MEASUREMENT OF CROSS-SECTIONS AND COSTER-KRONIG TRANSITION EFFECT ON L-SUBSHELL X-RAYS OF SOME HEAVY-ELEMENTS IN THE ATOMIC RANGE 9-LESS-THAN-OR-EQUAL-TO-Z-LESS-THAN-OR-EQUAL-TO-92 AT 59.5 KEV

L(l), L(alpha), L(beta) and L(gamma) X-ray production cross sections h ave been measured in the atomic range 79 less than or equal to Z less than or equal to 92 at 59.5 keV by measuring differential cross-sectio ns. The experimental values of the cross-sections were determined by m easuring 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 f lux of photons of given energy. The theoretical values of the cross-se ctions were calculated from the theoretical values of subshell photoio nization cross-sections, fluorescence yields, Coster-Kronig transition probabilities and radiative decay rates. The enhancement effect of Co ster-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 an other 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 fluoresc ence 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 wer e also calculated with incorporation of the enhancement due to the Cos ter-Kronig effect for the elements in the range 79 less than or equal to Z less than or equal to 92 at the same excitation energy. The prese nt results are compared with the other experimental and theoretical va lues.