Measurements of K-shell ionization cross-sections of S, Ca and Zn by 7–30 keV electron impact

The absolute K-shell ionization cross-sections of S, Ca and Zn by 7–30 keV electron impact have been measured. The targets were prepared by evaporating the compounds ZnS and CaF2 to the thick pure carbon substrates. The effects of multiple scattering of electrons penetrating the target films, electrons reflected from the thick pure carbon substrates and Bremsstrahlung photons produced when incident electrons impacted on the targets are corrected by using Monte Carlo method. The uncertainties of our measured K-shell ionization cross-sections are, respectively, ∼13% for S, ∼15% for Ca and ∼12% for Zn. The experimental results were compared with some theoretical results and available experimental data from the literature. The experimental data for S K-shell ionization cross-sections by 7–30 keV electron impact are given here for the first time.