Close coupling approach for heavy particle collisions with an excited atom: transitions between n=3 states in He

The close coupling (CC) equations in the impact parameter (IP) representation are considered. Calculations for transitions in the 3s–3p–3d He atom system induced by collisions with single charged ions were carried out. Results are compared with those obtained in the frame of the Born approach. The effects of stepped transitions, normalization, channel coupling and their dependence on interaction strength are discussed.