Abstract
The vibrational excitation of N2 molecules by resonance scattering of electrons of 2-3 eV is calculated with a compound state model, that is on the assumption that the mechanism is e+N2 to N2- to N2+e'. The complex electronic energy of the N2- ion is treated parametrically, the essential new point being that Gamma /h(cross), the autoionization rate, varies with the separation of the nuclei. The variation comes from the dependence of the angular momentum barrier on the energy of the emitted electron. Good agreement is obtained with the experimental energy dependence of cross sections with reasonable values of the parameters. Calculations have also been done to illustrate the transition to the impulse limit as Gamma is increased, and to the compound molecule limit as Gamma is reduced.