Fast neutron shielding performance of polyethylene–titanium diboride (TiB2) composites for nuclear facilities

Neutrons are widely used in the nuclear field, but their high penetration and associated secondary radiation require effective shielding. While conventional materials such as concrete, water, pure polyethylene and borated polyethylene are commonly used, developing advanced composites with improved properties remains essential. This work investigates the neutron shielding performance of polyethylene (PE) composites reinforced with titanium diboride (TiB₂) at different weight concentrations (10, 20, and 30 wt%). Monte Carlo simulations were performed using the GEANT4 toolkit to evaluate the neutron transmission through varying thicknesses (1–5 cm) of the proposed materials when exposed to two neutron sources, 241Am-Be and 252Cf. The results indicate that neutrons from 252Cf are more effectively attenuated by the PE–TiB₂ composites compared to those from 241Am-Be. Neutron removal cross sections were also calculated based on ENDF/B-VIII.0 nuclear data and GEANT4. A good agreement between GEANT4 simulations and ENDF/B-VIII.0 data was observed, confirming the reliability of the adopted computational approach. The results indicate that neutron attenuation increases with TiB₂ content, with PE–30TiB₂ showing competitive performance compared to reference materials at 4.5 MeV. These findings demonstrate the potential of PE–TiB₂ composites as effective lightweight materials for fast neutron shielding applications.