Threshold photodetachment in a repulsive potential

TL;DR

This paper reports the first experimental observation of a new threshold behavior in photodetachment of K- caused by a repulsive polarization interaction, supported by a semiclassical model predicting exponential energy dependence.

Contribution

The study presents the first experimental evidence of a novel threshold behavior in photodetachment due to repulsive polarization, along with a semiclassical model explaining the exponential energy dependence.

Findings

Observation of threshold behavior in K- photodetachment

Development of a semiclassical model for the cross section

Confirmation of exponential energy dependence

Abstract

We report on the first experimental observation of a new threshold behavior observed in the 5g partial channel in photodetachment of K-. It arises from the repulsive polarization interaction between the detached electron and the residual K(5g) atom, which has a large negative dipole polarizability. In order to account for the observation in the K(5g) channel, we have developed a semiclassical model that predicts an exponential energy dependence for the cross section. The measurements were made with collinear laser-ion beams and a resonance ionization detection scheme.