Shielding properties of glasses with different heavy elements additives for radiation shielding in the energy range 15–300 keV

Investigation of natural radionuclides and radiation shielding potential of some commonly used building materials in Northwestern Nigeria

This study assessed the gamma-ray shielding potential of clay, sand, gypsum and kaolin commonly used as a building material in Northwestern, Nigeria. The radiological status of the samples was first evaluated by determining the activity concentrations of 238U, 232Th and 40K using NaI (Tl) detector after which elemental composition and mass density were determined using Neutron Activation Analytical Technique. After which the mass attenuation coefficients (MAC), linear attenuation coefficients (LAC), half value layer (HVL), tenth value layer (TVL), and effective atomic number (Zeff) were determined experimentally and theoretically using standard point sources of 137Cs and 60Co photon peaks (0.662 and 1.332, 1.173) MeV and Py-MLBUF software. The activity concentrations were found to range from 51 to 59 Bq kg-1 with a mean value of 59 Bq kg-1 for 238U, 24 to 27 Bq kg-1 with a mean value of 29 Bq kg-1 for 232Th, and 219 to 247 Bq kg-1 with a mean value of 247 Bq kg-1 for 40K which were about within the world recommended values of 33, 45 and 420 Bq kg-1 respectively. The results of the elemental compositions show that Si, Al, K, Fe, and Ba in clay and sand samples have concentrations in the range of 36.83-78.48%, 1.92-26.05%, 6.33-21.96%, 2.39-19.09%, and 0.09-1.44%, respectively, while in kaolin and gypsum, results revealed that Si, Al, K, Fe, and Ca range between 0.34 and 65.52%, 1.14-35.82%, 0.00-12.12%, 0.00-5.77%, and 0.00-96.6%, respectively. However, the concentrations of other elements such as Mg, Ti, Mn, Zn, Na, and Ba varied significantly with the samples. The results showed that clay has an average density of 1.96 g/cm3, sand has 2.32 g/cm3, kaolin has 2.63 g/cm3, and gypsum has the highest density with a value of 2.66 g/cm3 compared to other samples. During the measurements, a thallium-activated sodium-iodide NaI (TI) detector was used. A narrow beam transmission geometry condition was adopted for the measurements to ensure minimal scattered radiation. Absorption and attenuation of gamma beams as a function of sample thickness against gamma energy generally exhibit an increasing gamma ray behaviour as the sample thickness increases from 1 to 3 cm. The results showed that the gypsum, kaolin, sand, and clay were capable of attenuating 63.5%, 61.5%, 58.4%, and 44.2 of gamma-ray photons of energy 0.662 MeV at 3 cm thickness %, respectively, and 40.6%, 32.9%, 30.6%, and 27.3% of gamma energy 1.332 MeV at 3 cm thickness, respectively. The results showed that MAC, LAC, and Zeff of all the samples decreased with an increase in photon energy, while those of HVL and TVL increased. The experimental results for all the gamma-ray shielding parameters were found to be in good agreement with the theoretical values obtained using Py-MLBUF. The results have shown that all the samples have similar photon attenuation behaviours; however, gypsum has the best shielding potential than kaolin and this is attributed due to its highest density value.

Medical-Radiation-Shielding Film Fabricated by Imitating the Layered Structure Pattern of Abalone Shell and Verification of Its Shielding Effect

Radiation-shielding clothing for medical workers must be light and thin, thus ensuring flexibility. However, controlling the thickness and weight is limited by shielding performance requirements. This study aims to improve shielding performance by considering a shielding structure that mimics the internal structure of an abalone shell. Two shields were produced: a sheet made with a carrier process using a liquid polymer and tungsten mixture, and a fillet made by compounding the same material and laminated using a heat-treatment press after the injection process. The tungsten content and thickness were the same at 85 wt% and 0.3 mm, respectively. In the high-energy region, the shielding film based on the laminated structure of abalone shells showed a shielding rate that was higher by more than 7%. Compared to that of a 0.3 mm lead plate, the shielding ratio of the shielding film was approximately 16% lower at 120 kVp, thereby confirming the radiation-shielding effect of the layered-structure shielding film. Therefore, it is concluded that the laminated structure of the shielding film, which is identical to the internal laminated structure of the abalone shell, expands the impact area of incident radiation and attenuates the energy intensity, thereby improving the medical-radiation-shielding performance.

