Electron impact single ionization of al+, Cd+ and Hg+

Electron Impact single ionization cross sections of Al+, Cd+ and Hg+ ions have been calculated in the Modified Binary Encounter Approximation. Accurate expression of σ_ΔE (cross section for energy transfer ΔE) and Hatree-Fock velocity distributions for the target electrons have been used throughout the calculations. For positive ions the focusing effects of the target ion on the incident electron have been incorporated in the calculations. The present results of single ionization cross sections are in excellent agreement with the experimental observations in the intermediate energy range. The calculated cross sections differs from the experimental results in the low energy regions because the present approximation not exhibit better result in the low energy regions, while the over-estimations of experimental results in the high energy regions shows that more theoretical calculations is required to understand the dynamics of the system.