Energy-momentum description of electrostatic waves in magnetoactive plasmas

Abstract

The physical mechanism of the energy-momentum transfer governing the propagation of electrostatic waves in collisionsless plasmas is presented. Plasma is supposed to be immersed in external uniform crossed magnetic and electric field. The equilibrium plasma, determined by a stationary distribution of charged particles, is assummed to be generally anisotropic and weakly nonuniform. The changes in macroscopic quantities (in the kinetic energy of perpendicular and parallel motion, etc.) due to the self-consistent wave-particle interaction are derived. It is shown, that the corresponding dispersion equation is identical with the energy-momentum balance equations expressed in the wave frame. A new expression of the energy of waves (plasmons) is given, which ensures the energy-momentum balance equations to be mutually independent equations. This differs from the usual expression of the wave energy leading to energy-momentum balance equations which are not mutually independent.