Monte Carlo study of CdO effects on borate glass shielding performance

Potassium-barium borate glasses with varying cadmium oxide contents were synthesized using the conventional melt-quenching technique. Structural characterization revealed that all samples were fully amorphous, as confirmed by X-ray diffraction through the absence of crystalline peaks. With increasing CdO concentration, the glass density increased while the molar volume slightly decreased, indicating enhanced network compactness. Gamma-ray shielding performance was evaluated using Monte Carlo simulations (MCNPX) to determine the mass attenuation coefficients (μ_m) over an energy range of 0.015-15 MeV. Four glass compositions (S1-S4) were investigated. The μ_m values obtained from MCNPX were validated against calculations from Phy-X/PSD, and the relative deviation (RD) between the two methods was found to be less than 1.025%. The MCNPX simulations were performed with a sufficient number of particle histories to maintain a relative statistical error of less than 2%, confirming that the observed deviations fall within the statistical uncertainty limits of the Monte Carlo calculations. Additional shielding parameters, including the half-value layer (HVL), mean free path (MFP), effective electron density (Neff), and effective atomic number (Zeff), were also evaluated. The results demonstrate that increasing CdO content progressively enhances the gamma-ray shielding efficiency of the glass system. An optimal CdO concentration of approximately 13 wt% for S4 was identified for sample S4, exhibiting effective gamma attenuation. These findings confirm the potential of the developed glass compositions as efficient radioprotective materials, providing a valuable reference for future radiation-shielding applications.