• Energy Research

Abstract The role of BaO in the glassy structured Na2Si3O7 was investigated in the context of gamma radiations shielding parameters in the study. The mass attenuation coefficient, half layer value, and mean free path of the Na2Si3O7/BaO composites were calculated experimentally for the photons with the energies of 81 keV and 356 kev emitted from 133Ba point radioactive source. The same parameters were also calculated by Monte Carlo N-particle simulation (MCNP5) for the gamma photons which are emitted from 133Ba, 241Am, 99mTc, 177Lu, 192Ir, and 137Cs radioactive sources. The effective atomic number and effective electron density were determined by WinXCom software. Additionally, the scattered gamma photon intensity of the composites was realized for the energy of 364 keV and compared with the most utilized radiation shielding material lead. It was concluded that the composite having the highest BaO additive exhibits the best gamma photon absorption ability at all energies investigated.

Abstract In the present work, the very low-cost glassy structured sodium silicate (Na2Si3O7) matrix has been reinforced with micro-and nano-sized silver (Ag) particles in different weight percentages. The ionizing radiation shielding performances of the micro and nano-structured composites have been determined experimentally and theoretically for the first time. The experiments have been realized by the gamma-ray spectroscopy setup equipped with NaI(Tl) detector and Ba-133 point radioactive source. The radiation shielding performance has been discussed in the context of mass attenuation coefficient ( μ / ρ ) half-value layer (HVL), and mean free path (MFP). Besides, the theoretical research related to the radiation shielding ability of the samples has been carried out by using the Monte Carlo N-Particle Transport (MCNP) v6.2© simulation code. Since the experimental values and MCNP findings are very close to each other, MCNP simulation has been extended to a large incoming photon energy interval ranging from 25 keV to 1000 keV for both micro-and nano-structured composites. The particle size effect (PSE) on radiation shielding performance has been investigated and discussed. As a result of PSE research, it has been revealed that the addition of nanoparticles is more effective in the improvement of the radiation shielding for the lowest Ag concentration and low photon energies. Additionally, the radiation shielding capability of the composites has been discussed in the context of ambient dose equivalent, H ∗ ( 10 ) which is one of the operational quantities. By using the ambient dose equivalent definition, the ambient dose rate values of the composites have been calculated for the first time. In conclusion, it has been determined the composites with higher micro-and nano-Ag particle additives have considerably good radiation shielding ability against low energy photons that are mostly utilized in diagnostic and treatment medical applications.

© 2022 Elsevier LtdThe present study deals with the production of multifunctional polymer-based nanocomposites having the ability of ionizing radiation shielding and enhanced electric conductivity. In this context, it is aimed to obtain a new environmentally-friendly lead-free material with both high electric conductivity and ionizing radiation shielding features by reinforcing polycarbazole (PCz), a conductive polymer with BaO nanoparticles having a high effective atomic number. PCz matrix and BaO nanoparticles have been prepared by polymerization and co-precipitation methods, respectively. The surface morphology of the PCz matrix and nano BaO particles have been characterized by SEM and TEM images. Additionally, the optical band gaps of the samples have been calculated by using UV–visible spectroscopy. The lowest optical bandgap i.e. the highest electric conductivity has been observed for the 10 wt% BaO nanoparticle doped composite. On the other hand, the ionizing radiation shielding abilities of the samples have been evaluated in the context of mass attenuation coefficient, half-value layer, mean free path, effective atomic number, and effective electron density determined both experimentally and theoretically. Experimental measurements have been carried out by using NaI(Tl) detector and point radioactive sources (Ba-133, Cs-137, and Co-60) in the narrow beam geometry. The theoretical calculations have been performed by WinXCom software. A reasonable agreement between the experimental and WinXCom results has been found. Consequently, it has been determined that the maximum radiation shielding ability has been detected against 81 keV radiation for the PCz/30 wt% BaO nanocomposite. The composite has also a lower bandgap than pristine PCz. In this respect, the PCz/30 wt% BaO nanocomposite can have a promising potential in both medical and electronic applications that require high electric conductivity and ionizing radiation shielding ability.

Abstract The present study deals with determining the gamma-ray shielding parameters of the micro (μ)- Bi2O3, μ−WO3, nano (n)-Bi2O3, and n-WO3 reinforced Na2SiO3 (sodium metasilicate) composites experimentally and theoretically. The study has aimed to compare the size of reinforcing particles on the gamma-ray shielding ability of very low-cost and non-toxic Na2SiO3. In this context, the gamma-ray shielding performances of the samples containing different weight percentages of μ-Bi2O3, μ-WO3, n-Bi2O3, and n-WO3 particles have been evaluated by employing mass attenuation coefficient, half-value layer, and mean free path. The related parameters have been measured experimentally and also calculated by WinXCom. It has been revealed that Na2SiO3 composites having micro and nano-structured Bi2O3 and WO3 particles show good radiation shielding for 81 keV photons. In this respect, among all composites, the Na2SiO3/30% μ-WO3 sample has a promising potential to shield the ionizing radiation utilized in diagnostic imaging such as mammography, conventional X-ray machine, etc.

Abstract In the present study, the gamma-ray shielding performance of the epoxy polymer matrix has been tried to develop by loading the matrix with a natural stone named as Yahyali Stone (YS), The YS has been collected from the Fairy Chimneys of Kayseri, Turkey. The chemical composition of the YS, which has been analyzed by X-Ray Fluorescence (XRF) spectroscopy, revealed that the main components of the stone are Fe2O3 (75.28 wt%), SiO2 (17.21 wt%), and Al2O3 (4.24 wt%). The Epoxy/YS composites that include 5 wt%, 10 wt%, 20 wt% and, 30 wt% YS have been prepared by mechanical mixing technique. The experimental setup contained a133Ba, 137Cs, and 60Co point radioactive sources, which emit 81 keV, 356 keV, 662 keV, 1173 keV, and 1332 keV photons, and a NaI(Tl) detector. The gamma-ray shielding capability of the samples has been discussed in the context of mass attenuation coefficient (μ/ρ), half-value layer (HVL), and mean free path (MFP). The mass attenuation coefficient, HVL, and MFP have also been calculated by WinXCom software. The experimental and WinXCom software results have been compared and good consistency has been established between these results. Finally, the effective atomic number (Zeff) and effective electron density (Neff) have been calculated by using the interpolation method. In conclusion, it can be suggested that low cost, natural and non-toxic reinforcing YS material has a promising role in enhancing the radiation shielding ability of the epoxy matrix for low energy radiation applications.