Differential cross-section measurements for elastic and inelastic scattering of 17.44 keV photons

Differential cross-sections for the elastic and inelastic scattering of the 17.44 keV photons (Mo Kα X-rays) have been measured at an angle of 141° for the elements in the atomic regions 6 ⩽ Z ⩽ 90 and 1 ⩽ Z ⩽ 50, respectively. The measurements were performed in vacuo using reflection mode geometrical set-up involving a secondary photon source consisting of an annular Mo-foil excited by the 59.54 keV γ-rays from an 241Am radioactive source and a planar HPGe/Si(Li) detector. Intensity of the incident photons, detector efficiency and other geometrical factors were determined by measuring K X-ray yields from targets with 32 ⩽ Z ⩽ 42 and from knowledge of the corresponding cross-sections. The incident and emission angles, used in evaluation of the absorption correction for the photons in the target, were deduced using computer simulations. The measured elastic and inelastic scattering cross-sections for all the elements under investigation are closely represented by the second-order S-matrix calculations and the Klein–Nishina cross-sections incorporating the incoherent scattering function, respectively.