Flexible WO ₃ –polymer shields for diagnostic X-ray energies: Monte Carlo modeling of attenuation parameters

Purpose There is a growing demand for lightweight and flexible alternatives to traditional lead-based radiation shields. This trend is driving interest in high atomic number (high-Z) nanoparticle–reinforced polymer composites. This study examines the photon attenuation of polyvinyl alcohol/polyethylene glycol (PVA/PEG) matrices containing tungsten trioxide (WO3; 0–40% v/v). These composites are tested across the diagnostic X-ray energy range of 20–150 kiloelectronvolts (keV).Materials and Methods Five PVA/PEG–WO3 composites were modeled in the GAMOS 6.2.0 Monte Carlo framework. The mass attenuation coefficient (MAC) was derived from transmitted fluence under monoenergetic, narrow-beam irradiation. From the simulated data, for each energy and composition, the following were calculated: the linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP).Results Attenuation improved with increasing tungsten trioxide (WO3) content. The 40% v/v composite exhibited the strongest performance at low energies, where photoelectric interactions are dominant. HVL decreased markedly compared to the undoped matrix, reaching sub-centimeter values over the 20–60 keV interval. MFP displayed similar reductions. This suggests an increased probability of photon interaction in WO3-rich formulations.Conclusion The attenuation trends predicted in this study are fully consistent with previously reported Monte Carlo and experimental investigations on tungsten-based flexible shielding materials, confirming the suitability of the GAMOS-based approach for evaluating and optimizing lead-free polymer composites in the diagnostic X-ray energy range.