Measurements have been made of the relative X-ray .production cross-section ratios L./Ly, L./Lp and L./Ll using electrons of energy from 20 to 100 keV incident on thin targets of tin and gadolinium. The experimental ratios obtained are compared with theoretical values. Modification of these ratios due to the formation of double-vacancy atomic states has been calculated, but this effect on its own is not sufficient to account for the discrepancy between the L./Ll theoretical and experimental results for tin.
L-shell Ionization of Sn and Gd by 20?100 keV Electron Impact