Small angle scattering of 59.54 keV photons by elemental samples in the atomic number region 13 ≤ Z ≤ 82

Abstract

In the present paper, we report the angle integrated coherent scattering cross sections of some elements at low momentum transfer over four angular ranges for some elements in the atomic number range 13≤Z≤82 for 241Am (59.54 keV) gamma rays. The coherent scattering cross sections were derived from the experimentally measured total (Coherent + incoherent) scattering cross sections for the elements at the energy of interest by subtracting separately the small contribution of the corresponding angle integrated incoherent scattering cross sections. The theoretical angle integrated incoherent scattering cross sections were computed by numerically integrating the values provided in the compilations based on the non-relativistic Hartree-Fock (NRHF) model and the modified form factor (MFF) model for the charge distribution within the atom. The present values of the angle integrated coherent scattering cross sections of the elements Al, Fe, Cu, Zn, Cd, Sn and Pb at 59.54 keV in the angular ranges of (0∘−4∘), (0∘−6∘), (0∘−8∘) and (0°–10°) so obtained are compared with the corresponding theoretical S-matrix data within the range of experimental errors. The root mean square error on the measured cross sections was found to be the lowest for Al at 4.1% and the highest for Pb at 4.9%. For the other elements the error was in between these two values. Possible conclusions are drawn based on the present study.

Keywords

• Low momentum transfer
• Coherent scattering
• Incoherent scattering
• Non-relativistic Hartree-Fock model
• Modified form factor model
• S-matrix values