Plasma and Fusion Research
Volume 6, 1402135 (2011)
Regular Articles
- The Graduate University for Advanced Studies, 322-6 Oroshi-cho, Toki 509-5292, Japan
- 1)
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
Abstract
Non-local transport and electron temperature fluctuations triggered by supersonic gas puffing (SSGP) in high-temperature helical plasmas in the Large Helical Device (LHD) are reported. After a short-pulse SSGP, the core electron temperature increased while the edge electron temperature decreased. SSGP triggered a longer core temperature increase than that triggered by a small impurity pellet injection. The temperature profile, which was relatively flat inside the half minor radius before SSGP, became parabolic after non-local transport was triggered. Fluctuations were excited in the electron temperature signals around the half minor radius. The frequency of these fluctuations increased from ∼ 400 Hz to ∼ 1 kHz within ∼ 0.1 s and the amplitude decreased correspondingly. The temperature fluctuations inside and outside of the half minor radius had opposite phases. Magnetic fluctuations resonating near the half minor radius were observed simultaneously with the electron temperature fluctuations.
Keywords
fueling method, supersonic gas puffing, electron temperature fluctuation, non-local transport phenomenon, heliotron
Full Text
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This paper may be cited as follows:
Akiyoshi MURAKAMI, Junichi MIYAZAWA, Koji YASUI, Takanori MURASE, Naoki TAMURA, Hayato TSUCHIYA, Yoshiro NARUSHIMA, Tomohiro MORISAKI, Ryuichi SAKAMOTO, Hiroshi YAMADA and LHD Experiment Group, Plasma Fusion Res. 6, 1402135 (2011).