Ion recombination in dense gases

Abstract

Ion recombination is considered in a wide range of medium properties in dense gases. A dependence of the ion recombination rate on background gas density is found. Three ranges of different recombination kinetics regimes are defined: collisional, diffusion and intermediate. Their borders are defined. A dependence of the recombination rate on the ion Coulomb nonideality is established, contrary to the idea that there is no such dependence, though it is weaker than in the collisional regime. The dependence can be interpolated as exponentially drop-down curves in the whole range the nonideality parameter values. The slope of the decay decreases with an increase of the background gas density, in other words, with the decrease of the ion free path. Extrapolation of this trend to high densities permits to suggest that the dependence is of no importance in liquids. However, the effect can be remarkable in the range of gas pressures from one up to several dozen atmospheres.