“…The total number of ion pairs created by completely stopping an alpha particle in several halocarbon gases varies from 1.09 to 1.44 times the total number produced in nitrogen (3). Since the ion current generated in the ionization chamber is a measure of the total number oi' ion pairs formed, the analytical sensitivity to uranium hexafluoride in a C 8 F 16 matrix should be comparable to, or moderately higher than, that obtained in nitrogen at the same pn~ssur~.…”