The Role of Electron Spin in Atomic Collisions

Abstract

Experimental investigations of ion-atom collisions have evolved from “simple” total cross section measurements to studies of increasing complexity and sophistication. The detailed information obtained by advanced experiments provides a basis for an improved understanding of the various interaction mechanisms in a collision. One ultimate aim of these investigations might be a so-called perfect experiment in which the states of all collision partners are completely known prior to and after the collision (Bederson 1969, 1970). Experiments which employ an analysis of states and an identification of particle trajectories have been performed (see. e.g., Andersen and Nielsen 1982). For a perfect experiment it is necessary to specify all intrinsic properties of the collision partners, including the spin states. Investigations which explicitely study the conservation or the change of spin during the collision may reveal novel and otherwise unaccessible information about the collisional interaction. Corresponding experiments may be called spin-experiments.