Transport equations for multispecies plasmas based on individual bi-Maxwellian distributions

Abstract

The authors have derived a closed system of transport equations for an anisotropic plasma of arbitrary degree of ionisation. The system is based on an anisotropic bi-Maxwellian species distribution function, and therefore, should provide a better description of flow conditions characterised by large temperature anisotropies. The method used to derive the transport equations is an extension of Grad's method and corresponds to a 16-moment approximation for the species distribution function. The relevant collision terms were calculated for an arbitrary inverse-power interaction potential and for a resonant charge exchange interaction between an ion and its parent neutral. In the collisionless limit, the system of equations reduces to the collisionless transport equations which include the effects of collisionless 'viscosity' and heat flow.