Dynamic stabilization of drift waves by electron temperature modulation

The effect of a small, periodic, time-dependent modulation of the electron temperature on the linear stability of a weakly inhomogeneous magnetoplasma is considered. Such a modulation may be produced by microwave heating of electrons. First, a general theory of the instability of collisionless drift waves with a small periodic modulation of the distribution function is derived. This is then used to deduce conditions for the dynamic stabilization of a variety of drift instabilities. It is found that the collisionless instabilities may be stabilized when the beating of an unstable drift wave with the temperature modulation is subject to an additional damping mechanism. No stabilizing effect has been found for the resistive drift mode described by a fluid approximation.