Neutron and γ-ray shielding properties of magnetite-serpentine concrete based on Geant4 simulation

Serpentine concrete is an excellent neutron shielding material, and the addition of magnetite aggregate can enhance the γ-ray shielding performance of concrete. In this study, the Geant4 software was used to simulate and analyze five different concrete mix designs where magnetite aggregate replaced serpentine aggregate at varying concentrations. To ensure the reliability of the simulation results, the study compared them with the calculated data obtained from the Phy-X/PSD program. For both neutrons and γ-rays, several shielding parameters including linear attenuation coefficient ( μ ), half-value layer (HVL) and effective atomic number ( Z eff ) as well as effective electron density ( N eff ) were systematically calculated. Penetration rate and neutron energy spectrum analyses were also conducted. The results show that with the increase of magnetite doping, the γ-ray shielding performance of concrete is significantly enhanced, but the neutron shielding ability decreases. Based on a comprehensive evaluation of various performance indicators, the optimal proportion of magnetite aggregate was determined to be 25 %. The neutron shielding performance of this admixture is similar to that of pure serpentine concrete, while its γ-ray shielding performance is significantly improved.