The rate coefficients for a number of thermal energy charge-transfer reactions are obtained with a recently completed selected ion flow tube (SIFT). The ion-molecule reactions studied involve Ar+ and Ar2+ with a variety of neutral molecules including 02, CS2, C02, S02, H20, H2S, NH3, NO, SF6, CH4, N20, N02, and CO. The relative magnitudes of the observed rate coefficients are not in accord with an energy resonance model which requires favorable Franck-Condon factors. Furthermore, we find that the dimer ion reaction rate constant is not always greater than that of the monomer with a specific neutral although there is greater phase space in the case of the dimer where the dissociative channel leads to a three-body final state. However, the proximity of the recombination energy of Ar+ and Ar2+ to a band in the photoelectron spectra of the neutral appear to explain the relative rates of the monomer and the dimer reactions with a specific neutral.
A new laser technology that achieves nearly 100-nm quasi-continuous tuning with only injection-current control in a four-section grating-coupler sampled-reflector laser was used to detect CO and CO(2) simultaneously in room-temperature gas mixtures. The same grating-coupler sampled-reflector laser was used to perform in situ measurements of CO, H(2)O, and OH in the exhaust gases of a CH(4)-air flame. This laser is being evaluated for inclusion in a multispecies combustion-emissions exhaust-analysis sensor, and its operational characteristics as they have an impact on gas sensing are described. Preliminary results suggest that this single laser can be used to replace multilaser sensor configurations for some combustion-emissions monitoring applications.
A unique pulsed fast oxygen atom source has been used to investigate the interactions between 8 km/s oxygen atoms and CO, CO2, and CH4. Absolute cross sections for direct and chemiexcitation of the short wave infrared bands of reaction products have been evaluated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.