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 He 2+ on H and H 2 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 He 2+ beam. The results for the He 2+ -H are in good agreement with different theoretical predictions, although none of the theories reproduces the experimental data over the entire energy range.