Geometric optics of lower hybrid waves in nonuniform plasmas

Propagation of lower hybrid waves is discussed in nonuniform plasma in the geometric optics limit. One advantage of a ray description of RF propagation is that it can be applied to realistic plasma configurations which are quite complicated, where a precise solution of the field structure would be impractical (and in all probability, unmeaningful). The article considers the effects of gradients on the wave propagation which can lead to the formation of caustics and cusps and which significantly modify the results of plane wave analysis