Selenium and yttrium K-shell ionization cross-sections by electron impact

This paper reports the experimental measurement of Se and Y K-shell ionization cross sections by electron impact. The thin targets with thick substrate are used in the experiment. The influence of the electrons reflected from the substrate on the measurements is discussed and corrected. For Se and Y, in energies from near threshold to 40 keV, the experimental data are reported and compared with the empirical formula.