Angular dependence of L x-ray production cross-section in seven elements from Au to U at 59.5 keV photon energy

The Ll, Lα, Lβ and Lγ x‐ray production cross‐sections in U, Th, Bi, Pb, Tl, Hg and Au were measured using 59.5 keV incident photon energies in the angular range 40–130°. The measurements were performed using the 241Am radioisotope as photon source and a detection system with an Si(Li) detector. Although differential cross‐sections for Lβ and Lγ x‐rays were found to be angle independent, within experimental error, those for Ll and Lα x‐rays were found to be angle dependent. This confirms the angular dependence of measured photon induced Ll and Lα x‐ray production cross‐sections as reported by two groups. Further, the present results also confirm the theoretical predictions of two other groups but are contrary to the results reported by others. Integral cross‐sections for production of Ll, Lα, Lβ and Lγ x‐rays were also deduced and were found to be in good agreement with the theoretical values. Copyright © 2002 John Wiley & Sons, Ltd.