Attenuation properties of hybrid nanocomposite film containing Ce2O, GO, and α-Al2O3 nanoparticles for high energy radiations

The use of diagnostic radiation in medical centers has spread due to the incidence of various diseases. Thus, it is essential that patients and medical staff wear protective clothing to protect themselves from their harmful effects. In the past, lead protective clothing has been used; however, the toxicity and heaviness of lead have limited the tendency to use these clothing. Recently, nanocomposites containing heavy element nanoparticles have been introduced as an alternative to lead coatings. In this study, hybrid nanocomposites containing ceria (CeO2), alumina (Al2O3), and graphene oxide (GO) nanoparticles were studied for this purpose. Ceria, alumina, and graphene oxide nanoparticles were mixed with polyethylenevinylacetate (EVA) dissolved in chloroform and casted on a glass plate to form nanocomposite films. The prepared nanoparticles and films were characterized by Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscope, Thermal Gravimetric Analysis, and Energy Dispersive X-ray Analysis, and then the attenuation properties of the films against high-energy radiation (120 kV) were studied in two narrow and broad beam geometries. The results showed that hybrid films, despite having a lower percentage of nanoparticles, showed better attenuation properties, which indicated the synergistic effect of nanoparticles with different mechanisms in attenuating the radiations. The attenuation ability of these films was considerable due to their lower density compared to lead. The fabricated hybrid nanocomposite films with a suitable performance in attenuation of high-energy radiations used in therapeutic diagnostics, can be proposed as a suitable alternative to conventional lead clothing.

Effect of WO3 on the radiation shielding ability of TeO2–TiO2–WO3 glass system

In this study, glass composition based on tungsten oxide (WO3) doped tellurium, titanium glasses: (100 − x − y) TeO2–xTiO2–yWO3: where (x = 5) and (y = 5, 10, 15, 20, 25) coded as TT5W5, TT5W10, TT5W15, TT5W20, and TT5W25 were investigated for shielding properties against ionizing radiation. Gamma radiation shielding parameters such as mass attenuation coefficients (MAC) are calculated through MCNPx code and Phy-X/PSD software in the energy range of 0.015–15 MeV. Obtained MAC values are then used to calculate other gamma radiation shielding parameters such as mean free path (MFP) and effective atomic number (Z eff). Besides this, the exposure buildup factor (EBF) was also calculated by using EXABCal software at different penetration depths (PDs) in the energy range of 0.015–15 MeV. Sample TT5W25, which has a larger WO3 content of 25 mol% shows higher values of MAC and lower values of MFP among all the examined glass samples. Our investigated TeO2–TiO2–WO3 glass samples possess the lowest MFP values in comparison with the different types of concretes and commercially available shielding glasses. In addition, fast neutron shielding characteristics in light of fast neutron removal cross-section have also been computed. Glass sample TT5W25 possesses the higher values of fast neutron removal cross-section as compared to the other glass samples. The results indicate that the adding up of WO3 improves shielding against the fast neutron and gamma radiation.

A Comprehensive Evaluation of the Attenuation Characteristics of Some Sliding Bearing Alloys under 0.015-15 MeV Gamma-Ray Exposure

In this study, three different sliding bearing alloy samples were investigated in terms of their performance on attenuation characteristics and behavioral attitudes under 0.015-15 MeV gamma-ray exposure. Accordingly, different types of advanced calculation methods were utilized to calculate the radiation shielding parameters. Next, several gamma-ray shielding parameters and exposure rates in addition to fast neutron removal cross-section were determined. Furthermore, exposure and energy absorption buildup factors were determined by using G-P fitting method. Mass attenuation coefficients (MAC) values were recorded as 2.5246, 2.5703, and 2.5827 (cm2/g) for Alloy1, Alloy2, and Alloy3 samples at 15 MeV photon energy, respectively. At 40 mfp, the highest EBF values were reported as 1,376,274, 1,003,593, and 969,373 for Alloy1, Alloy2, and Alloy3 samples. The results of this extended investigation showed that the Alloy3 sample with the highest Pb reinforcement amount has superior shielding capability among the investigated samples. It can be concluded from the results that substitution of Pb with Bi in the recent alloy structure has a monotonic effect on different types of shielding parameters. Therefore, it can also be concluded that Pb is a remarkable tool for the improvement of the shielding properties of studied alloy structures.

Transmission Factor (TF) Behavior of Bi2O3–TeO2–Na2O–TiO2–ZnO Glass System: A Monte Carlo Simulation Study

The main objective of the present work was to assess the gamma radiation shielding competencies and gamma radiation transmission factors (TFs) for some tellurite glasses in the form of Bi2O3–TeO2–Na2O–TiO2–ZnO. MCNPX general-purpose Monte Carlo code (version 2.6.0) was utilized for the determination of TF values at various well-known radioisotope energies for different glass thicknesses from 0.5 cm to 3 cm. Moreover, some important gamma ray shielding properties were also determined in the 0.015–15 MeV energy range. The results show that glass densities were improved from 5.401 g/cm3 to 6.138 g·cm3 as a function of Bi2O3 increment in the glass composition. A S5 glass sample with the maximum Bi2O3 additive was reported with superior gamma ray shielding properties among the studied glasses. It can be concluded that Bi2O3 can be used as a functional tool in terms of improving glass density and, accordingly, gamma ray shielding attenuation properties of tellurite glasses, where the role Bi2O3 is also critical for other material properties, such as structural, optical, and mechanical.

