Experimental and simulation-based optimization of gamma-ray shielding using cement boards in Saudi Arabia

This study evaluates the effectiveness of commercially available cement boards in Saudi Arabia for gamma-ray shielding applications. The elemental composition of each board was identified using Energy Dispersive X-ray Spectroscopy, and their ability to attenuate gamma radiation was experimentally tested using cesium-137 (662 keV) and americium-241 (59.5 keV) sources. The results showed that the linear attenuation coefficients range from 0.0855 to 0.1110 cm⁻¹ for 662 keV gamma photons and from 0.3760 to 0.4752 cm⁻¹ for 59.5 keV gamma photons, indicating moderate shielding performance. These experimental findings closely matched the theoretical values from the NIST XCOM database and were further confirmed through GEANT4 Monte Carlo simulations. To achieve better shielding, advanced cement composites were developed by adding high atomic number oxides, including bismuth oxide, lead oxide, tungsten trioxide, barium sulfate, and copper oxide. Simulation results revealed significant improvements in shielding efficiency, particularly at lower photon energies, where the photoelectric effect is dominant. Among these enhanced composites, the mixture containing lead oxide and bismuth oxide exhibited the highest performance, achieving a linear attenuation coefficient of 2.42 cm⁻¹ at 59.5 keV. These findings demonstrate that lead-free optimized cementitious materials can serve as effective, environmentally safer, and structurally viable alternatives to radiation shielding in medical, nuclear, and industrial applications.