The role of Bi2O3 on the gamma ray attenuation competence of lead-free silica borotellurite glasses between 0.284 and 1.275 MeV

Abstract

The radiation shielding features of TeO2-B2O3-SiO2 glasses with varying amounts of Bi2O3 were studied at several energies emitted from three radioisotopes: Cs-137, Co-60, and Na-22. The addition of Bi2O3 increases the mass attenuation coefficient (MAC) of the glasses, and Glass 6; the glass with the greatest Bi2O3 content, has the highest MAC out of all the investigated samples. At low energies, 0.284 MeV, there is a great difference between the MAC values of the glasses which increase greatly from Glass 1 to Glass 6 but at 0.826 MeV, the MAC values still increase but very slowly which demonstrated that the MAC is greatly affected by the composition of the glasses at low energies. We investigated the relationship between the density of the glasses and their linear attenuation coefficients (LAC). We found that the LAC of the samples increases as density increases from 3.21 to 4.15 g/cm3, and Glass 6 has a better attenuation performance than Glasses 1–5. The ratio of the mean free paths (MFP) of Glass 1 and Glass 6 (MFPglass1/MFPGlass6) was reported. The highest MFPglass1/MFPGlass6 ratio is equal to 1.75 and occurs at 0.284. The average tenth value layer (TVL̅) of each glass was calculated at two energies; 0.284 MeV and 0.662 MeV, both of which are energies emitted from Cs-137. From the TVL̅results, increasing the Bi2O3 content of the glasses has a positive impact on the thickness of the glasses needed to attenuate the incoming radiation to safe levels.