Impact of Bulk and Nano Bismuth Oxide on the Attenuation Parameters of Bentonite Barite Composites

Abstract

Since bentonite can absorb neutrons and gamma rays without sacrificing structural integrity, it is frequently used as the main shielding material in many nuclear installations. Recently, there has been a trend toward enhancing the shielding qualities of bentonite by adding various chemicals. However, the majority of the added materials either require particular handling procedures or pose health risks. The availability of environmentally friendly additives would be wonderful. The addition of barite to bentonite composites greatly raises the density of the specimens. Additionally, the performance of bentonite–barite composites as radiation shielding materials is improved by adding various amounts of bulk and nano Bi2O3 as a filler (6%, 13%, and 20%). Energy dispersive X-ray analysis (EDX) was used to determine the chemical makeup of the produced specimens. The scanning electron microscopy (SEM) pictures showed the samples’ cross-sections’ porosity and homogeneity. 241Am, 133Ba, 137Cs, and 60Co are radioactive sources that emit energies of 59.53, 80.99, 356.01, 661.66, 1173.23, and 1332.5 keV, respectively, and the NaI (Tl) scintillation detector was used in this investigation. The area under the peak of the observed energy spectra was measured using the Genie 2000 program in both the specimen’s absence and presence. The coefficients for linear and mass attenuation were calculated. To determine the theoretical mass attenuation coefficients, the XCOM program was utilized and then compared to the corresponding experimental values. Various radiation shielding parameters dependent on the linear attenuation coefficient were computed for each studied composite. These parameters include the mean free path (MFP), half value layer (HVL), and tenth value layer (TVL). Also, the Zeff and the EABF were determined for each specimen. According to the findings, bismuth oxide was added to bentonite–barite composites to reduce the transmitted flux through the specimens, which increased the LAC of the bentonite–barite composites. Furthermore, adding nanosized bismuth oxide particles increased the sample’s density and improved the material’s shielding properties. At a photon energy of 0.356 keV, the relative deviation (∆%) between the experimental nano- and micro values for Bi2O3 (20 wt%) was 12.1974, confirming that the nanoparticles increase attenuation efficiency.