The investigation of gamma-ray and neutron shielding parameters of Na2O-CaO-P2O5-SiO2 bioactive glasses using MCNPX code

Bioactive glasses are silicate glasses with sodium, calcium and phosphorus in its composition used to fulfill or support the functions of living tissues in the human body. The superiority of physical and mechanical properties of the bioactive glasses leads to the opportunity to use for radiation protection. From this point of view, radiation absorption parameters of nine bioactive glasses were reported in the present research. The mass attenuation coefficient (μ/ρ) for the selected bioactive glasses was calculated using MCNPX simulation code in the photon energy range 0.02–20 MeV and the results were compared with XCOM data. The values of μ/ρ calculated in two methods were found to support each other. Other vital parameters like half and tenth value layer (HVL and TVL), mean free path (MFP) and effective atomic number (Zeff) for the selected bioactive glasses were also evaluated by utilizing the μ/ρ. ICSW9 glass with more phosphate and sodium contents possess the lowest MFP, HVL and TVL values while has the highest Zeff values among the bioactive glasses under study. To evaluate the neutron protection performance of investigated bioactive glasses, effective removal cross-section values (ΣR) have been determined. The results showed that ICSW9 has also superior neutron attenuation properties. Additionally, exposure buildup factor (EBF) values were found with G-P fitting approach depending on the energy and penetration depths. The bioactive glasses with further equivalent atomic number possesses the minimum value of EBF. Keywords: Bioactive glass, Silicate glasses, Radiation protection, MCNP

Photon and neutron shielding characteristics of samarium doped lead alumino borate glasses containing barium, lithium and zinc oxides determined at medical diagnostic energies

WOS:000460704700308In the present work, we studied the radiation shielding parameters such as mass attenuation coefficients, effective atomic number, half value layer, mean free path, macroscopic effective removal cross-sections and neutron transmission function for samarium doped lead alumino borate glasses containing barium, lithium and zinc oxides at medical diagnostic energies (between 20 and 150 keV) using MCNPX code. The results showed that the photon attenuation depends on the type of modifier used (i.e. ZnO, BaO or Li2O) and also, upon the energy of the photon. The higher mass attenuation coefficients were found for the glass containing BaO. The results also revealed that the glass containing Li2O has the maximum effective atomic number between 20 and 40 keV. In addition, some important neutron shielding parameters such as macroscopic effective removal cross-sections (Sigma(R)) and neutron transmission function (N/N-0) have been calculated for investigated glass samples