Measurement of L X-ray cross-sections and relative intensities of heavy elements by 15.2Â keV photons

Total L X-ray fluorescence cross-sections have been measured for the elements La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb and Lu using a photon energy of 15.2 keV. The measurements have been performed using an annular source of 241Am. The obtained cross-sections were then compared with the theoretical values evaluated using semi-empirically fitted values of L-subshell fluorescence yields and Coster-Kronig transition probabilities based on relativistic Dirac-Hartree-Slater theory. Good agreement was observed between the experimental and theoretical values. Relative intensities ILβ/ILα and ILγ/ILα have been also measured for the same elements. The accuracy of the measurements varies up to 6% (except for the Lγ X-ray line around 8%).