Trajectory Calculations of Electron Stimulated Desorption of Positive and Negative Ions

Abstract

An important issue in ESDIAD (electron stimulated desorption ion angular distribution) of positive and negative ions from surfaces concerns the influence of final-state effects on the trajectories of desorbed ions. It is believed that the initial repulsive forces propelling ESD ions from surfaces often originate from 2 hole repulsive states which act along the original chemical bond direction[l]. However, final state effects, including image field effects, reneutralization, and coadsorbed impurity ions can influence the measured ion desorption angles by distorting the ion trajectories and thus the angular distributions. Several recent papers have described classical trajectory calculations in which the image force [2,3] and reneutralization [4] were included.