Linear wave propagation in plasmas

Abstract

Before proceeding to nonlinear phenomena we outline briefly several features of linear wave propagation in a nonuniform plasma. The amplitude of a wave in an inhomogeneous plasma may undergo large spatial variations due to zeros in the index of refraction which cause reflection and a superposition of oppositely propagating waves, or due to linear mode conversion. The wave form must be calculated carefully before the amplitude can be inserted into any nonlinear theory. Spatial amplitude gradients, for example, are responsible for the action of ponderomo-tive forces.