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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：59.60(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.
Seki, Masami; Moriyama, Shinichi; Shinozaki, Shinichi; Hasegawa, Koichi; Hiranai, Shinichi; Yokokura, Kenji; Shimono, Mitsugu; Terakado, Masayuki; Fujii, Tsuneyuki
Fusion Engineering and Design, 74(1-4), p.273 - 277, 2005/11
Times Cited Count：3 Percentile：23.33(Nuclear Science & Technology)no abstracts in English
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.
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
Seki, Masami; Ikeda, Yoshitaka; Maebara, Sunao; Moriyama, Shinichi; Naito, Osamu; Anno, Katsuto; Hiranai, Shinichi; Shimono, Mitsugu; Shinozaki, Shinichi; Terakado, Masayuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.452 - 466, 2002/09
Times Cited Count：14 Percentile：64.35(Nuclear Science & Technology)no abstracts in English
Ikeda, Yoshitaka; Kasugai, Atsushi; Moriyama, Shinichi; Kajiwara, Ken*; Seki, Masami; Tsuneoka, Masaki*; Takahashi, Koji; Anno, Katsuto; Hamamatsu, Kiyotaka; Hiranai, Shinichi; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.435 - 451, 2002/09
Times Cited Count：26 Percentile：81.47(Nuclear Science & Technology)no abstracts in English
Shinozaki, Shinichi; Moriyama, Shinichi; Shimono, Mitsugu; Hiranai, Shinichi
NIFS-MEMO-36, p.87 - 90, 2002/06
no abstracts in English
Ikeda, Yoshitaka; Kasugai, Atsushi; Takahashi, Koji; Kajiwara, Ken; Isayama, Akihiko; Ide, Shunsuke; Terakado, Masayuki; Shinozaki, Shinichi; Yokokura, Kenji; Anno, Katsuto; et al.
Fusion Engineering and Design, 53(1-4), p.351 - 363, 2001/01
Times Cited Count：40 Percentile：91.52(Nuclear Science & Technology)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
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
Ikeda, Yoshitaka; Fujita, Takaaki; Hamamatsu, Kiyotaka; Ide, Shunsuke; Imai, Tsuyoshi; Isayama, Akihiko; Iwase, Makoto; Kasugai, Atsushi; Kondoh, Takashi; Kusama, Yoshinori; et al.
AIP Conference Proceedings 485, p.279 - 287, 1999/09
no abstracts in English
Kawamura, Kazuhiro; Tanigawa, Katsuya; Shinozaki, Mitsugu*; Kobayashi, Hiroaki
PNC TN8410 98-032, 120 Pages, 1998/02
None
; ; Kawamura, Kazuhiro; Kobayashi, Hiroaki; ;
PNC TN8100 97-003, 179 Pages, 1997/10
no abstracts in English
Kawamura, Kazuhiro; ; ; Ouchi, Jin;
PNC TN8100 96-003, 173 Pages, 1996/03
no abstracts in English
Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; et al.
no journal, ,
The electron cyclotron range of frequency (ECRF) system (3 MW 
5s at 110 GHz with 4 gyrotrons) of JT-60U will be upgrade to the system having 9 gyrotrons (7 MW 100s) for JT-60SA (super advanced). As heat removal from the mirrors is essential for a long pulse antenna, a new concept with a mirror driven in the linear motion which eliminates the flexible tube for coolant supply is under development. The design study featuring beam profile calculation showed feasibility of the antenna in the 0.48 m 0.48 m port. The low power rf test with simple mockup antenna has just been begun. Aging of the gyrotron with improved mode converter was started in the end of 2008, aiming at 1 MW, 100s oscillation. Because the current capacity of the present high voltage power supply is not enough to realize 100s oscillation, LHRF power supply having twice larger current capacity is connected to the gyrotron in March 2009. The gyrotron aging will be started soon again.
Sawahata, Masayuki; Shimono, Mitsugu; Shinozaki, Shinichi; Terakado, Masayuki; Igarashi, Koichi; Takahashi, Masami; Seki, Masami
no journal, ,
no abstracts in English
Fujii, Tsuneyuki; Seki, Masami; Moriyama, Shinichi; Terakado, Masayuki; Suzuki, Sadaaki; Shinozaki, Shinichi; Sawahata, Masayuki; Hiranai, Shinichi; Igarashi, Koichi; Shimono, Mitsugu
no journal, ,
no abstracts in English
Kobayashi, Takayuki; Moriyama, Shinichi; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Igarashi, Koichi; et al.
no journal, ,
In JT-60SA, 7 MW of electron cyclotron heating and current drive will be performed with four units of 110 GHz and five units of 140 GHz electron cyclotron range of frequency (ECRF) systems. Transmission lines will be connected into four upper outer ports where quasi-optical antennas will be installed. Two types of antenna systems are being considered. One is a conventional type rotation antenna and the other is a new concept antenna which can control incident angle by a linearly driven mirror. Those antennas are now being evaluated from the view points of cooling structure, the range of incident angle and beam width. In addition, 1.5 MW for 1 s oscillation was carried out by one gyrotron of JT-60U ECRF system. Moreover, the present 110 GHz gyrotron will be improved which aims at the development of JT-60SA gyrotron. In this presentation, current status of design study for JT-60SA ECRF system and the latest results of the JT-60U ECRF system will be presented.
