Experimental and simulation study of shielding features of polyester/HgO composites against photons using GEANT4 and MCNP codes

In this study, the shielding properties of six samples of the polyester (PE)/HgO composite against photons with an energy range of 0.01-15 MeV (including a ¹³⁷Cs source with an energy of 662 keV) are evaluated. Moreover, to study the structure of the samples, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed. The experimental results of the linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Z_eff), effective electron density (N_eff), and equivalent atomic number (Z_eq) parameters were compared to the simulation values obtained by the Monte Carlo codes GEANT4 and MCNP and the online programs Phy-X/photon shielding and dosimetry (PSD) and XCOM. The experimental data and simulation values exhibited good compatibility. The experimental result and simulated values (by GEANT4, MCNP, Phy-X/PSD, and XCOM programs) of the MAC parameter for the Hg5 sample are 0.0843 ± 0.002, 0.0843, 0.0833, 0.0845, and 0.0840 cm²/g, respectively. Therefore, the Hg5 sample with the highest value of density and MAC can be selected as the best shield against photons with an energy of 662 keV among the other samples.