Acoustic mode driven by fast electrons in TJ-II Electron Cyclotron Resonance plasmas. (31st August 2016)

• Record Type: Journal Article
• Authors: Sun, B. J.; Ochando, M. A.; López-Bruna, D.
• Is Part Of: Europhysics letters. Volume 115:Number 3(2016:Aug.)
• Publication Date: 2016-08-31
• Subjects: 52.35.Fp -- 52.55.Hc -- 52.35.Py; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/115/35001
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: Intense harmonic oscillations in radiation signals are commonly observed during Electron Cyclotron Resonance (ECR) heating in TJ-II stellarator plasmas at low line-averaged electron density, . The frequency agrees with acoustic modes. The poloidal modal structure is compatible with Geodesic Acoustic Modes (GAM) but an toroidal structure is detected. The modes are found in the proximity of low-order rationals of the rotational transform ( in this work) and are excited by fast-electron populations, but they disappear at the onset of -islands rotation.