Transport Properties Of Two Temperature Partially Ionized Plasmas

A simplification of the Chapman-Enskog method for the calculation of transport properties of two-temperature, partially ionized gas mixtures in a magnetic field is presented. The simplication is achieved by exploiting the fact that the electron mass is much smaller than that of any other constituent of the gas. A systematic study is presented of the tensor coefficients for the electron electrical conductivity, thermal conductivity, and thermal diffusion. The interplay between the degrees of ionization and magnetic field in determining the sign of the transverse electron thermal diffusion coefficient has been examined. Simple formulas for the thermal diffusion coefficients in the presence of magnetic field have been obtained. The unified theory of Kihara and Aono for charged particle interactions was applied to obtain improved values of the transport coefficients when the number of particles in a Debye sphere is not large. These have been compared with theories based on a cut-off Coulomb potential, and on a shielded-Coulomb potential. It was found that the unified theory and the shielded-Coulomb theory are in close agreement. Mixture rules were given for all three transport coefficients, including the case when there is a magnetic field present. Simplifications introduced into the Chapman-Enskog method were also demonstrated in obtaining the transport coefficients of the heavy particles of a three component, two temperature plasma. (Author).