Vibrational Excitation of Diatomic Molecules by Electron Impact

Abstract

Vibrational excitation cross sections of diatomic molecules have been calculated using the Born approximation by including the polarization interaction between the incident electron and the molecule. Because of the divergence of the polarization potential at the origin, a cutoff procedure must be used. Four different cutoff methods have been examined, and the excitation cross sections are not very sensitive to the choice of the cutoff parameters. For the nonpolar molecules, inclusion of the polarization term increases the cross sections by an order of magnitude or more over the previous calculations, while in the case of the CO molecule, the contribution from the polarization term is comparable to that from the monopole—dipole interaction.