Plasma and Fusion Research
Volume 8, 2402073 (2013)
Regular Articles
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
- 1)
- Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
- 2)
- Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Greifswald, Germany
Abstract
High harmonic electron cyclotron resonance heating (ECH) can extend the plasma heating region to higher density and higher β compared to the normal heating scenario. In this study, the heating characteristics of the second-harmonic ordinary (O2) and third-harmonic extraordinary (X3) modes and the possible extension of heating regime are experimentally confirmed. At the same time, a comparative study using ray-tracing calculation was performed in the realistic three-dimensional configuration of the Large Helical Device. The O2 mode heating showed a 40% absorption rate even above the X2 mode cut-off density. The X3 mode heating using powerful 77 GHz gyrotrons demonstrated an increase of about 40% in the central electron temperature in the plasmas at β-value of about 1%. These results were quantitatively explained to some extent by ray-tracing calculations.
Keywords
electron cyclotron heating, ECH, high harmonic heating, gyrotron, absorption rate, ray-tracing, LHD
Full Text
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This paper may be cited as follows:
Takashi SHIMOZUMA, Hiromi TAKAHASHI, Shin KUBO, Yasuo YOSHIMURA, Hiroe IGAMI, Masaki NISHIURA, Shinya OGASAWARA, Ryohei MAKINO, Hiroshi IDEI, Nikolai B MARUSHCHENKO, Yuri TURKIN and Takashi MUTOH, Plasma Fusion Res. 8, 2402073 (2013).