Rayleigh scattering of 16.58 keV photons in the atomic region 59 ≤ Z ≤ 82 at q = 0.9457 h A-1

Coherent scattering cross sections for the elements Pr, Sm, Gd, Dy, Ho, Er Pt, Au and Pb have been measured at the excitation energy 16.58 keV. The measured cross sections are compared with the normalised integrated scattering cross section values calculated using relativistic, non-relativistic and relativistic modified form factors. Atomic form factors are extracted from the measured cross sections at q = 0.9457 h A-1. The results were compared with the different formalisms of form factor theory and their validity at q = 0.9457 h A-1 is thoroughly discussed. (orig.)