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Moriyama, Shinichi; Kajiwara, Ken*; Takahashi, Koji; Kasugai, Atsushi; Seki, Masami; Ikeda, Yoshitaka; Fujii, Tsuneyuki; JT-60 Team
Review of Scientific Instruments, 76(11), p.113504_1 - 113504_6, 2005/11
Times Cited Count：6 Percentile：33.46(Instruments & Instrumentation)A compact antenna has been designed and fabricated to enable millimeter wave beam scan in the toroidal and the poloidal directions of the JT-60U Tokamak, for electron cyclotron heating (ECH) and current drive (ECCD) experiments. It consists of fast movable flat mirror mounted on the Tokamak vacuum vessel, and rotary focusing mirror attached at the end of the waveguide supported from outside of the vacuum vessel. This separate support concept enables compact structure in the shallow port (0.68 m 
0.54 m 0.2m) sharing with a sub-port for an independent diagnostic system. The flat mirror is driven during a shot by a servo-motor with a 3 m long drive shaft to refuse influence of the high magnetic field to the motor. The focusing mirror is rotated by a simple mechanism with a push rod and an air cylinder. The antenna has been operated reliably for 3 years after small improvement in the rotary mechanism. It has been contributing ECH and ECCD experiments especially current profile control, in JT-60U.
Fujii, Tsuneyuki; Seki, Masami; Moriyama, Shinichi; Terakado, Masayuki; Shinozaki, Shinichi; Hiranai, Shinichi; Shimono, Mitsugu; Hasegawa, Koichi; Yokokura, Kenji; JT-60 Team
Journal of Physics; Conference Series, 25, p.45 - 50, 2005/00
The JT-60U electron cyclotron range of frequency (ECRF) is utilized to realize high performance plasma. Its output power is 4 MW at 110 GHz. By controlling the anode voltage of the gyrotron used in the JT-60U ECRF heating system, the gyrotoron output can be controlled. Then, the anode voltage controller was developed to modulate the injected power into plasmas. This low cost controller achieved the modulation frequency 12 - 500 Hz at 0.7 MW. This controller also extended the pulse width from 5s to 16 s at 0.5 MW. For these long pulses, temperature rise of the DC break made of Alumina ceramics is estimated. Its maximum temperature becomes 
140 deg. From the analysis of this temperature rise, DC break materials should be changed to low loss materials for the objective pulse width of 30 s. The stabilization of neoclassical tearing mode (NTM) was demonstrated by ECRF heating using the real-time system in which the ECRF beams are injected to the NTM location predicted from ECE measurement every 10 ms.
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.
JT-60 Team
JAERI-Review 2002-022, 149 Pages, 2002/11
JAERI-Review-2002-022.pdf:10.21MB
no abstracts in English
Seki, Masami; Moriyama, Shinichi; Kajiwara, Ken; Ikeda, Yoshitaka; Sakamoto, Keishi; Imai, Tsuyoshi; Fujii, Tsuneyuki
Journal of Plasma and Fusion Research SERIES, Vol.5, p.337 - 341, 2002/00
no abstracts in English
Takahashi, Koji; Imai, Tsuyoshi; Sakamoto, Keishi; Kobayashi, Noriyuki*; Mori, Seiji*; Mori, Kensuke*; Ito, Yasuyuki*; Shoyama, Hiroaki; Kasugai, Atsushi
Fusion Engineering and Design, 56-57, p.587 - 592, 2001/10
Times Cited Count：7 Percentile：48.68(Nuclear Science & Technology)no abstracts in English
JT-60 Team
JAERI-Review 2000-035, 164 Pages, 2001/02
JAERI-Review-2000-035.pdf:10.14MB
no abstracts in English
Takahashi, Koji; Kajiwara, Ken; Kasugai, Atsushi; Isayama, Akihiko; Ikeda, Yoshitaka; Ide, Shunsuke; Sakamoto, Keishi; Imai, Tsuyoshi; Fujii, Tsuneyuki
Fusion Engineering and Design, 53(1-4), p.511 - 516, 2001/01
Times Cited Count：18 Percentile：76.49(Nuclear Science & Technology)no abstracts in English
Isayama, Akihiko; Ikeda, Yoshitaka; Ide, Toshiyuki; Suzuki, Takahiro; Moriyama, Shinichi; Takahashi, Koji; Kajiwara, Ken; Oikawa, Toshihiro; Hamamatsu, Kiyotaka; Kamada, Yutaka; et al.
