Transport coeffcients in crossed E and B fields: empirical relations and nonconservative collisional effects

Abstract

Hydrodynamic charged particle transport coefficients in gases in orthogonal electric and magnetic fields are investigated analytically, using approximate balance equations generated by momentum transfer theory. Emphasis is placed upon both the explicit and implicit effects of non-particle-conserving collisions, including ionisation and attachment, and identifying measurable transport coefficients. Generalised Einstein relations linking diffusion coefficients with differential mobilities are ultimately obtained. The spatial variation of the charged particle mean energy is shown to play a central role in these considerations. The accuracy of the approximate analytic theory is tested for certain model interaction cross sections against highly accurate results obtained by "multiterm" solution of Boltzmann's equation.