Variation Principle for Nonlinear Wave Propagation

Abstract

It is now widely recognized that one of the most important nonlinear effects which arise associated with the propagation of a moderately strong high-frequency wave is a modification of the density profile of the plasma. Such a profile modification occurs as a result of the action of the ponderomotive force of the high-frequency fields. When the plasma is confined by a static magnetic field, the force acting along the magnetic field is most important and the balance of the ponderomotive force and the pressure gradient force in this direction determines the statieaary density profile. The profile modification in, turn affects the properties of the wave propagation, and the entire problem has to be nolved self-consistently. In general, this problem requires a solution of highly complicated partial differential equations with appropriate boundary conditions.

Supported in part by the Scientific Research Fund of the Ministry of Education in Japan.