Recent Upgrading of ECRH System and Studies to Improve ECRH Performance in the LHD
1 National Institute for Fusion Science, Toki, 509-5292, Japan
2 Department of Energy Engineering and Science, Nagoya University Nagoya, 464-8603, Japan
3 Institute of Advanced Energy, Kyoto University 611-0011 Uji, Japan
4 Research Institute for Applied Mechanics, Kyushu University 816-8580 Kasuga, Japan
a Corresponding author: igami@LHD.nifs.ac.jp
Published online: 12 March 2015
This paper reports the recent status of the ECRH system in the LHD and introduces the experimental results that suggest the reasonable effects of the wave-plasma interaction in the plasma boundary including outside the LCFS. With increasing the available ECRH power, ECRH/ECCD have been performed in higher density target plasmas where the mode coupling between the O-mode and the X-mode caused by the magnetic shear occurs for long distance in the low density region of the plasma boundary including the ergodic layer outside the LCFS. In such a case, the incident polarization should be set by taking into account the mode coupling effect. Moreover, the refraction in the boundary region should be considered for accurate numerical prediction of the wave trajectory and power absorption with use of the ray-tracing calculation.
© Owned by the authors, published by EDP Sciences, 2015
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