ABSTRACT
This chapter begins with a treatment of the temporal and spatial propagation of small-amplitude waves. It considers nonlinear processes associated with propagations of large-amplitude waves; these include a formation of solitary waves, self-trapping, and self-focusing. The chapter discusses two nonlinear effects: solitary waves and ponderomotive forces. With the aid of perturbation-theoretical calculations, one can in principle analyze a temporal or spatial echo to any order of external disturbances. Contrary to the case of a temporal propagation, the spatial propagation of the plasma wave takes place symmetrically with regard to the positive and negative x directions. The plasma-wave echo phenomena have been investigated experimentally both for the electron plasma oscillation and for the ion-acoustic wave. A large-amplitude plasma wave is applied to the plasma; its amplitude may then remain almost constant the distribution function, on the other hand, is modulated by the wave potential; it becomes time dependent.
