Effects of radial electric field on suppression of electron-temperature-gradient mode through multiscale nonlinear interactions. (31st August 2016)

• Record Type: Journal Article
• Authors: Moon, Chanho; Kaneko, Toshiro; Itoh, Kimitaka; Ida, Katsumi; Kobayashi, Tatsuya; Inagaki, Shigeru; Itoh, Sanae-I; Hatakeyama, Rikizo
• Is Part Of: Plasma physics and controlled fusion. Volume 58:Number 10(2016:Oct.)
• Publication Date: 2016-08-31
• Subjects: ETG mode -- multi-scale nonlinear coupling -- radial electric filed -- turbulence suppression; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/0741-3335/58/10/105007
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: Turbulence in fluids and plasmas is ubiquitous in Nature and in the laboratory. Contrary to the importance of the 'scale-free' nature of cascade in neutral fluid turbulence, the turbulence in plasma is characterised by dynamics of distinct length scales. The cross-scale interactions can be highly non-symmetric so as to generate the plasma turbulence structures. Here we report that the system of hyper-fine electron-temperature-gradient (ETG) fluctuations and microscopic drift-wave (DW) fluctuations is strongly influenced by the sign of the gradient of the radial electric field through multiscale nonlinear interactions. The selective suppression effects by radial electric field inhomogeneity on DW mode induce a new route to modify ETG mode. This suppression mechanism shows disparity with respect to the sign of the radial electric field inhomogeneity, which can be driven by turbulence, so that it could be a new source for symmetry breaking in the turbulence structure formation in plasmas.