Kinetic Theory of Inhomogeneous Plasmas Situated in RE Fields

The stability effect that an RF electric field imposes on drift instabilities in a magnetized plasma, inhomogeneous in density and temperature, is investigated in the kinetic approximation, taking account of the finite ion Larmor radii. Stabilization of drift instabilities is examined in three frequency ranges:ω/k∥ < υth,i, υth,i < υ/k∥ < υth,e, and ω/k∥ > υth,e, where k∥ is the component of the wave vector parallel to the applied dc magnetic field, and υth, e and υth, i are the electron and ion thermal speeds, respectively. It is found that stabilization is most effective for the medium phase-velocity range, where the drift instability, driven by streaming electrons, is strongest and sensitive to the ratio Ln/LT, where Ln and LT are the density and temperature gradient scale lengths, respectively.