The effect of barite proportion on neutron and gamma-ray shielding

The neutron and gamma-ray shielding properties of concrete containing different proportions of barite as an aggregate have been investigated. The macroscopic fast neutron removal cross-sections have been calculated and compared with the attenuation of gamma-rays with 8 MeV photon energy, because for most shields the neutron produced at 8 MeV are most likely to penetrate. The calculation of neutron removal cross-section has been done by using NXcom program and the photon linear attenuation coefficients were obtained via XCOM code. The best values of barite proportion and density of concrete for maximum shielding against both neutrons and gamma-rays have been determined graphically. The transmission of both gamma rays and neutrons has been obtained as a function of thickness of concrete for all concrete types. It was found that increasing barite proportion in the concrete increased the gamma attenuation coefficient while it decreased the neutron removal cross-section. (C) 2012 Elsevier Ltd. All rights reserved.