Kinetic studies of N₂ and N₂-SF₆ following proton excitation

Low intensity proton pulses have been used to excite pure N₂ and N₂-SF₆ mixtures. By accumulating time and wavelength resolved information on the fluorescence that arises from a very large number of pulses, we have obtained data that are free from effects due to superelastic collisions with electrons or other nonlinear effects such as the interactions between ions or excited neutral species. For N₂ the natural lifetimes of N₂(C ³Π_u) and N₂ ⁺(B ²Σ_u⁺) were determined by monitoring N₂(C ³Π_u→B ³Π_g) and N₂⁺(B ²Σ_u⁺→Χ ²Σ _g⁺) states, respectively. The quenching rates of N ₂(C ³Π_u) and N₂⁺(B ²Σ_u⁺) in different vibrational states by pure N₂ and by SF₆ were obtained. The addition of small concentrations of SF₆ altered the late time behavior of the N ₂(C ³Π_u→B ³Π_g) transitions, and the addition of much higher concentrations of SF₆ caused a large increase in the intensity of the 3371 Å (C→B) transition.