Observation of low-energy Z oscillations in total electron-capture cross sections for bare projectiles colliding with H and H2.

Abstract

An oscillatory charge dependence of total electron-capture cross sections has been observed for fully stripped projectiles having charge $6<~Z<~10$ incident on H and ${\mathrm{H}}_{2}$ at collision energies below 3.0 keV/amu. The oscillations are attributed to the discreteness of the projectile final-state spectrum and the strong selectivity of the capture process at a given energy. Relative maxima in the cross sections occur for odd projectile charge in the case of H, and for even projectile charge in the case of the ${\mathrm{H}}_{2}$ target. This shift is explained in terms of a Landau-Zener curve-crossing picture of the electron-transfer collision.