iron and S+S concrete albedos for thermal neutrons

The aim of the sphere experiments is to evaluate the albedos of materials used in the protection of piles for neutrons of various energies. Up to now, these experiments have been carried out to estimate the albedo for thermal neutrons of S + S concrete in great thickness, as well as a 2 cm layer of iron blade against the previous concrete. The aim of the present study is to relate these experiments to the monoenergetic albedo calculation formalisms currently in use, by making appropriate adjustments to the effective cross-sections, the estimation of which is often affected by uncertainties, particularly in composite materials. After reviewing the results of scattering experiments inside a sphere, the authors describe the formalisms adopted for calculating albedos in thermal neutrons. The experimental results are compared with albedo calculations for 1) S+S concrete for thermal neutrons; and 2) iron plate