Formation of excited states of N2 from ground state nitrogen atoms

Abstract

Recent kinetic studies of the emission by singlet states (a¹Π_g, a′¹∑^– _u) and triplet states (B³Π_g, B′³∑^– _u) of N₂ in active nitrogen are compared. These stress the importance of relaxation by N₂ within the singlet and triplet manifolds as compared with intersystem crossing, which is induced efficiently by N, but not by N₂. Two body association involving inverse predissociation via the ⁵∑⁺ _g state populates N₂(a¹Π_g), v= 6 and (B³Π_g), v= 13. Relaxation of the former is the dominant source of the higher levels of N₂(a¹Π_g) but at pressures above 1 Torr the triplet manifold is predominantly populated by three body combination into the N₂(A³∑⁺ _u) state.