Estimation of gamma-rays, and fast and the thermal neutrons attenuation characteristics for bismuth tellurite and bismuth boro-tellurite glass systems

Gamma-rays and fast and thermal neutron attenuation features of (Bi₂O₃)_x–(TeO₂)_(100−x) (where x = 5, 8, 10, 12, and 15 mol%) and [(TeO₂)_0.7–(B₂O₃)_0.3]_(1−x)–(Bi₂O₃)_x (where x = 0.05, 0.10, 0,15, 0.20, 0.25, and 0.3 mol%) glass systems have been explored and compared. For all samples, mass attenuation coefficients (μ/ρ) are estimated within 0.015–15 MeV photon energy range by MCNP5 simulation code and correlated with WinXCom results, which showed a satisfactory agreement between computed μ/ρ values by these both methods. Additionally, effective atomic number (Z_eff), effective electron density (N_eff), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), total atomic cross-section (σ_a), and total electronic cross-section (σ_e) are calculated by utilizing μ/ρ values. The μ/ρ, Z_eff, and N_eff are energy dependent and have higher values at the lowest energy and smaller values at higher energies. Moreover, using the G–P fitting method as a function of penetration depth (up to 40 mfp) and incident photon energy (0.015–15 MeV range), exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) are evaluated. Both 85TeO₂–15Bi₂O₃ (mol%) and 49TeO₂–21B₂O₃–30Bi₂O₃ (mol%) samples, by possessing higher values of Z_eff, exhibit minimum EBF and EABF values. Highest μ/ρ, Z_eff values and lowest HVL, TVL, MFP values of 49TeO₂–21B₂O₃–30Bi₂O₃ (mol%) sample indicated its better gamma-ray absorption capability among all selected glasses. Further, macroscopic effective 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) values for thermal neutron attenuation have been computed. Among all samples, 49TeO₂–21B₂O₃–30Bi₂O₃ (mol%) glass possesses a better Σ_R value for fast neutron attenuation, while the largest ‘σ_T’ value of 66.5TeO₂–28.5B₂O₃–5Bi₂O₃ (mol%) sample suggests its good thermal neutron absorption efficiency.