Single-electron capture by highly charged ions colliding with atomic and molecular hydrogen

The ratio between the cross sections for single-electron capture by highly charged ions colliding with atomic and molecular hydrogen has been investigated within the framework of the Bohr-Lindhard theory. It is shown that σ(H2)σ(H) can be represented as a universal function of the inherent scaling parameter over a wide range of ion energy and charge states. Generally, the ratio is different from the often-assumed value of 2.