Calculating the Atomic electron impact Ionization Cross Section for some elements

Abstract

Inner-shell ionization cross section (ICS) by electron impact are of interest not only to the basic collision physics for complex atoms, but also to various practical applications in material science and electron microscopy. Theoretical difficulties in the past were between the threshold and the peak, which occur usually four to five times the threshold energy. Theories based on classical mechanics are somewhat better than on Born cross section, but such theories usually requires adjustable parameters. We used the Gryzinski formalism to calculate atomic electron impact ionization cross sections for the elements (Fe, Co, Mn, Ti, Zn, and Nb). Good to satisfactory agreement was found for all atoms with the exception of (Nb), where the distance between our cross section and Deutsch-Mark formula become larger at the high values of the overvoltage (U). Moreover, when compared to other to available ionization cross sections for these atoms, calculated using other methods and semiempirical formula, the Gryzinski formalism achieved a level of agreement with experimental data that is as good better than the predictions from the other methods.