O4{− swarm data in O{in2

In this paper, we present the preliminary results from the calculation and measurement of the mobility of negative ions in oxygen, carried out with a pulsed Townsend, time-resolved apparatus. From these measurements and a previous work in this direction, we are led to suggest that the mobility of the negative ion under question corresponds to the O₄ ^- species. On the other hand, our calculations are based on an optimised Monte-Carlo algorithm using collision cross sections obtained from a JWKB approximation (Jeffreys-Wrentzel-Kramers-Brillouin) or taken from literature. Under the above assumption, we have been able to extend the range of measurement with our calculations and thus provide ion mobilities and reaction rate constants for E/N ranges below and above those covered by the experiment.