Optical and radiation shielding characteristics of tellurite glass doped with different rare-earth oxides

Shielding glass materials doped with heavy metal oxides show an improvement in the effectiveness of the materials used in radiation shielding. In this work, the photon shielding parameters of six tellurite glass systems doped with several metal oxides namely, 70TeO2-10P2O5- 10ZnO- 5.0PbF2- 0.0024Er2O3- 5.0X (where X represents different doped metail oxides namely, Nb2O5, TiO2, WO3, PbO, Bi2O3, and CdO) in a broad energy spectrum, ranging from 0.015 MeV to 15 MeV, were evaluated. The shielding parameters were calculated using the online software Phy-X/PSD. The highest linear and mass attenuation coefficients recorded were obtaibed from the samples containing bismuth oxide (Bi2O3), and the lowest half-value layer and mean free path were recorded among the other samples. Furthermore, the shielding effectiveness of tellurite glass systems was compared with commercial shielding materials (RS-369, RS-253 G18, chromite, ferrite, magnetite, and barite). The optical parameters viz, dispersion energy, single-oscillator energy, molar refraction, electronic polarizability, non-linear refractive indices, n2, and third-order susceptibility were measured and reported at a different wavelength. Bi2O3 has a strong effect on enhancing the optical and shielding properties. The outcome of this study suggests the potential of using the proposed glass samples as radiation-shielding materials for a broad range of imaging and therapeutic applications.

Thermal stability, mechanical properties, and gamma radiation shielding performance of polyvinyl chloride/Pb(NO3)2 composites

Radiation shielding composites based on polyvinyl chloride (PVC) reinforced with different weight ratios of Pb(NO3)2 (5, 10, and 20 wt%) were prepared using the solution-casting technique. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy, and tensile testing method were used to characterize the PVC composite films. FTIR and XRD investigations illustrate the structural change and modification of the as-prepared PVC composites. The morphological analysis of the composite revealed that Pb(NO3)2 was dispersed uniformly within PVC polymer matrix. TGA revealed that the incorporation of Pb(NO3)2 improved the thermal stability of the investigated composites, whereas adding Pb(NO3)2 to the polymer matrix worsened its tensile properties. The as-prepared composite films were investigated for radiation-shielding of gamma-rays radioactive point sources (241Am, 133Ba, 137Cs, and 60Co). Linear attenuation coefficient (μ, cm−1), mass attenuation coefficient (μ/ρ, cm2/g), and half-value layer (HVL, cm) have been estimated from the obtained data using the MicroShield program. Reasonable agreement was attended between theoretical and experimental results. The deviation between the experiment and theoretical values of mass attenuation coefficient is being to be lower than 9%, and this can be correlated to the good distribution of Pb(NO3)2. The results revealed that adding Pb(NO3)2 to PVC polymer composites improved their mass attenuation coefficient.

Effect of TiO2/V2O5 substitution on the optical and radiation shielding properties of alkali borate glasses: A Monte Carlo investigation

In this paper, we used Geant4 Monte Carlo simulations to investigate the effect of TiO₂/V₂O₅ substitution on the radiation shielding properties of alkali borate glasses in the chemical form of 30Li₂O+55B₂O₃+5ZnO + xTiO₂+(10 - x)V₂O₅, where x = 0, 2.5, 5, 7.5, and 10 mol%. Also, the optical properties were examined by evaluating several factors such as molar refraction (R_m), metallization criterion (M), molar polarizability (α_m), dielectric coefficients (static and optical), optical transmission (T), and reflection loss (R_L). The radiation shielding properties of the tested glasses were estimated by determining the mass attenuation coefficient, and other related factors such as the tenth value layer (TVL), the mean free path (MFP), the electron total stopping powers (Ψ_e) and the electron continuous slowing down approximation range (CSDA) (Φ_e) for different energy values. The results of Geant4 Monte Carlo were compared with the theoretical values calculated by XCOM platform. The results revealed that the TiO₂/V₂O₅ substitution had a remarkable influence on the gamma shielding properties for the tested glasses. On the other hand, the optical properties slightly changed by the TiO₂/V₂O₅ substitution. The gamma shielding properties of the tested glasses were compared with many samples in terms of MFP. The present glasses showed superior features to apply for optical and radiation shielding applications.