Emission Spectra of Nitrogen in the Vacuum Ultraviolet

Abstract

The emission spectra of nitrogen have been photographed in the vacuum ultraviolet under high resolution. Selected bands of the b′¹Σ_u⁺—X¹Σ_g⁺ and the a¹Π_g—X¹Σ_g⁺ systems have been analyzed and new rotational and vibrational constants obtained. The observed Λ‐type doubling of the a¹Π_g state was used to determine that the F_c′ doublet component lies above the F_d′ component. Rotational perturbations were found in the v=0 level of the a¹Π_g state, and in the v=0 and 1 levels of the b′¹Σ_u⁺ state. Vibrational perturbations were found in the v=4, 5, and 6 levels of the b′¹Σ_u⁺ state and a new predissociation at v=4, J=9 was observed. The new predissociation limit lies at 13.233 ev and is equally compatible with either the 9.756 ev or the 7.373 ev ground‐state dissociation energy.