Heat Transport Due to the Collisionless Tearing Instabilities

Abstract

Collisionless tearing instabilities and the associated electron heat transport are investigated by using a two-and-one-half dimensional particle simulation code. It is shown that a collisionless drift tearing instability saturates at a low amplitude and turns into a nonlinear pure tearing instability. The electron internal energy profile is flattened within the magnetic island. The electron heat conductivity obtained from the heat flow across the singular surface is proportional to W⁴ in the linear phase and to (dW⁄dt)W² in the nonlinear phase of the tearing instability. Here W is the half width or the magnetic island, and we treat the case only one tearing mode is unstable in the simulation. A theoretical model to explain these results is also presented.