Kinetic Theory of Plasmas, Including Dynamical Screening

Abstract

In Chapter 6 collisions in plasmas were described by means of the Landau equation. The Landau collision integral turned out to be doubly divergent: for small interaction distances, because the assumed weakness of interaction does not apply, and for large interaction distances because of the long range of the Coulomb potential. The theory was based on binary collisions and did not take into account the electrostatic screening of colliding particles due to the polarization of the intermediate plasma. This situation was remedied in Chapter 6 by providing the integral with a lower and an upper cut-off. This procedure leads, however, to a rough approximation, which is only satisfactory when the Coulomb logarithm is very large. In the present chapter dynamical screening, i.e. screening of moving charged particles is incorporated in the kinetic equation. Also the possibilities for the construction of a completely convergent collision integral are discussed.