Comparison of the measured and the calculated total thermal neutron cross-section of Pb

Lead is one of the materials commonly used in the design of neutron sources. However, with the increased accuracy expectations of the predictions for these sources it is no longer prudent to represent the neutron cross-section of lead in the thermal regime by the free gas model. We have therefore generated a scattering kernel for lead for which we have replaced the ideal gas approximation by a generalized crystallographic model, which includes the crystal structure of lead and the inelastic scattering in terms of the phonon spectrum of the material. These theoretical results then were compared to measurements.