Ionization cross sections by electron impact on halogen atoms, diatomic halogen and hydrogen halide molecules

The binary-encounter-Bethe (BEB) model has been used to calculate electron-impact ionization cross sections of Br, I, Br-2, I-2, HCl, HBr and HI. The BEB single ionization cross sections of Br and I presented here agree generally well with experimental results with respect to low- and high-energy behaviour and peak values. In view of this generally good agreement, the BEB cross sections of the other molecules, for which no experimental results are available, are also expected to be reliable. We compare our results with those from alternative models, where available. We also explore the use of effective core potentials for the heavy atoms of these molecules within the context of the BEB model.