Interactions between neutral dissociation and ionization continua in N2O

Abstract

Autoionized Rydberg states converging to the à ²Σ⁺ and B̃ ²Π states of N₂O⁺ are shown to be predissociated into neutral fragments. The decay to excited neutral fragments is observed by their fluorescence in the visible and ultraviolet regions of the spectrum. These decay channels are in competition with autoionization, which was shown in a previous study to yield unexpectedly large numbers of low energy electrons. On the basis of the striking similarity between the fluorescence excitation and the threshold photoelectron spectra, models are presented which connect dissociative channels to the production of threshold electrons. Ionization of dissociating neutral states and Rydberg states converging to the ground electronic state of N₂O⁺(X̃ ²Π) are suggested as being responsible for the production of low energy electrons. The distribution of photoelectron energies resulting from such autoionization channels are calculated.