The response of short-scale density fluctuations to the activity of beta-induced Alfvén eigenmodes during strong tearing modes on EAST tokamak. (20th July 2015)

• Record Type: Journal Article
• Authors: Cao, G M; Li, Y D; Li, Q; Sun, P J; Wu, G J; Hu, L Q
• Other Names: collab.
• Is Part Of: Physica scripta. Volume 90:Number 8(2015:Aug.)
• Publication Date: 2015-07-20
• Subjects: short-scale density fluctuations -- collective scattering -- beta-induced Alfvén eigenmodes -- tearing modes; Physics -- Periodicals; 530.05
• DOI: 10.1088/0031-8949/90/8/085604
• Languages: English
• ISSNs: 0031-8949

Abstract

Abstract: Beta-induced Alfvén eigenmodes (BAEs) during strong tearing modes (TMs) have been frequently observed in fast-electron plasmas of EAST tokamak. The dynamics of the short-scale ( density fluctuations during the activity of BAEs with strong TMs has been preliminarily investigated by a tangential CO2 laser collective scattering system. The results suggest the active, but different, response of short-scale density fluctuations to the TMs and BAEs. In the low-frequency (0–10 kHz) part of density fluctuations, there are harmonic oscillations totally corresponding to those of TMs. In the medium-high frequency (10–250 kHz) part of density fluctuations, with the appearance of the BAEs, the medium-high frequency density fluctuations begin to be dominated by several quasi-coherent (QC) modes, and the frequencies of the QC modes seem to be related to the changes of both TMs and BAEs. These results would shed some light on the understanding of the multi-scale interaction physics.