Formation of excited states of N2 from ground state nitrogen atoms

Recent kinetic studies of the emission by singlet states (a1Πg, a′1∑–u) and triplet states (B3Πg, 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(a1Πg), v= 6 and (B3Πg), v= 13. Relaxation of the former is the dominant source of the higher levels of N2(a1Πg) but at pressures above 1 Torr the triplet manifold is predominantly populated by three body combination into the N2(A3∑+u) state.