Abstract
Electron-loss cross sections are calculated in the free-collision model (FCM) for the energy range 14 keV/amu to 105 keV/amu. Care is taken to use accurate electron-target scattering cross sections, the basic input to the FCM. To get some indication of the inherent accuracy of the free-collision assumption comparison is made with exact results in a first Born model problem. Also investigated is the efficacy of the closure approximation for those loss processes involving excitation of the target. While He(23S) and Li(22S) may be regarded as containing only one 'active' electron, the 2s electron, at low impact energies, calculation shows that the tightly bound 1s electron make very substantial contributions at high energies. In the case of many-electron projectiles, cross sections for electron loss leading to particular final electronic states of the ionised projectile are given.