Classical analysis of angular differential and total cross sections for charge transfer and ionization in He-like systems-helium atom collisions

A classical approach is used to determine the angular differential and total cross sections for charge transfer and ionization in He-like systems (Li+, Be2+, B3+, C4+, N5+, O6+) and helium atom collisions. It is found that the classical approach, i.e., classical trajectory Monte Carlo method (CTMC), gives adequate results for charge transfer and ionization in He-like systems and helium atom collisions. A model potential has been used for interactions of the active electrons with the projectile and target ion. We also observed sudden increase in the ionization cross sections at lower velocities, and it is explained in terms of quasi-molecular formation and multiple interactions. The behavior of angular differential cross sections calculated at very small scattering angle (<0.1°) in all systems shows a forward peak followed by an asymptotic fall with oscillatory structure at higher angles. These oscillations were classically interpreted in terms of swapping. The calculated cross sections are found in reasonable agreement with the available experimental and theoretical results.