AN ATTEMPT TO DETECT THE PRESENCE OF METASTABLE ATOMS IN ACTIVE NITROGEN BY LIGHT ABSORPTION

Abstract

In order to explain the nitrogen afterglow, Cario and Kaplan have assumed the presence of metastable 2D and 2P atoms in active nitrogen. The nitrogen emission lines at 1492 Å and 1742 Å have these metastable states as lower states, and should therefore be absorbed by active nitrogen. However, no absorption has been found by the writers. This leads to 1/6000% as an upper limit for the stationary concentration of metastable atoms in active nitrogen, which is compatible with the experiments. In order to account for the observed intensity of the afterglow, on the basis of Cario-Kaplan's theory, a lifetime of the metastable 2P atoms [Formula: see text] has to be assumed and a concentration of metastable molecules greater than 1/330%.