On the Theory of Bulk Viscosity of Cold Plasmas and Thermodynamics of Alkali-Noble Gas Cocktails

By solving the kinetic equation for ionization-recombination processes in cold plasmas for temperatures much lower than the first ionization potentials, we derive an explicit expression for the complex polytropic index, as well as bulk viscosity.

The obtained result for the ionization-recombination relaxation time reveals that the Mandelstam-Leontovich approximation for the frequency dependence of the bulk viscosity is actually an exact solution in the case of cold plasmas.

We systemize also explicit general formulae for the thermodynamics of the alkali-noble cocktails in the same low temperature plasma approximation, allowing the Schwarzschild criterion on convectional instability to be derived, too.

All these general results are applicable for cold stellar, interstellar and laboratory plasmas.

Additionally, the wave heating of the inner solar atmosphere up to the solar transition region is studied thoroughly, and it is found that the magnetic diffusivity, heat conductivity, shear- and bulk viscosities all play an almost equally important part in the wave damping, therefore none of them can be omitted in realistic considerations of heating of the solar atmosphere.