Lifetime and Quenching of CO(a 3Π) Produced by Recombination of CO2 Ions in a Helium Afterglow

Rapid dissociative recombination of CO2+ in a flowing, helium afterglow has been shown to be an efficient source of CO in the a 3Π metastable state. Ions produced by mixing CO2 with He(23S) recombine to produce a CO metastable afterglow with a number density as great as 109 cm−3. Monitoring of the (a 3Π—X 1Σ) Cameron transition in CO was used to study the lifetime and quenching of CO(a 3Π) by CO2, N2, NO, and He. Recombination of CO 2 + also produces CO in the d 3Δ and a′ 3Σ states.