CORRECTION OF SUBSTRATE EFFECT IN THE MEASUREMENT OF 8-25-KEV ELECTRON-IMPACT K-SHELL IONIZATION CROSS-SECTIONS OF CU AND CO ELEMENTS

The experimental measurement of electron-impact K-shell ionization cro ss sections of Cu and Co elements within the energy region 8-25 keV wa s reported. The influence of a substrate of thin targets on ionization cross sections has been corrected by a method based upon a bipartitio n model of electron transport [Z. M. Luo, Phys. Rev. B 32, 812 (1985); 32, 824 (1985)]. The measured cross sections are in good agreement wi th existing data and are well reproduced by the empirical formula of G reen and Cosslett [Proc. Phys. Sec. London 78, 1206 (1961)].