Intensity distribution of the rotational lines in the D 1Σ +u–X 1Σ +g(0, 0) band of the N 2+2 ion

Abstract

The vacuum UV emission spectrum of the D ¹Σ⁺_u–X ¹Σ⁺_g transition of the N²⁺₂ dication has been recorded photoelectrically at high resolution from an electric discharge through pure nitrogen and also through a 10% O₂–N₂ gas mixture.

Apparent breaking-offs in the rotational structure observed previously on photographic-plate spectra are not observed on the photoelectric spectra, so the intensity anomalies in plate spectra cannot result from predissociation of the N²⁺₂ ion. This agrees with observations made recently in laser photofragment experiments.