Generation of superthermal electrons interacting with waves in lower-hybrid range of frequency revisited

The problem of quasilinear diffusion of plasma electrons, resonantly interacting with waves in lower-hybrid range of frequency launched from the exterior, is examined within a self-consistent one-dimensional homogeneous model. An analytical solution is obtained, which allows the derivation of a simple formula for the plasma current in terms of the parameters characterizing the spectral distribution of the RF power source. The major outcome is a dramatic sensitivity of the plasma current to the presence of a small, high-N/sub /// component in the RF power source spectral distribution, in agreement with previous numerical calculations.