Multichannel Penning detachment of H- from excited Li and Ca atoms

We develop theoretical cross sections for Penning detachment of H- from 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 ground state and those that leave the target excited after the collision, namely, H-+Li(3s), H-+Li(3p), H-+Li(3d), and H-+Ca(4s5s1Se). Our results show that, in general, Penning detachment is enhanced when several decay channels are open and that the target is left preferentially in the nearest excited state. copyright 1997 The American Physical Society