Experimental evidence for onset of L1–L3M5 transition at Z = 75 through measurements of fluorescence and Coster–Kronig yields for W and Re

In the present work, the experimental Li (i = 1–3) sub-shell fluorescence (ω1, ω2, ω3) and Coster–Kronig (f12, f13, f23) yields for W and Re have been deduced from synchrotron radiation induced X-ray line intensities measured at different incident energies across the Li absorption edge energies of both the elements employing two sets of photoionization cross sections based on the non-relativistic Hartree–Fock–Slater model and the self-consistent Dirac–Hartree–Fock model. These deduced yields have been compared with the Dirac–Hartree–Slater model based theoretical values, the semi-empirical values tabulated by Krause and the recommended values tabulated by Campbell. The present investigation provided reliable experimental evidence indicating the onset of intense L1–L3M5 Coster–Kronig transition at Z = 75.