Reactions of Gaseous Molecule Ions with Gaseous Molecules. IV. Experimental Method and Results

Abstract

This paper is concerned with a detailed description of quantitative studies of certain secondary reactions involving simple molecules and ions that occur in the ion source of a mass spectrometer. It is found that the phenomenological reaction cross sections for reactions of the type P++R→S++···are independent of the temperature of the gas in the ion source, and vary inversely with the square root of the product of the ion repeller field strength and the reduced mass of the reactant ion-reactant molecule pair. For the reactant ion (P+) a rare gas, hydrogen, nitrogen, or carbon monoxide, and the resultant molecule (R) hydrogen, the cross sections for formation of the secondary ion, S+=PH+, are found to be one or two orders of magnitude greater than the ordinary, kinetic theory collision cross sections for similar atoms and molecules.