Absorption Spectra of the Pink and Lewis—Rayleigh Afterglows of Nitrogen in the Vacuum-uv Region

Abstract

The absorption spectrum of the pink afterglow of nitrogen in the 1080–1900‐Å region has been studied in an attempt to determine the active substances responsible for the production of the afterglow. The Lewis—Rayleigh afterglow, which appears in conjunction with the pink afterglow was also studied, and various features of the two afterglows are compared. The afterglows were studied at room temperature and at liquid‐nitrogen temperature. Comparison was made between the emission spectra of an ordinary discharge of nitrogen and the absorption spectrum of the pink afterglow. Most of the absorption bands observed in the pink afterglow were found to originate in the higher vibration levels of the ground state of N₂, which indicates the presence of highly vibrating ground‐state molecules in activated nitrogen. The upper states of the absorption bands were determined to be the b, b′, g, j, m, o, q, r, and possibly other states. Bass' results are discussed and compared with those of the present work.