High-density polyethylene composites reinforced with metal oxides and carbides for enhanced gamma-ray shielding and balanced neutron attenuation: a comparative study

This study investigated the potential of high-density polyethylene (HDPE) composites reinforced with various metal oxides and carbides for γ-ray shielding applications. Titanium dioxide (TiO₂), molybdenum carbide (MoC), tungsten carbide (WC), and ferric oxide (Fe₂O₃) were incorporated as fillers into the HDPE matrix. The effectiveness of these composites (HDPE/TiO₂, HDPE/MoC, HDPE/WC, and HDPE/Fe₂O₃) in attenuating γ-rays was evaluated using a tunable-energy X-ray source (40.9–79.7 keV). Radiation intensities were precisely measured using an ionization chamber detector. The inclusion of metal carbide fillers, particularly MoC and WC, significantly enhanced the γ-ray shielding performance compared to pure HDPE. This improvement can be attributed to their high density and atomic numbers, which contributed to better γ-ray attenuation, as reflected in the increased attenuation coefficients, effective atomic numbers, and γ-ray kerma coefficients, as well as higher radiation protection efficiency (RPE). The strong agreement between the measured and calculated attenuation coefficients, obtained using XCOM software, further validates these findings Additionally, the macroscopic effective removal cross section for fast neutrons (ΣR) and the macroscopic cross section for thermal neutrons (Σth) were estimated for neutron shielding analysis. While the addition of reinforcements resulted in minimal changes to ΣR, a slight decrease in Σth was observed. In conclusion, this research demonstrates the promising potential of HDPE composites containing MoC and WC additives for effective shielding against low-energy γ-rays while maintaining a high level of protection against both fast and thermal neutrons.