Optical absorption and gamma-radiation-shielding parameter studies of Tm³⁺-doped multicomponent borosilicate glasses

Different concentrations (0.1-2.0 mol%) of Tm³⁺-doped multicomponent borosilicate glasses with 10 mol% Li₂O (alkali) or MgO (alkaline) have been synthesized and their optical absorption and radiation shielding features were studied. For both Li₂O and MgO series 0.5 mol% Tm³⁺-doped glass samples, the evaluated Ω_λ (λ = 2, 4, and 6) Judd-Ofelt (JO) intensity parameters from experimental oscillator strengths were used in estimating the radiative transition probabilities (A_R), branching ratios (β_R), and radiative lifetimes (τ_R) for several emission transitions. Using the XCOM software, the mass attenuation coefficients (μ/ρ) for all the fabricated glasses were evaluated within the 0.015-10 MeV energy range. Also, the (μ/ρ) values were calculated at 0.356, 0.662, 1.173, and 1.33 MeV photon energies by MCNP5 simulation code and the results were compared with those obtained by XCOM. The (μ/ρ) values for Li₂O, as well as MgO series glasses, increase with the addition of Tm₂O₃ and these values for MgO series glasses are slightly higher with respect to Li₂O series glasses. From the (μ/ρ) values, effective atomic number (Z_eff), half-value layer (HVL), and mean free path (MFP) were calculated and the HVL and MFP results revealed that high-energy photons have more penetration into a glass sample compared to low-energy photons. Further, geometric progression (GP) fitting method was utilized to calculate the exposure buildup factor (EBF) within the 0.015-15 MeV energy range. The 2.0 mol% Tm₂O₃-doped glasses show a better ability to attenuate gamma-rays in comparison to other glass samples, so the addition of Tm₂O₃ content leads to improvement of the shielding efficiency of the prepared glasses. (orig.)