Time and space scales of electrical and gasdynamic non-uniformities in a non-equilibrium MHD plasma

The Saha equilibrium approximation and the temperature relaxation approximation to the MHD equations are investigated with regard to the analysis of the formation of nonlinear ionization non-uniformities and their evolution in a non- equilibrium MHD plasma. An analysis of characteristic relaxation times under typical plasma parameters is carried out to verify these approximations. Characteristic space scales of electron thermal conductivity and radiation are evaluated. These space scales determine the characteristic width of nonlinear ionization wave fronts, and are important for the application of numerical simulations.