Asymptotic expression for K-shell ionization cross section with electrons

Abstract

The total cross section for K‐shell ionization with electrons as given is a function of the K‐shell screening parameter ϑ for target elements with Z≳13 and incident electron energies much higher than the K‐shell binding energy. For an incident electron energy of 300 MeV, the cross section varies with the atomic number approximately as Z^−2.55 compared to the experimental result Z^−2.69.