Electron capture into He+(2p) in low-energy collisions of He2+ with atomic and molecular hydrogen

Absolute state-selective electron capture cross sections for charge transfer into the 2p state of He+ in collisions of He2+ on H and H2 have been measured in the impact energy range of 0.2-2 keV amu-1. The low-energy beams have been produced by retarding a fast He2+ beam. The results for the He2+-H are in good agreement with different theoretical predictions, although none of the theories reproduces the experimental data over the entire energy range.