Measurement of angular distribution of fluorescent X-rays and L subshell fluorescence yields in thorium and uranium

Abstract

Lℓ,L α,L β 2,4,L β 1,3 and L γ X-ray production cross-sections and L-subshell fluorescence yields ( ω 1 and ω 2) in Th and U have been determined at an incident photon energy of 59.5 keV by measuring differential cross-sections with angles changing at intervals of 10° from 40° to 130°. In particular, we have investigated the angular dependence of production cross-sections for the L β 2,4 and L β 1,3 lines which can be obtained with some ease for U and Th in Si(Li) detector. The experimental values of cross-sections were obtained by using the absolute yield of L subshell X-rays emitted from a target of a given element and thickness when bombarded with a known flux of photons of given energy. The theoretical values of the cross-sections were estimated from the theoretical values of subshell photoionization cross-sections, fluorescence yields, Coster–Kronig transition probabilities and relative decay rates. The enhancement effect of the Coster–Kronig transition have been calculated for these elements at the same photon energy. The present experimental results have been compared with theoretical and other experimental values. It has been found that the present experimental results are in good agreement with theoretical and the experimental values of others.