Density collapse and fluctuation observed in poloidally rotating plasma on TU-Heliac

Yutaka Tanaka, Sumio Kitajima, Mamiko Sasao, Hiroyasu Utoh, Hiroshi Aoyama, Keisuke Iwazaki, Hajime Umetsu, Keiichi Ishii, Atsushi Okamoto, Takashi Kobuchi, Shigeru Inagaki, Yasuhiro Suzuki, Hiromi Takahashi

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2 Citations (Scopus)

Abstract

The ohmic heated plasma in TU-Heliac was biased by a hot-cathode to drive E × B poloidal rotation. Coincident measurements of the line density and ion saturation currents revealed the existence of density collapse accompanied by fluctuation in the poloidally rotating plasma. The radial density profiles just before and after the collapse were estimated. The steep density gradient vanished with the density collapse. The power spectra of the fluctuation were calculated from the ion saturation current obtained with a high-speed triple probe. The frequency of fluctuation was compared to the E × B poloidal rotation frequency, where the fluctuation appeared with density collapse. The fluctuation frequency was 2 to 3 times the rotation frequency. This suggested that the poloidal mode number of fluctuation was m =2 or 3.

Original languageEnglish
Article numberS1055
JournalPlasma and Fusion Research
Volume3
DOIs
Publication statusPublished - 2008 Jan 1

Keywords

  • Density collapse
  • Fluctuation
  • Heliac
  • Poloidal rotation
  • Stellarator

ASJC Scopus subject areas

  • Condensed Matter Physics

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    Tanaka, Y., Kitajima, S., Sasao, M., Utoh, H., Aoyama, H., Iwazaki, K., Umetsu, H., Ishii, K., Okamoto, A., Kobuchi, T., Inagaki, S., Suzuki, Y., & Takahashi, H. (2008). Density collapse and fluctuation observed in poloidally rotating plasma on TU-Heliac. Plasma and Fusion Research, 3, [S1055]. https://doi.org/10.1585/pfr.3.S1055