A theoretical imaging method for the photodetachment of H− near a reflecting surface

Abstract

Total photodetachment cross section of H− near a reflecting wall was studied recently by Yang et al using closed-orbit theory (2006 J. Phys. B: At. Mol. Opt. Phys. 39 1855). The main effect of a reflecting wall was shown to induce an oscillation in the cross section. In this paper, we study the photodetachment of H− near a reflecting wall using a theoretical imaging method, which is very different from the method of closed-orbit theory. The theoretical imaging method enables us to derive the total and differential photodetachment cross sections in a straightforward way. We considered both a soft wall case and a hard wall case, they differ by the values of phase loss when reflecting the detached-electron waves. The result of Yang et al for the total photodetachment cross section is the asymptotic limit of our formula for the soft wall case. We also calculated the detached-electron flux distributions on a screen placed at a large distance from the negative ion. The distributions display strong interference patterns. Such interference patterns are similar to those in the photodetachment microscopy experiments.