skip to main content

Title: Regulation of electron temperature gradient turbulence by zonal flows driven by trapped electron modes

Turbulent transport caused by electron temperature gradient (ETG) modes was investigated by means of gyrokinetic simulations. It was found that the ETG turbulence can be regulated by meso-scale zonal flows driven by trapped electron modes (TEMs), which are excited with much smaller growth rates than those of ETG modes. The zonal flows of which radial wavelengths are in between the ion and the electron banana widths are not shielded by trapped ions nor electrons, and hence they are effectively driven by the TEMs. It was also shown that an E × B shearing rate of the TEM-driven zonal flows is larger than or comparable to the growth rates of long-wavelength ETG modes and TEMs, which make a main contribution to the turbulent transport before excitation of the zonal flows.
Authors:
; ;  [1] ; ;  [2]
  1. Tokyo Institute of Technology, Tokyo 152-8550 (Japan)
  2. National Institute for Fusion Science, Gifu 509-5292 (Japan)
Publication Date:
OSTI Identifier:
22252868
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ELECTRON TEMPERATURE; EXCITATION; REGULATIONS; SIMULATION; TEMPERATURE GRADIENTS; TRAPPED ELECTRONS; TURBULENCE