Ionisation processes in collisions of open-shell atoms. I. Fluorine atom collisions with inert gases and molecules

Results of an electron spectroscopy study of ionisation processes in collisions of F atoms with He, Ne, O 2 and CO 2 at low keV energies are presented. It is shown that in case of the He and Ne targets ionisation is partly due to population of singly-excited autoionising states of the 1 D nl series and partly due to another mechanism which results in the production of a continuous electron energy distribution and becomes particularly important at high energies. A discussion in terms of the molecular orbital model is presented and indicates that quasimolecular Auger ionisation must be the other F + production channel. In the case of molecular targets the authors observe a direct ionisation channel and also dissociative ionisation via the population of 2 D nl autoionising states of fragment O atoms.