Plasma and Fusion Research

Volume 11, 2403098 (2016)

Regular Articles

Comparison between Full Wave and Ray-Tracing Calculations to Examine Scenarios for Electron Bernstein Wave Heating in LHD
Hiroe IGAMI, Atsushi FUKUYAMA1), Hiroshi IDEI2), Kazunobu NAGASAKI3), Yuki GOTO4), Shin KUBO, Takashi SHIMOZUMA, Yasuo YOSHIMURA, Hiromi TAKAHASHI, Toru I. TSUJIMURA and Ryohei MAKINO
National Institute for Fusion Science, 322-6 Oroshi-cho Toki 509-5292, Japan
1)
Department of Nuclear Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8530, Japan
2)
Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga 816-8580, Japan
3)
Institute of Advanced Energy, Kyoto University, Uji 611-0011, Japan
4)
Department of Energy Engineering and Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
(Received 30 November 2015 / Accepted 18 April 2016 / Published 13 July 2016)

Abstract

With the use of the density scale length and the magnetic field strength around the O-X mode conversion region in the LHD for 77 GHz EC waves, the full wave calculations by the TASK/WF2D code have been performed. The wave patterns obtained by full wave calculation have been compared with the trajectories obtained by multi ray tracing calculations. For the X-mode and the O-mode reflected near each cutoff, wave patterns obtained by full wave calculations and trajectories obtained by multi ray-tracing correspond to each other well. On the contrary, trajectories of the rays restarted at the high field side of the evanescent region between the plasma and the left handed cutoffs do not cover fully the wave patterns after the O-X mode conversion obtained by full wave calculations. Improvement of the manner to restart the ray-tracing is required. This improvement can provide a more precise view of the propagation of the EBWs and may contribute to examining scenarios for electron Bernstein wave heating.

Keywords

electron cyclotron resonance heating, electron Bernstein wave, full wave calculation, ray-tracing

DOI: 10.1585/pfr.11.2403098

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