Gamma radiation shielding and health physics characteristics of diaspore-flyash concretes

Radiation Shielding Concrete with alternate constituents: An approach to address multiple hazards

Radiation Shielding Concrete (RSC) is a superior alternative to many conventional and modern shields against gamma and neutron radiation hazards. The present work is the first comprehensive review on utilization of alternate materials, emphasizing hazardous industrial byproducts, as constituents of RSC. Such usage enhances the performance, sustainability, and affordability of RSC. Added advantages are the immobilization of wastes and the conservation of natural resources for RSC. The review analyses incorporation of ferrous and non-ferrous slags, mines wastes, plastics, red mud, cathode ray tube's glass, metallic wastes, fly ash, silica fume, and miscellaneous residues. Besides, utilization of fibers, nanoparticles, and calcined clay is investigated. The influence on shielding efficiency is adjudged by scrutinizing changes in parameters such as half-value layer and linear attenuation coefficients. Similarly, variations in mechanical and durability properties are investigated and compared. The underlying responsible factors related to the physical, chemical and morphological characteristics of materials and their consequences on RSC's behavior are correlated. In association with alternatives, the advantages, disadvantages, and possible treatment methods are discussed. The country-wise, material-specific, and progressive research trends are revealed to facilitate future work in this upcoming field. Finally, conclusions are drawn with exposition of current bottlenecks and scope of future research.

Gamma radiation shielding properties of some Bi-Sn-Zn alloys

We investigate the gamma radiation shielding properties of some Bi-Sn-Zn alloys. For this study, we synthesised five bismuth-based lead-free alloy samples using the melt quench technique with the composition Bi50Sn[Formula: see text]Zn[Formula: see text] where [Formula: see text] Apart from physical parameters such as the weight, density, and thickness of the alloy samples, we estimated their optimum thickness range at photon energies of 122, 511, 662, and 1250 keV. The mass attenuation coefficients and effective atomic number, measured experimentally, were found to be in close agreement with values computed using WinXCom software, within a ± 4% error. From the transmitted photon spectra, the radiation protection efficiency (RPE) was determined and analysed for different alloy compositions. A correlation between RPE and effective atomic number was established at different photon energies. The Bi50Sn50 binary alloy composition is reported to exhibit maximum shielding efficiency.

Neutron and photon scattering properties of high density concretes used in radiation therapy facilities: A Monte Carlo study

In the current study the neutron and photon scattering properties of some newly developed high density concretes (HDCs) were calculated by using MCNPX Monte Carlo code. Five high-density concretes including Steel-Magnetite, Barite, Datolite-Galena, Ilmenite-ilmenite, Magnetite-Lead with the densities ranging from 5.11 g/cm3 and ordinary concrete with density of 2.3 g/cm3 were studied in our simulations. The photon beam spectra of 4 and 18 MV from Varian linac and neutron spectra of clinical 18 MeV photon beam was used for calculations. The fluence of scattered photon and neutron from all studied concretes was calculated in different angles. Overall, the ordinary concrete showed higher scattered photons and Datolite-Galena concrete (4.42 g/cm3) had the lowest scattered photons among all studied concretes. For neutron scattering, fluence at the angle of 180 was higher relative to other angles while for photons scattering fluence was maximum at 90 degree. The scattering fluence for photons and neutrons was dependent on the angle and composition of concrete. The results showed that the fluence of scattered photons and neutrons changes with the composition of high density concrete. Also, for high density concretes, the variation of scattered fluence with angle was very pronounced for neutrons but it changed slightly for photons. The results can be used for design of radiation therapy bunkers.

Attenuation properties of radiation shielding materials such as granite and marble against γ-ray energies between 80 and 1350 keV

In this study, the γ-ray energy-dependent mass and linear attenuation coefficients of various granite and Turkish marble species have been experimentally obtained. Radionuclides (133Ba, 137Cs, 60Co and 22Na) with point geometry were used as γ-ray sources. The absorption capacity of each sample at nine γ-ray energies was measured using a high resolution γ-ray spectrometer equipped with a high purity germanium (HPGe) detector. To obtain the precision of the results (1σ standard deviation of the single value), this procedure was repeated six times for each species of granite and marble, respectively. The energy-dependent mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), the half (HVL) and the tenth value layer (TVL) were calculated following that the MAC and LAC results were compared to the literature values.