Photodetachment spectrum of hydrogen negative ion near a spherical surface

The semi-classical closed orbit theory is applied to study photodetachment of H-near an elastic spherical surface for a z-polarized laser light. It is assumed that similar to the outgoing detached-electron waves from the source, waves propagate from an image of the source behind the surface. We then calculate the classical action for those trajectories that are perpendicular to the surface. The spherical effects in total photodetachment cross section are controlled by curvature kappa of the surface. For zero curvature, our results match with the plane wall case while for a large curvature the results become the asymptotic value of the cross section recently published.