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Title: Research and Development on the Ion Cyclotron Range of Frequency Heating System in JT-60U

Abstract

Research and developments on the ion cyclotron range of frequency (ICRF) heating system in the JT-60 upgrade (JT-60U) are presented. The developments and experiences on the operation of the ICRF heating system contribute to its upgrade and to future ICRF heating systems in ITER. The ICRF heating system for JT-60U started operation in January 1992. RF power up to 7 MW for 1.1 sec at 116 MHz has been coupled to a plasma as a result of the developments described in this paper. New high power tetrodes having pyrolitic graphite grids for higher dissipation of screen and control grids were tested in the ICRF amplifier, and 1.7 MW of the output power at 131 MHz for 5.4 seconds was achieved. This was the highest power level for fusion research above 110 MHz in 1990. A pair of phased loop antenna arrays (2 x 2) showed sufficiently high coupling resistance. To keep the impedance matching between the antenna and the transmission line, a frequency feedback control (FFC) system was developed, and its effectiveness was proved to couple high power RF continuously to the variable plasma. In ITER, enhancement of dielectric loss tangent of ceramics due to neutron irradiation will limit powermore » injection capability of the antenna significantly. To solve this problem, an all-metal support (AMS) was developed in the JT-60U ICRF heating system as a substitute for a ceramic support of a central conductor of a coaxial antenna feeder in the ITER ICRF antenna.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2]
  1. Japan Atomic Energy Research Institute (Japan)
  2. Ibaraki University (Japan)
Publication Date:
OSTI Identifier:
20845865
Resource Type:
Journal Article
Journal Name:
Fusion Science and Technology
Additional Journal Information:
Journal Volume: 42; Journal Issue: 2,3; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1536-1055
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLIFIERS; ANTENNAS; CERAMICS; CONTROL; COUPLING; DIELECTRIC MATERIALS; FEEDBACK; HEATING SYSTEMS; ICR HEATING; IMPEDANCE; ION CYCLOTRON-RESONANCE; IRRADIATION; ITER TOKAMAK; JT-60 TOKAMAK; JT-60U TOKAMAK; MHZ RANGE; NEUTRONS; OPERATION; PLASMA; POWER TRANSMISSION LINES

Citation Formats

Moriyama, S, Fujii, T, Kimura, H, Anno, K, Yokokura, K, Shinozaki, S, Terakado, M, and Hiranai, S. Research and Development on the Ion Cyclotron Range of Frequency Heating System in JT-60U. United States: N. p., 2002. Web.
Moriyama, S, Fujii, T, Kimura, H, Anno, K, Yokokura, K, Shinozaki, S, Terakado, M, & Hiranai, S. Research and Development on the Ion Cyclotron Range of Frequency Heating System in JT-60U. United States.
Moriyama, S, Fujii, T, Kimura, H, Anno, K, Yokokura, K, Shinozaki, S, Terakado, M, and Hiranai, S. Sun . "Research and Development on the Ion Cyclotron Range of Frequency Heating System in JT-60U". United States.
@article{osti_20845865,
title = {Research and Development on the Ion Cyclotron Range of Frequency Heating System in JT-60U},
author = {Moriyama, S and Fujii, T and Kimura, H and Anno, K and Yokokura, K and Shinozaki, S and Terakado, M and Hiranai, S},
abstractNote = {Research and developments on the ion cyclotron range of frequency (ICRF) heating system in the JT-60 upgrade (JT-60U) are presented. The developments and experiences on the operation of the ICRF heating system contribute to its upgrade and to future ICRF heating systems in ITER. The ICRF heating system for JT-60U started operation in January 1992. RF power up to 7 MW for 1.1 sec at 116 MHz has been coupled to a plasma as a result of the developments described in this paper. New high power tetrodes having pyrolitic graphite grids for higher dissipation of screen and control grids were tested in the ICRF amplifier, and 1.7 MW of the output power at 131 MHz for 5.4 seconds was achieved. This was the highest power level for fusion research above 110 MHz in 1990. A pair of phased loop antenna arrays (2 x 2) showed sufficiently high coupling resistance. To keep the impedance matching between the antenna and the transmission line, a frequency feedback control (FFC) system was developed, and its effectiveness was proved to couple high power RF continuously to the variable plasma. In ITER, enhancement of dielectric loss tangent of ceramics due to neutron irradiation will limit power injection capability of the antenna significantly. To solve this problem, an all-metal support (AMS) was developed in the JT-60U ICRF heating system as a substitute for a ceramic support of a central conductor of a coaxial antenna feeder in the ITER ICRF antenna.},
doi = {},
journal = {Fusion Science and Technology},
issn = {1536-1055},
number = 2,3,
volume = 42,
place = {United States},
year = {2002},
month = {9}
}