P-wave photodetachment from Au- in a static electric field

Photodetachment from negative ions initially bound in s-states has been studied in a static electric field. A 10 keV ion beam was sent through a region with fields of up to 1.5 kV/cm applied parallel to the beam direction. A pulsed dye laser beam perpendicular to the ion beam photodetached the ions. The cross sections were measured by detecting the resulting fast neutrals with a gated channeltron detector. Polarization dependent electric field oscillations were observed on the p-wave detachment cross section of Au- near the threshold at 18620.2 cm-1. A simple theory for calculating the oscillatory structure is presented. Good agreement is found between the data and the theory for laser polarizations both parallel to and perpendicular to the static electric field