Evaluation of polymer composites for protection against gamma and neutron irradiation

This study demonstrates that Epoxy-5 delivers superior dual-mode shielding against both gamma rays and neutrons, validated by results Geant4 simulations and Phy-X/PSD theory (with excellent agreement). For gamma radiation, Epoxy-5 achieves the highest linear attenuation coefficient, lowest tenth-value layer, and the lowest radiation transmission factor, especially at low energies (< 100 keV), where Eu₂O₃ is the key contributor due to its high atomic number and strong photoelectric absorption. Yb₂O₃ mainly enhances density and supports pair production at higher energies. For neutron shielding, Epoxy-5 shows the highest fast neutron removal cross-section and best attenuation (up to 68% at 3 cm), thanks to hydrogen in the epoxy (for moderation) and europium (for capture and inelastic scattering). It also has the highest thermal neutron total and absorption cross-sections, directly linked to europium’s large neutron capture probability. Critically, optimal performance requires the synergistic combination of both Eu₂O₃ and Yb₂O₃. This balance makes Epoxy-5 a lightweight, non-toxic, multifunctional shield ideal for mixed-field radiation environments in medical, nuclear, and portable protection applications.