AIP Conference Proceedings 595, p.267 - 274, 2001/00
no abstracts in English
Fukuyama, Atsushi*; Takase, Yuichi*; Ide, Shunsuke; Ushigusa, Kenkichi
Purazuma, Kaku Yugo Gakkai-Shi, 76(2), p.127 - 137, 2000/02
no abstracts in English
Kajiwara, Ken; Kasugai, Atsushi; Takahashi, Koji; Ikeda, Yoshitaka; Imai, Tsuyoshi; Anno, Katsuto; Haga, Koichi*; Sakamoto, Keishi; Yokokura, Kenji; Shimono, Mitsugu; et al.
Journal of Plasma and Fusion Research SERIES, Vol.3, p.372 - 375, 2000/00
no abstracts in English
Fujii, Tsuneyuki; Imai, Tsuyoshi
Strong Microwaves in Plasmas 2000 Vol.2, p.615 - 628, 2000/00
no abstracts in English
Shinozaki, Shinichi; Shimono, Mitsugu; Terakado, Masayuki; Anno, Katsuto; Hiranai, Shinichi; Ikeda, Yoshitaka; Ikeda, Yukiharu; Imai, Tsuyoshi; Kasugai, Atsushi; Moriyama, Shinichi; et al.
Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering (SOFE '99), p.403 - 406, 1999/10
no abstracts in English
Tsuneoka, Masaki; Imai, Tsuyoshi; E.Bowles*; I.Benfatto*; *; *
Fusion Engineering and Design, 45(2), p.197 - 207, 1999/00
Times Cited Count：1 Percentile：13.12(Nuclear Science & Technology)no abstracts in English
Yamamoto, Takumi; Ushigusa, Kenkichi; Sakamoto, Keishi; Imai, Tsuyoshi; Miya, Naoyuki; ; Nagashima, Keisuke; *; Mori, Katsuharu*; Kikuchi, Mitsuru; et al.
JAERI-Research 97-006, 77 Pages, 1997/02
JAERI-Research-97-006.pdf:2.47MB
no abstracts in English
Tsuneoka, Masaki; Fujita, Hideo*; Sakamoto, Keishi; Kasugai, Atsushi; Imai, Tsuyoshi; Nagashima, Takashi; *; *; *; *; et al.
Fusion Engineering and Design, 36(4), p.461 - 469, 1997/00
Times Cited Count：23 Percentile：84.21(Nuclear Science & Technology)no abstracts in English
Kasugai, Atsushi; Takahashi, Koji; Sakamoto, Keishi; Yamamoto, Takumi; Tsuneoka, Masaki; Kariya, Tsuyoshi*; Imai, Tsuyoshi
Japanese Journal of Applied Physics, Part 1, 36(5A), p.2883 - 2887, 1997/00
Times Cited Count：4 Percentile：28(Physics, Applied)no abstracts in English
Ida, Katsumi*; Okano, Kunihiko*; Ogawa, Yuichi*; Kamada, Yutaka; Kimura, Haruyuki; Nishihara, Katsunobu*; Fujisawa, Akihide*; Yagi, Masatoshi*; Iio, Shunji*
Purazuma, Kaku Yugo Gakkai-Shi, 72(12), p.1417 - 1423, 1996/12
no abstracts in English
Nakajima, Kunihiko*; *; *
JAERI-M 87-154, 106 Pages, 1987/09
no abstracts in English
Kobayashi, Takayuki; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Hinata, Jun; Sato, Fumiaki; Yokokura, Kenji; Hoshino, Katsumichi; Isayama, Akihiko; et al.
no journal, ,
Design and developments of electron cyclotron range of frequency (ECRF) system are in progress. An oscillation of 1 MW for 1 s at 82 GHz has been demonstrated as the third frequency of the JT-60SA gyrotron, by which oscillations of 1 MW for 100 s at both 110 and 138 GHz were demonstrated. Moreover, experiments toward higher power (more than 1 MW) have been carried out. Oscillations of 1.5 MW for 5 s and 1.8 MW for 1 s at 110 GHz and 1.3 MW for 1 s at 138 GHz have been demonstrated, so far. Operation conditions will be optimized toward higher power and longer pulse length in future. In addition, the progress in the design and developments of ECRF power supply, launcher and transmission line are reported in the conference.
