Experimental and Monte Carlo evaluation of gamma-ray shielding in Bi2O3 + PbO co-modified borosilicate glasses: Insights from structural and optical properties

The current work aims to fabricate and examine a borosilicate glass series composed of (77-x-y)B 2 O 3 −15SiO 2 - 8CaO-xBi 2 O 3 -yPbO; x = 5, 7, 9, and 11 mol% and y = 5, 8, 11, and 14 mol% for optical and radiation shielding applications. The measurement of the fabricated glasses density shows an enhancement by ≈ 32.4% when the Bi 2 O 3 + PbO modifier concentration moves from 10 to 25 mol%. The investigated glasses were confirmed to be non-crystalline by XRD analysis. FT-IR assessment revealed a gradual conversion of BO 4 to BO 3 groups and increased non-bridging oxygen creation with elevating Bi 2 O 3 + PbO loading, signifying structural modification of the borate network. UV-Visible absorption analysis showed a red shift in the cutoff wavelength from 377 to 486 nm and a decline in the direct energy band gap from 3.443 to 2.953 eV. Additionally, the shielding performance for the fabricated glasses was examined experimentally using the NaI (Tl) detector over an energy interval that fluctuated from 0.356 to 1.332 MeV. The measured linear attenuation coefficient (LAC) was enhanced by ≈ 28.7% from 0.331 cm −1 to 0.426 cm −1 as the Bi 2 O 3 + PbO concentration rises from 10 to 25 mol%, respectively. The measured LACs were confirmed using the Monte Carlo simulation across the same mentioned γ-ray energy interval. Acceptable differences were observed between the experimental and simulated LACs. The rise in LAC with elevating Bi 2 O 3 + PbO concentration results in higher Pb-equivalent thickness and radiation protection efficiency, together with declined half-value thickness, signifying the promising capacity of the examined glasses, specifically Bi11Pb14, for advanced gamma-ray protection applications.