Simulation of lower-hybrid heating in a nonuniform plasma slab

A computer simulation study of the excitation of lower hybrid waves by external sources and the associated plasma heating is presented. A plasma slab with a nonuniform density profile is modeled with a two and one-half dimensional electrostatic particle code. Both a finite-length electrostatic antenna and a single wave exciter are considered. The frequency is chosen so that a wave conversion layer exists in the plasma. It is found that a narrow sheath is formed at the plasma edge and the dominant effect is surface electron heating within that region. Ponderomotive force effects as well as the nonlinear generation of harmonics and subharmonics also occur. A low amplitude lower hybrid wave is observed to be excited by the sources and propatates to the wave conversion layer where it is absorbed