Momentum and Energy Exchange between Beams of Particles Interacting by Yukawa-Type Potentials

Abstract

A statistical theory of the momentum and energy exchange between beams of particles interacting by Yukawa-type potentials is presented. A theoretical description is given for the slowing down of the beams, the thermalization and heating of the beams, and the establishment of the isothermal state in the beams. The associated collision integrals are evaluated, with consideration of the velocity dependence of various Coulomb logarithms. The kinetic processes are shown to depend crucially on whether the relative velocity of the beams is supersonic or subsonic. The theory is applicable to (i) beams of charged and neutral particles interacting by a Coulomb potential screened by bound electrons, and (ii) beams of charged particles interacting by a Coulomb potential screened by free charges. In the region of low energies, the results are applicable to the components of collision-dominated ionized gases and plasmas, and represent an essential contribution to the transport theory of collision-dominated media with nondivergent Coulomb interactions.