Plasma surface impedance for coupling to the ion-cyclotron and ion-Bernstein waves

Analytic expressions for the surface impedance for coupling radio-frequency energy into a slab plasma at the ion-cyclotron range of frequencies are obtained. For the case of fast-wave coupling, the modification due to finite ny, corresponding to azimuthal variation in cylindrical geometry, is included. For this case (ny≠0), subtle and important changes in the fast-wave accessibility condition are introduced by the gradient effects. For the slow-wave coupling to the ion-Bernstein modes, the plasma surface impedance exhibits critical dependence upon the electron density and ion temperature at the plasma edge.