Short wavelength temperature gradient driven modes in tokamaks. II. Electron mode

Abstract

A short wavelength electron mode driven by toroidicity and electron temperature gradient has been found in stability analysis of tokamaks based on a fully kinetic, electromagnetic integral equation code. The mode exists in the regime (k⊥ρi)2>1 and propagates in the electron diamagnetic direction (electron mode with ωr>0). The instability vanishes in negative magnetic shear (s<0). In positive shear regime, the growth rate increases with s almost linearly, γ∝s. Neither electrons nor ions are adiabatic.