Frequency and plasma condition dependent spatial structure of low frequency global potential oscillations in the TJ-II stellarator. (5th March 2019)

• Record Type: Journal Article
• Authors: Kobayashi, T.; Losada, U.; Liu, B.; Estrada, T.; van Milligen, B.Ph.; Gerrú, R.; Sasaki, M.; Hidalgo, C.
• Is Part Of: Nuclear fusion. Volume 59:Number 4(2019:Apr.)
• Publication Date: 2019-03-05
• Subjects: zonal flows -- plasma turbulence -- radial electric field; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ab0122
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: In this letter, we investigate the spatial structure of a low frequency global potential oscillation, which is likely ascribed as the low frequency zonal flows, in TJ-II laboratory plasmas. In two plasmas produced by different heating schemes (electron cyclotron resonance heating and neutral beam injection heating) and characterized by different mean radial electric field structures, frequency-space-decomposed spectra of the global potential oscillation are obtained. In both cases, the oscillatory field has a single-peaked potential structure and a dipole radial electric field structure. The oscillating structure depends on its frequency as well as on the heating scheme.