Measurements of whole-atom coherent and incoherent scattering cross-sections in some rare earth elements at low photon energies

Differential coherent atomic scattering cross-sections and incoherent scattering functions were experimentally determined for photon energies 145 and 320 keV in the angular range 40-100o in the elements Gd, Dy, Er and Yb with the use of the aluminium difference technique. The experimental values have been compared with the data compiled by Hubbell et al. A comparison with the data of Hubbell et al. reveals a good correspondence between theory and experiment for the non-relativistic incoherent scattering function but not for the non-relativistic atomic form factor (coherent scattering). (author)