Charge-exchange processes of hydrogen ions with Hg atoms at keV energies

A search for the production of the 2p2 3Pe state of H- has been made by crossing a H-(1s2) ion beam of energies E<140 keV with a thermal Hg beam inside a static electric field. The formation of H-(2p2) ions and their subsequent decay to neutral H(1s) results in a feature on the angular distribution of the neutral particles produced in electron loss of the ground-state H-(1s2) ions. The absence of such a feature sets an upper limit of 10-20 cm2 to the cross section for formation of the 2p2 3Pe state. Differential (with respect to angle) charge-transfer cross sections for scattering in the angular range 3°<<15°as well as the small-angle forward cross sections 10 and -10 for hydrogen ions passing through Hg vapor are presented.