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The use of geopolymer in place of ordinary Portland cement for concrete design and constructure is gaining attraction due to environmental and health considerations. Geopolymers must have high gamma radiation shielding competence in order for them to be useful for radiation shielding concrete. In an attempt to improve the gamma absorption capacity of a metakaolin-based geopolymer matrix, 10 % (GEO-10Y), and 20 % (G-20Y) yttria (Y2O3) was mixed with GEO through a solid-state reaction process. In this study, the influence of adding yttria on the physical and gamma shielding parameters of GEO was investigated. The densities of GEO, GEO-10Y and GEO-20Y were obtained as 2.28, 2.52 and 2.37 g/cm3, respectively. Through simulation using FLUKA code, the mass attenuation coefficients (MAC) and other relevant shielding quantities were estimated. The MACs of GEO, GEO-10Y, and GEO-20Y were within the range of 0.0213–6.6429 cm2/g, 0.0282–13.3923 cm2/g, and 0.0291–14.5136 cm2/g, respectively. The addition of yttria improved the gamma photon shielding competence of the metakaolin-based geopolymer by increasing the MAC and reducing photon buildup factors within 15 keV–15 MeV photon energy range. The shielding effectiveness of the yttria-doped GEO compares well with conventional shielding materials. Yttria-doped geopolymer can be used to produce effective and environmentally-friendly gamma shielding concrete.

Abstract Background Radiation shielding in radiology has historically been achieved with lead; however, there has been an increasing demand for radiation shielding to be more environmentally friendly. Barium has shown promise as a substitute in many radiology applications. This study aims to investigate a barium sulphate shield in protecting the thyroid and the eye lens during panoramic radiography. Methods During a simulated panoramic examination, an anthropomorphic phantom and a solid-state detector measured the radiation dose to the surface thyroid and the eye lens. The measurements were taken using no shield and a barium sulphate shield. A Welch's T-test was employed to compute the shield's effect on radiation. Two radiologists assessed the image quality with and without the thyroid shields. Results The dose reduction was between 66 and 75% for the barium shield at the thyroid. The dose reduction ranged between 15 and 61% in the eye region. Images using a barium shield were deemed adequate for diagnostic interpretation. Conclusions Barium shields effectively reduce the radiation dose in the thyroid region during panoramic radiography without degrading image quality. The dose reduction depends on the tube voltage and the area of interest.

Radiation shielding incorporates material between the radioactive source and environment to decrease exposure to hazardous radiation. It remains to be seen whether the addition of nanoparticles effectively increases the protection of tellurite glass system from further degradation under irradiation conditions. This study revealed the gamma radiation effects on tellurite glass. The tellurite glass samples were irradiated with 50 kGy and 100 kGy gamma ray, and subsequently analysed using X-ray diffractometer (XRD), atomic force microscopy (AFM), and ultraviolet–visible spectroscopy (UV–Vis). Gamma radiation increased the creation of non-bridging oxygen (NBO) and caused colour change on TZNETi and TZNETiAl glasses. Consequently, the addition of aluminium oxides (Al2O3) was found to lower the density of glass systems. The glass samples surface roughness increased, while the optical transmission spectra decreased after 50 kGy of gamma ray irradiation. Nevertheless, the glass system maintained its transparency even after irradiation. The mass attenuation coefficient (MAC) values represented the shielding effectiveness demonstrated by the investigated glass with the addition of Al2O3. The physical, structural, optical, and radiation shielding properties showed that 69.1TeO2–20ZnO–9Na2O–1Er2O3–0.3TiO2–0.6Al2O3 (TZNETiAl) sample exhibited strong shielding properties amongst the fabricated tellurite samples.

This paper examines gamma-ray shielding properties of SBC-Bx glass system with the chemical composition of 40SiO2–10B2O3–xBaO–(45-x)CaO– yZnO– zMgO (where x = 0, 10, 20, 30, and 35 mol% and y = z = 6 mol%). Mass attenuation coefficient (μ/ρ) which is an essential parameter to study gamma-ray shielding properties was obtained in the photon energy range of 0.015–15 MeV using PHITS Monte Carlo code for the proposed glasses. The obtained results were compared with those calculated by WinXCOM program. Both the values of PHITS code and WinXCOM program were observed in very good agreement. The μ/ρ values were then used to derive mean free path (MFP), electron density (Neff), effective atomic number (Zeff), and half value layer (HVL) for all the glasses involved. Additionally, G-P method was employed to estimate exposure buildup factor (EBF) for each glass in the energy range of 0.015–15 MeV up to penetration depths of 40 mfp. The results reveal that gamma-ray shielding effectiveness of the SBC-Bx glasses evolves with increasing BaO content in the glass sample. Such that SBC-B35 glass has superior shielding capacity against gamma-rays among the studied glasses. Gamma-ray shielding properties of SBC-B35 glass were compared with different conventional shielding materials, commercial glasses, and newly developed HMO glasse. Therefore, the investigated glasses have potential uses in gamma shielding applications.