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Oshima, Katsumi; Oda, Yasuhisa; Takahashi, Koji; Terakado, Masayuki; Ikeda, Ryosuke; Hayashi, Kazuo*; Moriyama, Shinichi; Kajiwara, Ken; Sakamoto, Keishi
JAEA-Technology 2015-061, 65 Pages, 2016/03
JAEA-Technology-2015-061.pdf:24.28MB
In JAEA, an ITER relevant control system for ITER gyrotron was developed according to Plant Control Design Handbook. This control system was developed based on ITER CODAC Core System and implemented state machine control of gyrotron operation system, sequential timing control of gyrotron oscillation startup, and data acquisition. The operation of ITER 170 GHz gyrotron was demonstrated with ITER relevant power supply configuration. This system is utilized for gyrotron operation test for ITER procurement. This report describes the architecture of gyrotron operation system, its basic and detailed design, and recent operation results.
Kobayashi, Takayuki; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Ikeda, Ryosuke; Oda, Yasuhisa; Wada, Kenji; Hinata, Jun; Yokokura, Kenji; Hoshino, Katsumichi; et al.
Proceedings of 40th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2015) (USB Flash Drive), 3 Pages, 2015/08
A gyrotron for electron cyclotron heating and current drive (ECH/CD) has been developed for JT-60SA (Super-Advanced). In high-power, long-pulse operations, oscillations of 1 MW/100 s have been demonstrated at both 110 GHz and 138 GHz, for the first time. These results fully satisfied the requirements for JT-60SA. Moreover, it was experimentally shown that the higher power operation at each frequency is expected to be acceptable for this gyrotron from the viewpoint of heat load at the cavity resonator, collector, and stray radiation absorbers. An oscillation at 82 GHz, which is an additional frequency, has been demonstrated up to 2 s at the output power of 0.4 MW, so far. High power experiments toward higher power of 1.5 MW (110/138 GHz) and 1 MW (82 GHz) are ongoing.
Kobayashi, Takayuki; Moriyama, Shinichi; Yokokura, Kenji; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Hoshino, Katsumichi; et al.
Nuclear Fusion, 55(6), p.063008_1 - 063008_8, 2015/06
Times Cited Count：25 Percentile：77.57(Physics, Fluids & Plasmas)A gyrotron enabling high-power, long-pulse oscillations at both 110 GHz and 138 GHz has been developed for electron cyclotron heating (ECH) and current drive (CD) in JT-60SA. Oscillations of 1 MW for 100 s have been demonstrated at both frequencies, for the first time as a gyrotron operating at two frequencies. The optimization of the anode voltage, or the electron pitch factor, using a triode gun was a key to obtain high power and high efficiency at two frequencies. It was also confirmed that the internal losses in the gyrotron were sufficiently low for expected long pulse operation at the higher power level of 
1.5 MW. Another important result is that an oscillation at 82 GHz, which enables to use fundamental harmonic waves in JT-60SA while the other two frequencies are used as second harmonics waves, was demonstrated up to 0.4 MW for 2 s. These results of the gyrotron development significantly contribute to enhancing operation regime of the ECH/CD system in JT-60SA.
Oda, Yasuhisa; Oshima, Katsumi; Nakamoto, Takashi*; Hashimoto, Yasunori*; Yamamoto, Tsuyoshi; Hayashi, Kazuo*; Ikeda, Yukiharu; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 90(7), p.365 - 373, 2014/07
no abstracts in English
n eigenmode dampingMatsunaga, Go; Toi, Kazuo*; Ikeda, Ryosuke*; Takeuchi, Masaki*; Takechi, Manabu; Nakajima, Noriyoshi*; Fukuyama, Atsushi*
no journal, ,
no abstracts in English
Moriyama, Shinichi; Kobayashi, Takayuki; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Yokokura, Kenji; Hoshino, Katsumichi; et al.
no journal, ,
Long pulse operation of the dual frequency gyrotron was started for JT-60SA ECH system. Pulse length of 2 s at 0.4 MW output, and 1 s at 0.7 MW were obtained at both 110 GHz and 138 GHz, so far. Typical oscillation efficiency is about 30%. Diffraction loss was acceptable for long pulse 1 MW output. The first high power test of the "power and beam profile monitor" featuring a fast movable Si
N
disk in the waveguide slit was successfully demonstrated.
Kobayashi, Takayuki; Isayama, Akihiko; Hiranai, Shinichi; Sawahata, Masayuki; Terakado, Masayuki; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Yokokura, Kenji; Hoshino, Katsumichi; et al.
no journal, ,
An original design of the toroidal injection angle range of electron cyclotron waves in JT-60SA was -15 degree to +15 degree for effective use of 110 GHz wave. However, the modification of the toroidal angle range has been discussed since the frequency of 138 GHz is considered to be a second frequency by the use of a dual frequency gyrotron. We report newly calculated available steering range of the launcher on both poloidal and toroidal angles with and without tilting angle of the second mirror, which is considered to obtain large toroidal injection angle. Moreover calculated beam divergences for various curvature radiuses of the first and second mirrors are shown. The decision of the target injection angle range for JT-60SA initial plasma will be made by the JT-60SA physics team by taking into account the above calculation results.
