Excitation of infrared auroral emissions in collisions of H+ and H with N2

Abstract

Cross sections for emission of the N2+(A²Πu − X²Σg+) Meinel (2, 0) and the N2 (B³Πg − A³Σu+) first positive (1P) (3, 1) bands in 0.5–25 ke V H+ and H impact on N2 are reported. It is shown that, in a hydrogen aurora, H+ and H impact make comparable contributions to the Meinel band intensity but that neutral hydrogen impact is the predominant source of 1P emission. The vibrational distribution of N2+ A²Πu formed in 25 ke V H+ and H impact with v′ = 2–5 is shown to be in good agreement with the prediction of a simple Franck‐Condon model.