Statistical distribution of ionization yields in gases from electron irradiation

The integral equation for the probability density of the number of ions produced in matter as a result of complete degradation of electrons is solved numerically using a Fourier transform. Data are presented with reference to argon, which show that if inner-shell contributions are neglected, the probability distribution becomes Gaussian around a source energy of 5 keV. However, results obtained including the contributions from $L$-shell and Auger electrons indicate that a normal distribution of ions can be expected only at higher energies.