Measurements of X-ray production cross sections at photon energies across the Li (i = 1-3) sub-shell absorption edges of 74W and 76Os using synchrotron radiation

The cross sections for production of the Lk (k = l, η, α, β1,3,4,6, β2,15,5,7, γ1,5, γ2,3) X-rays have been measured at different incident photon energies ranging 10.2-13.1 keV across the Li (i = 1-3) sub-shell absorption edge energies of 74W and 76Os. These measured XRP cross sections, σLk(exp), exhibited significant differences with two sets of the theoretical values calculated using the Dirac-Fock (DF) model based X-ray emission rates provided by Campbell and Wang (1989), Dirac-Hartree-Slater (DHS) model based fluorescence (ωi) and Coster-Kronig (fij) yields given by Puri et al. (1993) and two sets of the Li (i = 1-3) sub-shell photoionization cross sections based on the non-relativistic Hartree-Fock-Slater (HFS) model tabulated by Scofield (1973) and those deduced from the self-consistent Dirac-Hartree-Fock (DHF) model based theoretical total photoionization attenuation coefficients tabulated by Chantler (1995). However, the branching ratios (ILk/ILα)exp (k = l, β2,15) and(ILk/ILβ1)exp (k = γ1,5, η) are found to agree with the theoretical values.