On heat conduction in multicomponent, non-Maxwellian spherically symmetric solar wind plasmas

A generalized expression for the steady state heat flux in multicomponent, moderately non-Maxwellian spherically symmetric plasmas is presented and discussed. The plasma is considered to be describable by the first six moments of the distribution function f_a of each plasma component a. Higher order fluid equations based on Fokker-Planck theory are derived for these moments of f_a. As an illustration, the authors discuss the electron radial heat flux in a spherically symmetric, moderately nonequilibrium, quiet (steady state) two-fluid solar wind plasma.