151. Difference in Electron Transport between Co- and Counter-NBI-Heated Plasmas in the Inward-Shifted Configurations on LHD
- Author
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Hisamichi Funaba, Byron J. Peterson, Katsumi Ida, Shin Kubo, Kenji Tanaka, Ryuichi Sakamoto, Shigeru Inagaki, Nobuyoshi Ohyabu, Satoru Sakakibara, Yasuhiko Takeiri, Sadayoshi Murakami, Yoshiro Narushima, Takashi Shimozuma, Yoshio Nagayama, Kiyomasa Watanabe, Junichi Miyazawa, Kenichi Nagaoka, and Masaki Osakabe
- Subjects
Nuclear and High Energy Physics ,Materials science ,020209 energy ,Mechanical Engineering ,Magnetic confinement fusion ,02 engineering and technology ,Electron ,Plasma ,Thermal diffusivity ,01 natural sciences ,Neutral beam injection ,Flattening ,010305 fluids & plasmas ,Large Helical Device ,Nuclear Energy and Engineering ,Physics::Plasma Physics ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electron temperature ,General Materials Science ,Atomic physics ,Civil and Structural Engineering - Abstract
In the low-density plasmas of the Large Helical Device, the shape of the electron temperature profile changes depending on the direction of the tangential neutral beam injection (NBI) when the magnetic axis position is inward-shifted at R = 3.50 m. Core flattening was observed in plasmas heated by counter-NBI. The electron thermal diffusivities in co-NBI and counter-NBI-heated plasmas are compared. The diffusivity becomes large at the central region in the case of counter-NBI. This result shows that the flattening in the electron temperature profile is not caused simply by a change in the power deposition only. Some magnetic fluctuations are seen during counter-NBI. On the other hand, it is a promising feature that the electron thermal diffusivity at the peripheral region does not increase with the heating power in co-NBI plasmas.
- Published
- 2004