Direct measurement of ion temperature and poloidal rotation velocity with Doppler spectroscopy during Bifurcation in Tohoku University Heliac

Toshihiro Oku, Sumio Kitajima, Keiichi Ishii, Yu Sato, Jo Tachibana, Satoshi Koike, Kosuke Shimizu, Atsushi Okamoto, Hiromi Takahashi, Masakazu Takayama, Shigeru Inagaki

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Electrode biasing experiments were carried out in the Tohoku University Heliac (TU-Heliac) to investigate the role of ion viscosity maxima in the L-H transition. To investigate the relation between ion viscosity and poloidal Mach number, the driving force of the poloidal rotation and poloidal rotation velocity must be normalized by the ion temperature Ti and ion pressure Pi. Doppler spectroscopy was used to directly measure the ion temperature and the poloidal rotation velocity. Therefore, the dependence of the ion temperature and poloidal rotation velocity on the electrode current was obtained. The relation between the normalized driving force of the poloidal rotation and the poloidal Mach number Mp was non-linear. Bifurcation phenomena in the poloidal rotation appeared at Mp ~ -3. These results qualitatively agreed with the neoclassical theory.

Original languageEnglish
Article number3402051
JournalPlasma and Fusion Research
Issue numberSpecialIssue2
Publication statusPublished - Jan 1 2014


All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

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