Observation of luminescent spectra in low energy ion-neutral collisions. Progress report for period June 1, 1975--May 31, 1976

The experimental investigations reported were directed toward obtaining information on the energy partitioning among internal energy states of the product species resulting from collisions between positive ions and neutral molecules at relative kinetic energies below about 500 eV. Two types of inelastic collision processes have been studied: electron exchange and atomic rearrangement. The data, which were obtained by direct observation of emission spectra resulting from the decay of excited collision products, have been used for product identification and for the determination of state distributions and absolute excitation cross sections. The state distributions have been compared to those predicted from theoretical models, and have also been used to elucidate reaction dynamics. The nature of the potential energy curves (and surfaces) for the species involved has been shown to play an important role in determining energetics and excitation cross sections. One class of dissociative charge transfer (electron exchange) process has been found to be an efficient mechanism for creating a population inversion in a discharge laser cavity. The state distributions and excitation cross sections obtained in this work have provided microscopic details of the collisions that occur in the complex environment of a discharge laser cavity. (auth