The Dissociation ofH2+by Electron Impact

Abstract

The collision (in Born approximation) of electrons with ${\mathrm{H}}_2^{+}$, in which the molecule is raised from the ground state to the lowest lying repulsive state and is therewith dissociated, is discussed as the simplest example of a collision resulting in molecular dissociation. Both the angular distribution of dissociated protons and the excitation of the molecule to a state of definite angular momentum are investigated, and the connection between them is made clear. For the former, rules giving the dominant characteristics of the angular distribution are stated and illustrated by an example; for the latter, a detailed example is given which brings out the scope of the Franck-Condon principle and shows that near the energy of dissociation that gives the Franck-Condon maximum of the scattering amplitude there are also other sizable maxima, i.e., the Franck-Condon principle has a sort of fine structure.