Development of ITER CODAC compatible gyrotron local control system and its operation

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.

Gyrotron development for high-power, long-pulse electron cyclotron heating and current drive at two frequencies in JT-60SA and its extension toward operation at three frequencies

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

https://doi.org/10.1088/0029-5515/55/6/063008

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.

Bipartite magnetic parent phases in the iron oxypnictide superconductor

Hiraishi, Masatoshi*; Iimura, Soshi*; Kojima, Kenji*; Yamaura, Junichi*; Hiraka, Haruhiro*; Ikeda, Kazutaka*; Miao, P.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Miyazaki, Masanori*; et al.

Nature Physics, 10(4), p.300 - 303, 2014/04

https://doi.org/10.1038/nphys2906

Progress in dual frequency system developments for electron cyclotron heating and current drive in JT-60SA

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.

Development of 170 GHz / 1 MW Gyrotron system for ITER in JAEA

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).

Progress on development of mega-watt multi-frequency gyrotron in JAEA

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.

Development of long-pulse gyrotron for ITER EC system

Ikeda, Ryosuke; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Kobayashi, Takayuki; Moriyama, Shinichi; Sakamoto, Keishi

no journal, , 

no abstracts in English

Modification of ITER equatorial EC launcher design enhancing EC H&CD function

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.

Development of local control system for ITER gyrotron

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.

Study of sub-terahertz high power gyrotron for ECH&CD system of DEMO

Sakamoto, Keishi; Kariya, Tsuyoshi*; Oda, Yasuhisa; Minami, Ryutaro*; Ikeda, Ryosuke; Kajiwara, Ken; Kobayashi, Takayuki; Takahashi, Koji; Moriyama, Shinichi; Imai, Tsuyoshi*

no journal, ,