Current profile control and application to advanced tokamak/steady state plasma operations by lower hybrid waves

Ide, Shunsuke

Purazuma, Kaku Yugo Gakkai-Shi, 81(3), p.167 - 170, 2005/03

https://doi.org/10.1585/jspf.81.167

Non-inductive current drive (CD) by radio-frquency waves in the lower hybrid range of frequency (LHRF) is one of most powerful scheme to drive a plasma current and control the current profile of a tokamak plasma externally. This paper reviews recent achievement of CD by LHRF (LHCD) in tokamak experiments with special emphasis on steady state tokamak operation and profile control in an advanced tokamak.

Measures against the damage of the antenna mouth of JT-60U LHRF system

Ishii, Kazuhiro*; Seki, Masami; Shimono, Mitsugu; Terakado, Masayuki; Igarashi, Koichi*; Takahashi, Masami*

JAERI-Tech 2003-079, 22 Pages, 2003/10

JAERI-Tech-2003-079.pdf:3.01MB

In JT-60U, the study of current drive by radio-frequency (RF) waves in lower hybrid range of frequency (LHRF) has been done as one of research and development works aiming at steady state operation of tokamaks. The main subject of hardware and technology development in this study is to develop a high power LHRF antenna, the main component of the system. The LHRF antenna is set closely to plasma to efficiently inject RF power into it. The LHRF antenna normally receives heat loads from the plasma, and it is required to inject high RF power. Then, it has become a problem that the antenna mouth was melted by excessive heat loads from plasma or it was melted and deformed by RF discharges. As a counter measurement against this, the LHRF antenna has been conditioned to improve its stand-off voltage capability. Furthermore, by monitoring the temperature of the LHRF antenna, adjusting its position, developing a injection method of power modulation even for current drive, and setting an arc sensor which picks up the RF discharge, the damage of the antenna mouth has been suppressed.

Development and operation of the Lower Hybrid Range of Frequency system on JT-60U

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

https://doi.org/10.13182/FST02-A240

no abstracts in English

Electron cyclotron resonance discharge cleaning by using LHRF system on JT-60U

Ushigusa, Kenkichi; Seki, Masami; Suganuma, Kazuaki; Toyoshima, Noboru; Ikeda, Yoshitaka

Fusion Engineering and Design, 45(2), p.137 - 144, 1999/05

https://doi.org/10.1016/S0920-3796(99)00002-2

no abstracts in English

ECR discharge cleaning on JT-60U

Ikeda, Yoshitaka; Ushigusa, Kenkichi; Seki, Masami; Suganuma, Kazuaki;

JAERI-Research 97-075, 15 Pages, 1997/10

JAERI-Research-97-075.pdf:0.89MB

no abstracts in English

Design of a 5GHz window in a lower hybrid r.f. system

Maebara, Sunao; Ikeda, Yoshitaka; Seki, Masami; Imai, Tsuyoshi

Fusion Engineering and Design, 26, p.343 - 349, 1995/00

https://doi.org/10.1016/0920-3796(94)00200-Q

no abstracts in English

LHRF current drive experiments on JT-60

Imai, Tsuyoshi; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Naito, Osamu; Yoshida, Hidetoshi; Seki, Masami; Itami, Kiyoshi; Nagashima, Keisuke; Uehara, Kazuya; Nagashima, Takashi

Kaku Yugo Kenkyu, 65(SPECIAL ISSUE), p.99 - 118, 1991/03

no abstracts in English

Construction and testing of the new multijunction LHRF launcher for JT-60 upgrade

Seki, Masami; Ikeda, Yoshitaka; *; Imai, Tsuyoshi; ; Yokokura, Kenji; Sawahata, Masayuki; Suganuma, Kazuaki; Sato, Minoru; *; et al.

Fusion Technology 1990, p.1060 - 1064, 1991/00

no abstracts in English

Volt-second saving by lower hybrid current drive in JT-60

Naito, Osamu; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Imai, Tsuyoshi; Kimura, Haruyuki; JT-60 Team

Nuclear Fusion, 30(6), p.1137 - 1139, 1990/06

https://doi.org/10.1088/0029-5515/30/6/015

The volt-second consumption of the Ohmic primary circuit is reduced by lower hybrid current drive duringthe current rise phase. Most of the lower hybrid power is con- sumed in compensating the resistive voltage of typically 0.8 V.Up to 2.5 V s of flux is saved by 2 MW x 2.5 s of lower hybrid power, which could be projected to several tens of volt-seconds in ITER class reactors. In most cases, for lower hybrid assisted current ramp-up discharges the safety factor q can pass the value qa = 3 without causing any disastrous MHD instabilities leading to a major disruption.

Development of super high power klystron-system for JT-60 LHRF heating and current drive

Imai, Tsuyoshi; Ikeda, Yoshitaka; Maebara, Sunao; Fujii, Tsuneyuki; Sakamoto, Keishi; Saigusa, Mikio; Honda, Masao; Yokokura, Kenji; Sawahata, Masayuki; Uehara, Kazuya; et al.

Fusion Engineering and Design, 13, p.177 - 185, 1990/00

https://doi.org/10.1016/0920-3796(90)90098-Q

no abstracts in English