O ^-₂ Ion Mobility in Dense Supercritical and Near Critical Argon Gas

Abstract

Understanding the properties of the motion of ions in gases and liquids is of great interest both from a fundamental as well as a practical point of view. Information on the scattering processes between a massive charged particle and the atoms of a host medium and on its microscopic structure can be deduced from the analysis of the ion motion. at very low density (N ≤ 10^-5 atoms nm-³) the scattering cross sections for momentum transfer relative to the interaction between an ion and an atom or a molecule are extracted from ion drift mobility (μ) data within the Boltzmann formalism of kinetic theory ¹. on the other hand, hydrodynamic interactions explain the ion motion in high density liquids ². There is, however, a lack of information in the intermediate density region, important because of the transition from the kinetic to the hydrodynamic regime. Moreover, understanding the ionic conduction can explain the prebreakdown and breakdown phenomena in dielectric fluids.