Electron Impact Cross Sections for Argon

A reasonably complete set of phenomenological discrete and ionization cross sections for argon is given using combinations of data and theoretically meaningful extrapolations of the generalized oscillator strengths. After including estimates of inner-shell cross sections, the degradation of electrons in Ar is considered. Calculations of the final populations for each excited state are given as a function of incident energy and when applied to ionization, results in electron volts per ion pair values near 29 eV. Inner shells in our work appear to contribute by adding on the order of 5% to the loss function at energies above a kilovolt.