Condensed Matter Physics, 2015, vol. 18, No. 3, p. 33001
DOI:10.5488/CMP.18.33001
arXiv:1510.06528
Title:
On relaxation phenomena in a twocomponent plasma
Author(s):

V.N. Gorev
(Oles Honchar Dnipropetrovsk National University, 72 Gagarin Ave., 49010 Dnipropetrovsk, Ukraine)
,


A.I. Sokolovsky
(Oles Honchar Dnipropetrovsk National University, 72 Gagarin Ave., 49010 Dnipropetrovsk, Ukraine)
,


Z.Yu. Chelbaevsky
(Oles Honchar Dnipropetrovsk National University, 72 Gagarin Ave., 49010 Dnipropetrovsk, Ukraine)

The relaxation of the temperatures and velocities of the components of a quasiequilibrium twocomponent homogeneous completely ionized plasma is investigated on the basis of a generalization of the ChapmanEnskog method applied to the Landau kinetic equation. The generalization is based on the functional hypothesis in order to account for the presence of kinetic modes of the system. In the approximation of a small difference of the component temperatures and velocities it is shown that relaxation really exists (the relaxation rates are positive). The proof is based on arguments that are valid for an arbitrary twocomponent system. The equations describing the temperature and velocity kinetic modes of the system are investigated in a perturbation theory in the square root of the small electrontoion mass ratio. The equations of each order of this perturbation theory are solved with the help of the Sonine polynomial expansion. Corrections to the known Landau results related to the distribution functions of the plasma and relaxation rates are obtained. The hydrodynamic theory based on these results should take into account a violation of local equilibrium in the presence of relaxation processes.
Key words:
distribution function, ChapmanEnskog method, relaxation rate, Sonine polynomials, kinetic equation, kinetic modes, fully ionized plasma
PACS:
02.30.Rz, 05.20.Dd, 52.25.Dg
