Dissociative excitation of NO2 by electron impact

Abstract

Electron-impact-induced vacuum ultraviolet emissions are measured for NO2, a species important to discharge phenomena and ozone decomposition in the Earth's atmosphere. A calibrated spectrum for 100 eV incident electrons is presented, along with cross sections for strong emission features between 80 and 160 nm. The dominant N i (2p3 4S°–3s 4P) emission at 120.1 nm is compared with that of N2 and used to provide an absolute calibration for all measured cross sections. In addition, 10–300 eV excitation functions for the N i (120.1 nm) and O i (130.4 nm) emissions are presented and interpreted. Comparisons are made with similar measurements of related species, in particular N2O and NO. Of interest, it was found that, on average, the variation in the intensity of oxygen and nitrogen emissions could be reasonably explained by the difference in the number of constituent oxygen and nitrogen atoms in each target.