controlling the anode voltage of the triode gyrotron without chopping the main acceleration voltage. The typical depth of the modulation is 80 % at the modulation frequency range of 12.2 Hz to 500 Hz. However in the JT-60SA, higher modulation frequency of some kHz will be required to stabilize neoclassical tearing mode (NTM). The modulation techniques have been investigated and the modulation frequency of 3.5 kHz with the modulation depth of 84 % has been achieved. The modulation frequency up to 3 kHz is available in the pulse widths of the practical operation. As a next step, replacement of the parts in the anode voltage divider circuit is planned to achieve higher modulation frequency.
Shimono, Mitsugu; Seki, Masami; Terakado, Masayuki; Igarashi, Koichi*; Ishii, Kazuhiro*; Takahashi, Masami*; Shinozaki, Shinichi; Hiranai, Shinichi; Sato, Fumiaki*; Anno, Katsuto
JAERI-Tech 2003-075, 29 Pages, 2003/09
JAERI-Tech-2003-075.pdf:4.62MB
no abstracts in English
Shibata, Keiichi; *; Asami, Tetsuo*; Mizumoto, Motoharu; *; *; *
Journal of Nuclear Science and Technology, 34(5), p.503 - 509, 1997/05
Times Cited Count：3 Percentile：30.37(Nuclear Science & Technology)no abstracts in English
Nakagawa, Tsuneo; Shibata, Keiichi; Chiba, Satoshi; Fukahori, Tokio; Nakajima, Yutaka; ; Kawano, Toshihiko*; Kanda, Yukinori*; Osawa, Takaaki*; Matsunobu, Hiroyuki*; et al.
Journal of Nuclear Science and Technology, 32(12), p.1259 - 1271, 1995/12
Times Cited Count：497 Percentile：99.95(Nuclear Science & Technology)no abstracts in English
Shibata, Keiichi; *; Asami, Tetsuo*
INDC(NDS)-334, 0, p.127 - 136, 1995/05
no abstracts in English
*; Fukahori, Tokio
JAERI 1321, 80 Pages, 1991/03
no abstracts in English
Igarashi, Hiroshi; Saito, Shinichi*
PNC TN8600 90-011, 188 Pages, 1990/09
no abstracts in English
Igarashi, Hiroshi; Saito, Shinichi*; Takahashi, Takeshi; Yoshioka, Masahiro
PNC TN8600 90-010, 72 Pages, 1990/09
no abstracts in English
Shibata, Keiichi; Nakagawa, Tsuneo; Asami, Tetsuo*; Fukahori, Tokio; ; Chiba, Satoshi; Mizumoto, Motoharu; ; ; Nakajima, Yutaka; et al.
JAERI 1319, 516 Pages, 1990/06
no abstracts in English
Asami, Tetsuo*; Iijima, Shungo*; ; Ihara, Hitoshi; Kawai, Masayoshi*; ; Komuro, Yuichi; Shibata, Keiichi; Takano, Hideki; *; et al.
Nihon Genshiryoku Gakkai-Shi, 31(11), p.1190 - 1217, 1989/11
no abstracts in English
Journal of Nuclear Science and Technology, 26(1), p.5 - 10, 1989/01
no abstracts in English
JAERI-M 88-067, 32 Pages, 1988/03
no abstracts in English
; Asami, Tetsuo
JAERI-M 86-029, 210 Pages, 1986/03
no abstracts in English
Shirakata, Keisho; Koizumi, Masumichi*; *; *; *; *
Genshiryoku Kogyo, 31(8), p.43 - 65, 1985/08
; *; ; ; *
JAERI-M 84-182, 107 Pages, 1984/10
no abstracts in English
Igarashi, Shinichi; Asami, Tetsuo; Kikuchi, Yasuyuki; Nakagawa, Tsuneo; Narita, Tsutomu; Shibata, Keiichi
Nihon Genshiryoku Gakkai-Shi, 26(3), p.191 - 198, 1984/00
Times Cited Count：3 Percentile：38.16(Nuclear Science & Technology)no abstracts in English
JAERI-M 83-145, 45 Pages, 1983/08
no abstracts in English
Shibata, Keiichi; Narita, Tsutomu;
JAERI-M 83-006, 45 Pages, 1983/02
no abstracts in English
