Enhanced gamma and neutron shielding performance of silicon-tungsten composites: A Geant4 simulation study

The development of effective radiation shielding materials is crucial for minimizing the harmful effects of ionizing radiation on human health and the environment. This study investigates the gamma-ray and neutron shielding performance of silicon-tungsten composites with varying tungsten concentrations (0 %, 30.1 %, 47.8 %, 58.8 %, 68.1 %, and 88 %) across a gamma energy range of 59 keV–2000 keV. The methodology employs Geant4 simulations, utilizing a point photon source and a NaI detector to measure un-attenuated photons, alongside EpiXS for validation of key shielding parameters. Critical parameters, including half-value layers, mass attenuation coefficients (μ/ρ), linear attenuation coefficients (μ), fast neutron removal cross-sections, and effective atomic numbers (Z_eff), were evaluated to assess the shielding effectiveness of the composites against both gamma rays and neutrons. Additionally, a Geant4-designed female phantom was used to simulate real-world shielding scenarios, with a gamma source positioned near the chest and cylindrical shielding placed around the torso. Results indicate a significant improvement in shielding performance with increasing tungsten content, with the 88 % tungsten, Silicon-Tungsten 5 composite demonstrating the highest dose absorption and scattering efficiency. These findings underscore the potential of silicon-tungsten composites as effective radiation shielding materials for applications such as protective gloves and apparel, addressing occupational exposure in medical, industrial, and nuclear sectors.