With the advancement of fabrication technology, composite materials that consist of isotopes with different radiation interaction properties can be manufactured and used as effective radiation shielding materials. This work details an investigation into the contributing factors behind the success of newly developed composite shielding materials. Monte Carlo simulation methods were utilized to assess the shielding capabilities for neutron and the secondary radiation production characteristics in four different composite materials: aluminum boron carbide, tungsten boron carbide, bismuth borosilicate glass, and Metathene. The study is performed under neutron irradiations with various energy spectra. The resulting data regarding shielding performance and generated secondary radiation suggested that tungsten boron carbide was the most effective composite shield material. An analysis of the macroscopic cross-section contributions from constituent materials and interaction mechanisms was then performed in an attempt to better understand the relative shielding performance of the investigated composite materials. This analysis found that increased thermal absorber content was associated with improved neutron shielding performance within both the thermal and epi-thermal neutron energy regions and that composites containing low Z material demonstrated greater shielding performance within the faster neutron energy regions.
