摘要: The measurement of the energy and the angular distributions of excited atomsdesorbed from ion-bombarded solids has been of long-standing interest since these distributions hold the key to understanding the excitation and deexcitat... 展开 The measurement of the energy and the angular distributions of excited atomsdesorbed from ion-bombarded solids has been of long-standing interest since these distributions hold the key to understanding the excitation and deexcitation processes. Although many investigators have experimentally determined the energy distributions of atoms ejected in various excited states, all these measurements have been confined to a single angle of emission. Corresponding theories and models have thus concentrated on the velocity dependence of the excitation probability. In 1954, Hagstrum proposed that for excited atom fractions, the velocity dependence of the excitation probability should follow an exp(-A/a) velocity perpendicular is the component of escape velocity perpendicular to the surface and A/a is the deexcitation coefficient. This relation has been used to describe experimental distributions except for the low velocity regime where surface binding energy effects are suggested to alter this dependence. 收起