Photodetachment of H- near a metal surface

The photodetachment cross section of H- near metal surface is investigated based on the semiclassical closed orbit theory. It is found that the metal surface has significant influence on the photodetachment process. It is found that the cross section of photodetachment undergoes a transition from a staircase structure to a smooth oscillation when the incoming photon energy increases, When the photodetached electron is trapped in image potential well, the detachment spectrum displays an irregular staircase structure which corresponds to Coulomb-like image states. While the photon energy is higher than the image state potential, the spectrum becomes a smooth oscillation.