Monte Carlo simulation of electron detachment properties for ions in oxygen and oxygen:nitrogen mixtures

Abstract

Electron detachment properties of ions in pure oxygen and oxygen:nitrogen mixtures have been studied by a Monte Carlo technique for the reduced electric fields up to 350 Td (1 Td = 10−17 V·cm2). Swarm parameters were calculated for unexcited and vibrationally excited ions taking into account vibrational transfer and relaxation, charge transfer and electron detachment. The cross sections for vibrational transfer and relaxation in collisions between ions and O2 molecules were calculated on the basis of the statistical approach that had been successfully used in our previous work to simulate the effect of vibrational excitation and the effect of electric field on electron detachment. Good agreement between the calculated detachment rate and available measurements in oxygen were obtained over a wide range of reduced electric fields without using adjusted parameters. The method was used to calculate detachment rates in air and in some other oxygen:nitrogen mixtures and to study the effect of gas temperature on electron detachment.