Return To: Session TH2 - Turbulence, Flows, Streamers
Prev Page: (TH2/3) Role of Zonal Flow in Turbulent Transport
Next Page: (TH2/5) Gyrokinetic Simulations of Tokamak Microturbulence

(TH2/4) Nonlinear Features of the Electron Temperature Gradient Mode and Electron Thermal Transport in Tokamaks

P. K. Kaw¹⁾, R. Singh¹⁾,J. G. Weiland^2)
 
1) Institute for Plasma Research, Bhat, Gandhinagar 382428, India
²⁾ Department of Electromagnetics, Chalmers University of
Technology, S-41296, Gothenburg, Sweden

Abstract.  Analytical investigations of several linear and nonlinear features of ETG turbulence are reported. The linear theory includes effects such as finite beta induced electromagnetic shielding, coupling to electron magnetohydrodynamic modes like whistlers etc. It is argued that nonlinearly, turbulence and transport are dominated by radially extended modes called `streamers'. A nonlinear mechanism generating streamers based on a modulational instability theory of the ETG turbulence is also presented. The saturation levels of the streamers using a Kelvin Helmholtz secondary instability mechanism are calculated and levels of the electron thermal transport due to streamers are estimated.

Read the full paper in PDF format.