MOMENTUM-TRANSFER THEORY OF NONCONSERVATIVE CHARGED-PARTICLE TRANSPORT IN MIXTURES OF GASES - GENERAL EQUATIONS AND NEGATIVE DIFFERENTIAL CONDUCTIVITY

In this paper we develop general equations for the momentum transfer t heory (MTT) for swarms of particles in mixtures of gases including the effect of nonconservative (reactive) collisions. MTT equations for me an energy, drift velocity, diffusion tensor components, and rate coeff icients are derived for different degrees of approximation including t he hydrodynamic limit and small swarm to gas particle mass ratio. Spec ific formulas were developed for the criteria for negative differentia l conductivity (NDC) in mixtures of gases with elastic collisions only and for a single gas with reactions. The criteria and the numerical c alculations are in excellent agreement, showing that NDC can be induce d by light atomic constituents in purely elastic collisions and also b y ionization and attachment.