Ionization current measurements and the energy required to form an ion pair in γ-ray irradiated gases

Abstract

Ionization current measurements in cobalt-60 γ-ray irradiated gases have been used to determine the average energy required to form an ion pair (W value) in a series of gases. Using well-established values of W for six gases (H₂, He, air, N₂, Ar, and C₂H₂), two methods of determining W from further experimental data have been devised. Correlation of W with observed ionization current data has been achieved using (a) a modified version of the Bethe equation, and (b) available stopping powers. W values for a number of other gases have been determined by both treatments, and the results from each method compared.