Multi-frequency, megawatt-power gyrotron to facilitate a wide range of operations at ITER

Nuclear Fushion

article

Ryosuke Ikeda¹  Takahiro Shinya¹  Satoru Yajima¹  Taku Nakai¹  Takeru Ohgo¹  Masayuki Tsuneyama¹  Hibiki Yamazaki¹  Takayuki Kobayashi¹  Ken Kajiwara¹ 

[1] National Institutes for Quantum Science and Technology

关键词: gyrotron;    multi-frequency gyrotron;    ITER;    electron cyclotron heating and current drive;   

DOI  :  10.1088/1741-4326/accdeb

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

High-power (1 MW), long-pulse operations up to 300 s were demonstrated by multi-frequency oscillations at 170 GHz, 137 GHz, and 104 GHz. A multi-frequency gyrotron based on the design of the ITER gyrotron has been developed and studied. By redesigning the built-in mode convertor and internal mirrors of the ITER gyrotron, the internal scattered power of the gyrotron was reduced while maintaining the same output beam size and beam direction for the three frequencies. In addition, the mirrors of a matching optics unit were designed to efficiently couple the RF beam at 170 GHz, 137 GHz, and 104 GHz oscillations to a waveguide 50 mm in diameter, the same size that will be used in ITER. AnHE ₁₁ mode content of ∼94% was achieved for the three frequencies. Output powers of 1 MW at 170 GHz and 137 GHz, and 0.9 MW at 104 GHz were demonstrated up to 300 s. These oscillation frequencies can facilitate in a wide range of toroidal magnetic field operations at ITER, including plasma start-up and electron heating and current drive.

【 授权许可】

Unknown