Systematics of the single and double electron scattering contributions to charge exchange

The authors examine the general charge transfer reaction in the first and second Born approximations for arbitrary initial (Z T ,n'l'm') and final (Z P ,nlm) states. The salient features of the first (single scattering) and second (single and double scattering) Born total cross sections are pointed out, with special emphasis on the possible dominance and detection of the double scattering contribution in charge exchange processes. The single scattering contribution is treated exactly and the double scattering contribution approximately as in a previous paper by the authors (1980). Representative distributions of cross sections are presented as a function of impact velocity and the various quantum numbers, thereby illustrating the characteristic trends of the two contributions.