B₂O₃–Bi₂O₃–TeO₂–BaO and TeO₂–Bi₂O₃–BaO glass systems: a comparative assessment of gamma-ray and fast and thermal neutron attenuation aspects

For Pb-free 35B₂O₃‒35Bi₂O₃‒(30–x)TeO₂‒(x)BaO (x = 5, 10, 15, 20, and 25 mol%) and (90–x)TeO₂‒10Bi₂O₃‒(x)BaO (x = 10, 15, and 20 mol%) glass systems, gamma and neutron (both fast and thermal neutron) radiation shielding features were examined and compared. Within 0.015–15 MeV photon energy, mass attenuation coefficients (μ/ρ), for all samples, which have been assessed using WinXCOM program are in fair agreement with deduced MCNP5 simulation code μ/ρ results. For all selected samples, at the lowest energy, μ/ρ has bigger values whereas at higher energy regions possess lower values. Furthermore, by employing μ/ρ values, effective atomic number (Z_eff), effective electron density (N_eff), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP) are figured out for both glass systems. For studied samples, with the gradual replacement of TeO₂ content with BaO, the derived values of Z_eff, HVL, TVL, and MFP revealed improved γ-ray shielding potentiality. Besides, within photon energy range of 0.015–15 MeV, exposure build-up factors (EBFs) and energy absorption build-up factors (EABFs) were estimated for all samples by utilizing G‒P fitting method as a function of different penetration depths (0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, 25, 30, 35, and 40 mfp). The 35B₂O₃–35Bi₂O₃–5TeO₂–25BaO (mol%) glass relatively larger μ/ρ and Z_eff values, lower HVL, TVL, and MFP values, and minimal EBF and EABF values confirm its superior γ-ray attenuation competence among all samples. Additionally, in comparison, HVL and MFP values of 35B₂O₃–35Bi₂O₃–5TeO₂–25BaO (mol%) sample are lower than the respective values of some commercial γ-ray shielding glasses and different types of standard concretes, signifying its better shielding features than them. Moreover, macroscopic removal cross-section for fast neutrons (Σ_R), coherent scattering cross-section (σ_cs), incoherent scattering cross-section (σ_ics), absorption cross-section (σ_A), and total cross-section (σ_T) for thermal neutrons absorption were derived for both glass systems. Among all selected glasses, 35B₂O₃–35Bi₂O₃–5TeO₂–25BaO (mol%) sample possesses relatively higher Σ_R (0.106 cm⁻¹) and ‘σ_T’ (8.809 cm⁻¹ at 0.0253 eV neutron energy) values for fast and thermal neutrons attenuation, respectively, demonstrating its favorable absorption capability for neutrons.