Monte Carlo Simulation-Based Investigation of Epoxy/Dysprosium Composites for X-ray and Gamma-ray Shielding Across Medicine Energy Ranges

Introduction and Objectives: Ionizing radiation protection is essential for minimizing the harmful effects of radiation exposure. While lead has traditionally been used as a shielding material due to its high density, its toxicity and physical limitations have driven the search for safer alternatives. This study investigates the gamma-ray attenuation properties of polymer composites containing non-toxic additives, focusing on their performance in the energy range of 15 keV to 10 MeV.Methods and Materials: Using the Geant4 simulation toolkit, the shielding efficiency of polymer composites incorporating yttrium oxide, dysprosium oxide, and zirconium dioxide was analyzed in varying concentrations. The attenuation rates and gamma-ray transmission properties of these composites were systematically evaluated.Results: The attenuation rate (intensity fraction decrease) drops uniformly with thickness, but remains consistently highest for Epoxy-5 and lowest for Epoxy-1. Below 0.5 MeV, performance is atomic number-dependent (photoelectric effect), but above this energy, all samples converge due to Compton scattering dominance. At 0.662 MeV, the average energy transferred to secondary electrons exceeds 290 keV, a value consistent across all composites, proving energy deposition is material independent.Conclusion: Additive composition critically boosts shielding by increasing interaction probability, especially below 0.5 MeV. Epoxy-5 is superior for broad-spectrum attenuation, while Epoxy-1 is an effective, lightweight solution for shielding high-energy photons (>0.5 MeV) where Compton scattering minimizes the advantage of high-Z fillers.