Electron impact ionisation of Fe XXIV ions

Abstract
The electron impact ionisation cross section of Fe XXIV is calculated by two methods, both making allowance for excitation-autoionisation and for radiative decay. The breakdown of LS coupling for this ion does not seriously affect the results but the effects of radiative decay are to reduce the excitation-autoionisation contribution by a significant amount. The results obtained omitting radiative decay are up to 25% larger than those given by the semi-empirical formula of Burgess and Chidichimo (1983), which also omits this process.