Secondary Reactions in a Gas Discharge

The pressure variations of H+, H2+, H3+, He+, and HeH+ ions emanating from an electrodeless discharge in pure hydrogen and in mixtures of hydrogen and helium have been measured. Mass analysis was accomplished with a ``strong-focusing'' mass spectrometer. The analysis of the results in hydrogen are discussed, as well as the alternative mechanisms for hydrogen dissociation. From the results in hydrogen-helium mixtures, a value of 0.37±0.15 has been obtained for the ratio k2′/k1′; where k2′ is the rate constant for reaction He++H2→HeH++Hand k1′ is the rate constant for the reaction H2++H2→H3++H.In addition, a value of 0.016±0.013 has been obtained for the ratio k3′/k2′, where k3′ is the rate constant for the reaction H2++He→HeH++H.