Oda, Yasuhisa; Oshima, Katsumi; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; Hayashi, Kazuo*; Sakamoto, Keishi; Purohito, D.*; Henderson, M.*
no journal, ,
Oda, Yasuhisa; Ikeda, Ryosuke; Kajiwara, Ken; Oshima, Katsumi; Hayashi, Kazuo*; Takahashi, Koji; Sakamoto, Keishi; Purohito, D.*; Henderson, M.*
no journal, ,
no abstracts in English
Kobayashi, Takayuki; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Yokokura, Kenji; Hoshino, Katsumichi; Takahashi, Koji; et al.
no journal, ,
Developments of a dual frequency (110 GHz and 138 GHz) electron cyclotron heating and current drive system for JT-60SA are required. In a long pulse operation of a dual-frequency gyrotron, oscillations of 1 MW for 10 s at both frequencies were obtained, so far. Out gas in the gyrotron has been decreased shot by shot, and conditioning of the gyrotron is in progress. Oscillation efficiencies of higher than 30% were obtained for both frequencies. Measured internal diffraction loss was almost the same level of the previously developed 110 GHz long pulse gyrotron. From the above results, it is expected that further pulse length expansion is possible by continuing conditioning operations. Moreover, optical characteristics of an antenna, which is used to inject high-power millimeter waves into tokamak, was confirmed for dual frequency operation. It was found that the beam width for the 138 GHz wave is narrower than that for the 110 GHz wave.
Ikeda, Ryosuke; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Aoki, Takashi; Oshima, Katsumi; Tsubota, Naoaki; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,
no abstracts in English
Moriyama, Shinichi; Kobayashi, Takayuki; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Yokokura, Kenji; Hoshino, Katsumichi; et al.
no journal, ,
Long pulse operation of the dual frequency gyrotron was started for JT-60SA ECH system. Pulse lengths of 10 s with output power of 1MW were obtained at both 110 GHz and 138 GHz, so far. Typical oscillation efficiency is approximately 30%. Diffraction loss was acceptable for long pulse 1 MW output. The first high power test of the "power / beam profile monitor" featuring a fast movable Si3N disk in the waveguide slit was successfully demonstrated.
Ikeda, Ryosuke; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,
TE
mode gyrotron has advantages for multi-frequency oscillation. Triple frequency of 170 GHz, 137 GHz and 104 GHz pass through a diamond disk window without a reflection lose and are radiated toward the same direction without moving a final mirror in the gyroton. In short pulse experiments (
5s), the output power, the oscillation efficiency and the electric efficiency for 170 GHz, 137 GHz and 104 GHz oscillation achieved 1.2 MW/27%/43%, 810 kW/25%/40% and 720 kW/25%/38%. In long pulse operation, pulse length reached 100s with 870 kW output power for 170 GHz oscillation. HE11 mode purity measured at the MOU exit was 94.5%, 93% and 92% for 170 GHz, 137 GHz and 104 GHz oscillation. By building precisely a transmission line, the purity of 91%, 88% and 95%, respectively is obtained at the exit of the long transmission line (35 m).
Ikeda, Ryosuke; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,
TE mode gyrotron has advantages for multi-frequency oscillation. Oscillations of 170 GHz, 137 GHz and 104 GHz at TE, TE
and TE
modes, respectively are excited by varying the magnetic field strength. In high power experiments, the output power, the oscillation efficiency and the electric efficiency for 170 GHz, 137 GHz and 104 GHz oscillation achieved 1.2 MW / 27% / 43%, 810 kW / 25% / 40% and 720 kW / 25% / 38%. In long pulse operation, 900 kW / 100 s, 800 kW / 224 s and 650 kW / 433 s for 170 GHz oscillation are obtained. HE
mode purity of 91%, 88% and 95% for 170 GHz, 137 GHz and 104 GHz oscillation is obtained at the exit of a 40 m transmission line.
Oda, Yasuhisa; Oshima, Katsumi; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji
no journal, ,
no abstracts in English
Oda, Yasuhisa; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; Sakamoto, Keishi
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Ikeda, Ryosuke; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,
no abstracts in English
Takahashi, Koji; Abe, Ganji; Isozaki, Masami; Ikeda, Ryosuke; Oda, Yasuhisa; Kajiwara, Ken; Sakamoto, Keishi; Kobayashi, Noriyuki*; Iida, Hiromasa*; Komatsuzaki, Manabu*; et al.
no journal, ,
It was analytically obtained that electron cyclotron current drive efficency at 
=0.40.6 can be doubled modifying the steering function of millimeter wave launching from the equatorial port from toroidally to poloidally. The design modification of the ITER equatorial launcher enhancing ECCD function is implemented. The millimeter wave design satisfying transmission efficiency more than 99% with the required ploidal beam steering capability is successfully obtained and reflected to the launcher structural design. The millimeter wave design optimization, BSM design modification to allow the required polidal beam steering capability and so on are reported in detail at the conference.
Ikeda, Ryosuke; Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi
no journal, ,
Long pulse gyrotrons for ITER are under development. At present, output power of 1.2 MW for 2 s pulse operation and long pulse operation of 1000 s at 0.5 MW were achieved in experiments of TE31,11 mode gyrotron. Moreover, a transmission efficiency of 91% was obtained in 40 m transmission experiment. Recently, development of TE31,9 mode gyrotron was started. 1 MW with oscillation efficiency of 33% was realized in 1 ms operation without depressed collector voltage. And, 0.61 MW with total electric efficiency 51 % was achieved in 10 s operation with depressed collector voltage.
Oshima, Katsumi; Oda, Yasuhisa; Hashimoto, Yasunori*; Hayashi, Kazuo*; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; Sakamoto, Keishi
no journal, ,
In the ITER gyrotron development activity, the local control system for ITER gyrotron has been carried out using the ITER CODAC Core system. This control system is composed of Fast controller and Slow controller. The former has a role to control the gyrotron oscillation, timing control, data acquisition, etc. The later has a role to manage the operation phase shift, machine protection and alarm management, etc. Using this prototype system, we succeeded the gyrotron oscillation and 5 kHz power modulation.
