L-i, L-x, L-eta, L-beta and L-gamma X-ray fluorescence cross-sections have been measured for the elements Yb, Lu, W, Hg, Tl, Pb, Bi and U using excitation energy of 59.543 keV. Measurements have been performed using an Am-241 annular source and a Si(Li) detector. The experimental values of the cross-sections were determined by measuring the absolute yield of L subshell X-rays emitted from a standard target of a given element irradiated with photons of given energy. The theoretical values of the cross-sections were calculated using theoretically tabulated values of subshellphotoionization cross-sections, fluorescence yields, Coster-Kronig transition probabilities and radiative decay rates. Experimental results have been compared with the theoretically calculated values of L X-ray cross-sections. A fairly good agreement is obtained between the experimental and the calculated values. (C) 2001 Elsevier Science Ltd. All rights reserved.