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Saigusa, Mikio*; Atsumi, Kohei*; Yamaguchi, Tomoki*; Nagashima, Koji*; Fukunari, Masafumi*; Oda, Yasuhisa; Sakamoto, Keishi
no journal, ,
Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; et al.
no journal, ,
Development of an antenna featuring linear motion (LM) concept for electron cyclotron range of frequency (ECRF) heating and current drive in JT-60SA is in progress. It will handle the injection power of 1MW for 100s. Combination of a linearly movable first mirror and a fixed curved second mirror realizes control of the injection beam angle. A support structure of the shaft using a metallic sliding bearing with solid lubricant was designed and tested. It showed smooth movement in vacuum. Heating and current drive characteristics with the LM antenna for typical experimental scenarios of JT-60SA have been investigated by calculation. As a result, it was confirmed by ECCD calculation that the range of toroidal injection angle, from -15 deg to +15 deg is appropriate at 110 GHz. On the contrary, at 138GHz for experiment scenario at 2.3T of full toroidal field of JT-60SA, the angle in the positive direction of IP, may be larger, e.g., +20 deg, for higher ECCD efficiency.
Kobayashi, Takayuki; Isayama, Akihiko; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Yokokura, Kenji; Hoshino, Katsumichi; et al.
no journal, ,
Gyrotron developments for JT-60SA electron cyclotron range of frequency heating system have been carried out. A dual frequency gyrotron was developed for extending operation region of the system. A dual frequency gyrotron for 110 GHz and 138 GHz was designed and fabricated. Oscillations of 1 MW and 0.5 MW were obtained at 110 GHz and 138 GHz, respectively, for 0.1 s, so far. The oscillation efficiencies were consistent with the design. Experiments of a gyrotron equipping an improved mode convertor for reducing temperature increase of internal components due to stray radiation were also carried out toward long pulse operations of 100 s required in JT-60SA. Since an increase of waveguide temperature had been limited the pulse length, waveguide components with wider diameter, which is suitable for long pulse operation, were installed. An oscillation of 70 s at 1 MW, which is twice longer than the previous record, was obtained. A high power oscillation of 1.4 MW for 9 s was also obtained.
Oda, Yasuhisa; Takahashi, Koji; Fukunari, Masafumi*; Kajiwara, Ken; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,