State-selective electron capture in collisions of He²⁺with H

Charge transfer into He+ (nl) states (n <5) in collisions (2-13 keV amu-1) of He2+ on atomic hydrogen has been studied by means of photon emission spectroscopy. State selective electron capture cross sections into the degenerate He+ (4l) states have been determined by deconvoluting the intensity distribution of the He II (n = 4 --> n = 3) emission along the total ion-beam path inside the collision chamber. They are compared with theoretical results, especially with the large-basis set extended atomic orbital calculations of Fritsch. Generally good agreement with these extended calculations is found. However, the structures in the theoretical cross sections for capture into the non-dominantly populated n = 4 states are not observed experimentally.