Evolution of the electron temperature gradient mode in plasmas containing vortex and shear flows

Abstract

Evolution of the electrostatic potential of the electron temperature gradient (ETG) mode in a plasma with shear and vortex flows, as well as impurity ions, is investigated using a local fluid model. The governing equations are obtained through the Bayly nonmodal approach and solved numerically, so that the evolution of the electrostatic potential is obtained directly. It is found that the ETG mode intensity increases with flow shear, and an intensity minimum occurs when the eccentricity of the vortex flow is at a critical value. In general, impurity ions have a stabilizing effect on the flow-shear-induced secondary instability.