ON LANDAU DAMPING IN HOT EQUILIBRIUM PLASMAS .1. LONGITUDINAL OSCILLATIONS ALONG AN EXTERNAL MAGNETIC-FIELD

A relativistic theory of longitudinal oscillations in hot, magnetized, isotropic equilibrium plasmas is presented. The special theory of relativity enters the description, with the requirements that the particle masses are depending on the particle velocities that themselves are limited by the speed of light. Using the relativistic Maxwell-Boltzmann-Jüttner distribution correctly describing the equilibrium state of a plasma, the dispersion relations for subluminal, as well as superluminal waves, are formulated using the Trubnikov representation. Besides a discussion of the dispersion curves, it is shown mat superluminal oscillations are always undamped, whereas for subluminal waves the relativistic generalization of the Landau damping is derived. It is shown that the resulting damping rates are significantly lower than those obtained with the nonrelativistic theory. © 1995 American Institute of Physics.