Relaxation processes in spatially homogenous plasma with account for quadratic terms

Properties of a completely ionized two-component spatially homogenous electron-ion plasma are investigated on the basis of the Landau kinetic equation. The generalization is made on the basis of a generalized Chapman-Enskog method, which allows us to investigate the temperature and velocity relaxation. Our previous works are devoted to the obtaining of corrections of higher orders in the small electron-to-ion mass ratio to the results of the local equilibrium assumption (LEA) in the framework of the linear relaxation. This work is devoted to the investigation of quadratic terms in small relaxation parameters. At some stage of the system evolution the leading order in the mass ratio of such terms gives a contribution to the plasma component distribution functions (CDF) and to the temperature and velocity relaxation rates which can be comparable with the above-mentioned corrections in the framework of the linear relaxation.