Ionization of Argon and Neon by Electron Impact

The "ionization efficiency curve" for singly charged argon is found to have at least one inflection of the type first observed by E. O. Lawrence for mercury. The relative probabilities of forming singly and doubly charged argon and neon are tabulated. Careful examination of the initial portions of the "ionization efficiency curves" for singly charged neon and argon and doubly charged argon shows the "tails" to be largely characteristic of the ionization cross section and not purely caused by spread in electron energy as often has been assumed.