Systematic measurements of M X‐ray components X‐ray fluorescence cross‐sections for the elements with 77 ≤ Z ≤ 92 by employing laboratory source based energy dispersive X‐ray fluorescence setup

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AbstractThe differential X‐ray fluorescence (XRF) cross‐sections for (Mξ2, Mξ1, Mδ1), (Mδ2, Mα1,2 M5‐O3), (Mβ, M4‐O2,3), (Mγ, Mm2, M3‐N4, M5‐O2,3), (Mm1, M3‐N6,7, M3‐O4,5) and (Mm2, M2‐N6) group of M X‐rays components have been measured for the elements with 77 ≤ Z ≤ 92 following photoionization by Mn K X‐rays (EKαβ = 5.96 keV) obtained from 55Fe radioisotope. The measurements were performed in annular source geometry at 126° emission angle using a low‐energy Ge (LEGe) detector. The measured cross‐section values are compared with theoretical values calculated using available sets of Mi (i = 1–5) photoionization cross‐sections, radiative emission rates (Fij), Coster‐Kronig (fij), and fluorescence (ωi) yields. The measured XRF cross‐sections for the (Mξ2, Mξ1, Mδ1), (Mm1, M3‐N6,7) and (Mm2, M2‐N6) groups of X‐rays agree with the theoretical values within the experimental errors. The (Mβ, M4‐O2,3) group of X‐rays exhibit agreement with theoretical values within experimental uncertainty for all the elements under investigation except 79Au and 80Hg. The XRF cross‐section for the (Mδ2, Mα1,2) group of X‐rays are in general higher by ~20% for the elements with Z = 77–83 and exhibit agreement for the 90Th and 92U elements. For the (Mγ, Mm2, M3‐N4) X‐ray group, the measured values are generally higher than the theoretical values, but the deviations are within experimental uncertainties. The large deviation in measured XRF cross‐section for different M X‐ray components from the theoretical ones are attributed to (i) poor separation of M X‐ray components (ii) contribution of self‐resonant Raman scattering (RRS) process and (iii) self‐fluorescence of M5 subshell by Mi subshell X‐rays (i = 1–3).