Small angle elastic scattering of 122 and 245 keV γ-rays

The elastic scattering of 122 and 245 keV γ-rays from a source containing 152Eu and 154Eu has been measured for scattering through 5deg, 7deg and 10deg by targets of Al, Cu, Mo, Sn, Ta and Pb. The experimental cross sections have been normalized to theoretical cross sections for carbon. The results for 245 keV γ-rays have been obtained using a least-squares fit of the overlapping elastic and Compton peaks, whereas the results for 122 keV γ-rays have been obtained by a subtraction method using theoretical Compton cross sections. The experimental elastic cross sections are in very good agreement (to better than 5%) with the theoretical calculations of Kane et al. ]Phys. Rep. 140 (1986) 75[ and provide strong support for the calculational scheme of Kissell and Pratt ]Phys. Rev. A22 (1980) 1970[ for the evaluation of total atom Rayleigh scattering in the regime where there are significant contributions from outer electron shells