On the Dynamical Aspect of the Dissociative Attachment in Electron-Molecule Collisions

Abstract

In the field of electron-molecule collisions, the impulse approximation and the resonant formalisms have very often been presented as relevant to two extreme opposite cases for the vibrational-excitation process. However, the dissociative-attachment (DA) process has not been investigated from an impulse point of view. The examination of the impulse approximation for vibrational excitation shows that it contains terms (excitation to closed vibrational channels) that qualitatively correspond to the DA process. A very simple estimate of the DA cross-section is then derived. It allows for a qualitative discussion of the process in the e--H2 and e--HCl systems which confirms the impulse character of the DA process in these two systems.