Photon shielding response of GNP-reinforced B4C-TiB2 composites: Experimental and MCNP6.2 insights

Abstract

In this study, the gamma and X-ray radiation attenuation properties of B4C-TiB2 reference ceramics and those reinforced with 1, 2, and 3 vol% graphene nanoplatelets (GNP) were systematically investigated. The composites were fabricated via Spark Plasma Sintering (SPS), enabling rapid densification and controlled microstructural evolution. B4C is known for its strong thermal neutron absorption due to its high 10B content. In addition, it contributes to gamma radiation attenuation through photon absorption and scattering interactions. The incorporation of TiB2 and GNPs into B4C enhances the composite density thereby increasing the photon interaction probability and improving the overall gamma shielding performance. Radiation attenuation measurements of the composites were conducted using 0.356 MeV (133Ba), 0.662 MeV (137Cs), and 1.173 MeV (60Co) sources, and diagnostic X-ray sources (50-110 kVp). Gamma and X-ray attenuation coefficients were independently calculated through MCNP6.2 Monte Carlo simulations to validate the experimental results. The close agreement between simulated and measured values demonstrates the reliability of the computational methodology and its consistency with established theoretical models of photon interaction cross sections. This consistency further supports the applicability of the approach for accurate evaluation and comparative analysis of photon attenuation performance in composite materials. In this study, key photon interaction parameters including the half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff), and effective electron density (Neff) were computed. The results indicate that these parameters are significantly dependent on both the photon energy and the chemical composition of the examined composites. Both MCNP and experimental results show that the B4C-TiB2-GNP composites have linear attenuation coefficients (mu) ranging from 0.1468 to 0.2498 cm-1, with the sample with 1 vol% GNP (BT1G) exhibits the highest performance, reaching 0.2498 cm-1 for 133Ba. The results reveal that among all investigated samples, the BT1G composite exhibits the highest shielding efficiency in radiation conditions. GNP-reinforced B4C-TiB2 composites, may serve as a potential alternative to reduce the use of lead in gamma radiation protection.