• 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 Analytic and stochastic methods were proposed for the determination of gamma-ray radiation shielding properties of the glassy composites. Radiation shielding properties such as mass attenuation coefficients, effective atomic numbers, effective electron numbers, build-up factors (exposure build-up factors and energy absorption build-up factors) can be determined with these techniques. A versatile quaternary composite was studied with different mass ratios in order to optimize the gamma radiation attenuation. Exposure build-up factors (EBFs), energy absorption build-up factors (EABFs), effective atomic numbers (Zeff) and effective electron densities (Neff) were calculated via BXCOM. Furthermore, MCNP transport code, version of 6.2, was used to simulate the mass attenuation coefficients (μ/ρ) and the half-value layers (HVLs) of the composites. Since they are compatible, simulation and BXCOM results denote that these methods can be used to determine the radiation shielding parameters for the glassy composites for which there are no satisfactory experimental values available. All in all, the optimum mass ratio, having the highest radiation attenuation, was determined as [Na2Si3O7/Bi2O3(65/35)/B2O3(2)/Sb2O3(11)], so that glassy composite might be preferred as a radiation shield in various applications. The quaternary glassy composites investigated in this study, performs better than ordinary concrete, getting close to pure lead as a radiation shield.

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.