First-principles simulation of radiation shielding performance in TaS2–HDPE composites using Geant4

High atomic number (Z) fillers in polymer matrices provide lightweight alternatives to conventional radiation shielding. Previous studies have examined fillers such as CdO, \(WO_3\) , and \(Bi_2O_3\) . However, no prior work has investigated tantalum disulfide ( \(TaS_2\) ) in polymer composites for gamma-ray shielding, leaving a clear gap in the literature. Here, we report the photon attenuation performance of high-density polyethylene (HDPE) composites containing 10–50 wt% \(TaS_2\) over 0.06–2.0 MeV, evaluated by Geant4 Monte Carlo simulations and validated with XCOM data. At 80 keV, where enhancement is most pronounced, the 50 wt% composite achieved a mass attenuation coefficient of 2.88 ± 0.04 \(cm^2\) /g, corresponding to a 15.9 ± 0.21 improvement over pure HDPE. Composites with 35, 20, and 10 wt% \(TaS_2\) showed enhancements of 11.55 ± 0.05, 7.07 ± 0.03, and 4.04 ± 0.02 times, respectively. Benchmarking against micro-CdO–HDPE confirmed competitive or superior attenuation across the photon spectrum. These results establish TaS 2 –HDPE as a tunable, non-toxic, and effective candidate for next-generation radiation shielding applications.