L sub-shell fluorescence cross-section measurements for elements, Z = 62-67, at tuned photon energies

•L sub-shell XRF cross-sections for 6 elements with Z = 62-67.•Three synchrotron photon energies at 0.1 keV intervals in each region; > EL1, < EL1 & >EL2 and EL3; ELi absorption edges.•Comparison of measured cross-sections with calculated theoretical values.•fij and ωi are evaluated from measured XRF cross-sections and compared with their literature values.•From trends of total measured L XRF cross-sections with photon energy results were found affected by the 4f electron filling in the elements.

L sub-shell X-ray fluorescence (XRF) cross-sections for 6 elements with Z = 62-67 have been measured at tuned photon energies on synchrotron Beamline-16, Indus-2, RRCAT, India. Three incident photon energies at the intervals of 0.1 keV were tuned in each region; > EL1, < EL1 & >EL2 and EL3 where ELi are Li (i = 1-3) absorption edge energies of element. No single measurement is available in literature for present incident photon energies and elements, therefore, certainty and reliability of the measurements have been judged from three different aspects. One, from comparison of measured cross-sections with calculated theoretical values. Second, evaluation of Coster-Kronig yield (fij's) and fluorescence yield (ωi's) fine parameters from measured XRF cross-sections with formulations derived from total intensity of X-rays originating from individual sub-shells that generated a data set for fij's and ωi's of six elements for comparison with available theoretical/empirical/experimental values. Third, from trends of total measured L XRF cross-sections with photon energy for the elements. The results were found affected by the 4f electron filling in the elements.