Intensity measurements in emission of 18 Vegard–Kaplan bands of N2

Abstract

The Vegard–Kaplan band system of nitrogen was excited by running a low-current discharge through a pure xenon–nitrogen mixture contained in a 6-liter spherical bulb of a discharge tube. Photoelectric measurements of the relative intensities of 18 bands (λ 2340–4324 Å) have been made using a 1-m Ebert–Fastie spectrometer. These measured band intensities were used along with Franck–Condon factors qν′ν″ and r centroids [Formula: see text] to study the variation of the electronic transition moment Re(r) with internuclear separation r. It was found that over the measured range from r = 1.23 to 1.43 Å that Re(r) could be represented by[Formula: see text]A "smoothed" set of band strengths [Formula: see text] was determined from this expression for all the observed bands of the Vegard–Kaplan system.