MULTICHANNEL PENNING DETACHMENT OF H- FROM EXCITED LI AND CA ATOMS

We develop theoretical cross sections for Penning detachment of H- fro m excited Li and Ca atoms for impact energies between 25 meV and 20 eV . We examine two kinds of cases: those that leave the target in its gr ound state and those that leave the target excited after the collision , namely, H- + Li(3s), H- + Li(3p), H- + Li(3d), and H- + Ca(4s5s S-1( e)). Our results show that, in general, Penning detachment is enhanced when several decay channels are open and that the target is left pref erentially in the nearest excited state.