Vacuum ultraviolet emission by active nitrogen. II. The excitation of singlet and triplet states of carbon monoxide by active nitrogen

The addition of small amounts of carbon monoxide to active nitrogen induces strong emission of the CO fourth positive bands, (A1Π—X1∑+), which extends up to v' = 8. The kinetic behaviour of the emission is closely similar to that of the Lyman-Birge-Hopfield emission of N2, comprising terms proportional to [N]2/([M] + γ) and [N]3/[M], the latter being enhanced in argon carriers. It is shown that CO(A1Π) is excited by efficient energy transfer from N2(a1Πg) and is removed predominantly by radiation. Excited triplet states of N2 excite triplet states of CO but they do not contribute significantly to singlet CO emission.