Yield of electronically excited CN molecules from the dissociative recombination of HNC+ with electrons.

The authors have studied CN(B-X) and CN(A-X) emissions produced by the dissociative recombination of HNC+ ions with thermal electrons in a flowing afterglow experiment. A separate drift tube study showed that the reaction Ar(+)+HCN, the precursor reaction used in the flow-tube experiment, produces predominantly HNC+ rather than the more energetic HCN+ isomer. Models simulating the ion-chemical processes, diffusion, and gas mixing in the afterglow plasma were fitted to observed position dependent CN(A-X) and CN(B-X) band intensities.

Yield of excited CO molecules from dissociative recombination of HCO+ and HOC+ ions with electrons.

The authors have investigated CO band emissions arising from the dissociative recombination of HCO(+) and HOC(+) ions with thermal electrons in a flowing afterglow plasma. The quantitative analysis of the band intensities showed that HCO(+) recombination forms the long-lived CO(a (3)Pi) state with a yield of 0.23+/-0.

Yield of electronically excited N2 molecules from the dissociative recombination of N2H+ with e-.

Quantitative spectroscopic observations of the N2 first positive band system (N2(B 3Pig-A 3Sigmau+))/electron in a recombining N2H+ flowing-afterglow plasma indicate that a substantial fraction of the product N2 molecules are formed in one or more of the low-lying triplet states, B 3Pig, A 3Sigmau+, and W 3Deltau. The total measured N2(B-A) emission intensity from N2(B,v' > or = 1) is equivalent to a yield of (19 +/- 8)%. The effect of rapid collision-induced transitions between states of the triplet manifold is discussed.