Plasma waves in a nonideal plasma

This paper shows how the concepts commonly used for a Debye plasma-Landau damping, collisional damping, short-range and long-range collisions, and plasma waves-must be revised to describe a nonideal electron-ion plasma. The degrees of freedom of a nonideal plasma are divided into collective and individual. The increase and saturation of the fraction of collective degrees of freedom as the coupling constant increases is discussed. The Tatarskii approach for a system of coupled oscillators makes it possible to model the collective degrees of freedom of a nonideal plasma by a set of Langevin oscillators in a thermostat. The correlation energy and the energy of the plasma waves are found. The concepts developed here made it possible to determine the dispersion of the plasma waves and their damping. The effect of damping on the discrepancy between the position of the maximum of the dynamic structure factor and the real part of the solution of the dispersion equation is considered. The effective collision frequency of the individual degrees of freedom (the electrons) is estimated, taking into account both short-range pairwise scattering and scattering at plasma waves. (C) 1998 American Institute of Physics. [S1063-7761(98)00903-2].