Relaxation of two-temperature plasma

Abstract

The relaxation process of a space uniform plasma composed of electrons and one species of ions is considered. For the varied initial electron and ion temperatures, the asymptotic behavior of the solutions, under ${m}_{e}{/m}_{i}\ensuremath{\ll}1,$ are studied. Special attention has been paid to the deviation of relaxation from the classical picture, the latter being characterized by a weakly nonisothermic situation ${T}_{e}\ensuremath{\gg}{(m}_{e}{/m}_{i}{)}^{1/3}{T}_{i}.$ An approach is developed for the detailed description of the relaxation. The perturbation of the electron distribution function, which has the character of a boundary layer for the cold electrons, is studied. The field of applicability of the well-known formulas for temperatures is extended and their corrections are obtained. The relaxation process of the two-temperature plasma is also considered numerically. A comparison of the results of the calculation with those of the asymptotic approach is made. The analytical results are confirmed by the numerical simulation results.