Ionization of Hydrogenic Systems by Positron and Electron Impacts

The ionizations of the 1S state of hydrogenic systems with a nuclear charge of Z = 2 and 3 have been carried out using the hybrid theory. This is a continuation of the work started earlier. The present results are compared with the published cross-sections for Z = 1 [Bhatia, A.K. 2025]. The distortion of the orbit is considered irrespective of the position of the incident particle, whether it is outside or inside the orbit. Only the distortion of the target orbit in the initial state is considered, but the distortion in the final state is not considered. Cross-sections decrease as the nuclear charge increases.