Effect of coster–kronig transitions on L3 sub-shell x-ray fluorescence cross-sections

Coster–Kronig processes are radiationless transitions in which an inner-shell vacancy is transferred from one subshell of an atom to another that is less tightly bound, both belonging to the same principal shell. Experimental measurements were carried out on a few elemental samples to examine the effect of Coster–Kronig transitions on fluorescence cross-sections for the Lα x-ray line using 22.6 keV Ag K x-rays for excitation. Absolute values of Lα cross-sections were also calculated with incorporation of the enhancement due to the Coster–Kronig effect for the elements in the range 41 ≤ Z ≤ 92 at the same excitation energy. A windowless Si(Li) detector system with an energy resolution of 145 eV at 6.4 keV x-ray energy was used. Thin-film samples were employed to minimize the self-absorption effect. Reasonably good agreement was observed between the expected and measured values.