Measurement of cross-sections and Coster-Kronig transition effect on L subshell X-rays of some heavy elements in the atomic range 79 <= Z <= 92 at 59.5 keV
L l, L α, L β and L γ X-ray production cross sections have been measured in the atomic range 79≤ Z≤92 at 59.5 keV by measuring differential cross-sections. The experimental values of the cross-sections were determined by measuring the absolute yield of L subshell X-rays emitted from a target of a given element and thickness when it was bombarded with a known flux of photons of given energy. The theoretical values of the cross-sections were calculated from the theoretical values of subshell photoionization cross-sections, fluorescence yields, Coster-Kronig transition probabilities and radiative decay rates. The enhancement effect of Coster-Kronig transition have been calculated of these elements at same energy. Coster-Kronig processes are radionless 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 to Coster-Kronig transitions on fluorescence cross-sections for the L subshell X-ray lines using 59.5 keV for excitation. Absolute values of the L subshell X-ray cross-sections were also calculated with incorporation of the enhancement due to the Coster-Kronig effect for the elements in the range 79≤ Z≤92 at the same excitation energy. The present results are compared with the other experimental and theoretical values.