Vibrational excitation of N 2(C) and N 2(B) by metastable argon atoms and the determination of the branching ratio

Abstract

The reaction rates k C(υ′) for N 2(C, υ|t') (υ′ = 0, 1, 2, 3) and k B(υ″) for N 2(B, υ″) (0≤11) of the reaction: Ar( 3P 2,0) + N 2 å N 2(C, υ′) + Ar( k C(υ′)); å N 2(B, υ″) + Ar( k B(υ″)) were measured in a low pressure flowing afterglow (0.1 to 2 torr). The electronic branching ratio between N 2(B) and N 2(C) was determined to be: k B/ k C = 0.25 ± 0.15 [ k B = Σ υ″ k B(υ″), k C = Σ υ′ k C(υ′)]. It is shown that it is necessary to take into account both the quenching and the vibrational relaxation of N 2(B). The vibrational relaxation rate k υ(1) is determined to be 6.5 × 10 −12 cm 3 s −1.