Abstract
This Letter presents a quantum scattering theory of electron stimulated desorption and applies it to recent observations of ion angular distributions. The Franck-Condon desorption cross section is calculated in a three-dimensional reflection approximation. It is shown that the adsorption models suggested by Madey, Czyzewski, and Yates, which attribute anisotropy in the angular distributions to initial-state effects, are consistent with the theory and the data.