Vibrational Distributions od SO^+(A^2Π_i) Produced from Dissociative Ionization of SO-Containing Molecules in a Helium Flowing Afterglow

Abstract

Emission spectra resulting from the reactions of He (23S) , He', and He2+ with S02, SOC12, SOBr2, S02C12, and S02FCI have been measured in a helium flowing afterglow in order to examine dissociative-ionization processes leading to SO' (A2IIi) . Although the SO+ (A2Hi'X2Hr) emission system was observed from the reactions of He' with S02, SOC12, and S02C12, it was absent from those of He' with SOBr2 and S02FCI. The vibrational distributions of SO" (A) decreased nearly exponentially with increasing v' for all the three reactions. The effective vibrational temperatures of SO'(A) were determined to be 3320A}230, 4620A}760, and 3100A}300 K for S02, SOC12, and S02C12, respectively.