Measurement of L alpha/Ll, L alpha/L beta and L alpha/L gamma X-ray intensity ratios for elements in the atomic range 57 <= Z <= 92 using radioisotope X-ray fluorescence

L alpha /Ll, L alpha /L beta and L alpha /L gamma intensity ratios have bee n measured for some elements with atomic range 57 less than or equal to Z l ess than or equal to 92 by using characteristic L X-rays from targets excit ed by 59.54 keV photons from a filtered radioisotope Am-241 point source. T heoretical values of the L alpha /Ll, L alpha /L beta and L alpha /L gamma intensity ratios were calculated using theoretically tabulated values of su bshell photoionization cross-sections, fluorescence yields, fractional X-ra y emission rates, Coster-Kronig transition probabilities. Experimental resu lts have been compared with the theoretical values and other available expe rimental results. Good agreement was observed between experimental results, other available experimental results and theoretically calculated values. (C) 2001 Elsevier Science B.V. All rights reserved.