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Near-zero magnetic shielding systems (MSSs) can provide basic experimental environments for extremely weak magnetic measurements. Reducing the internal magnetic field of MSS is the crucial element of high-sensitivity measurements, which is related to the shielding material flux. As an effective way to regulate the material remanence, degaussing reconstructs the magnetic balance with the geomagnetic field. However, previous research studies mainly focused on the optimization of material degaussing, with few considering the practical application scenarios of MSS. In this work, a numerical modeling method is proposed to realistically depict the balancing process, and the mapping relationship between the internal magnetic field of the MSS and the degaussing current is established. First, the magnetic field source analysis is carried out, and the internal magnetic field fluctuations of the MSS during degaussing are decomposed into multi-harmonic components. Then, the phase and amplitude changes of the hysteresis loop are simulated to predict the residual field. Thereafter, the effectiveness of the method is verified by a magnetic shielding cylinder. The experimental results indicate that the slight difference in material remanence has a negligible effect on the residual field. This work has potential application value in the research of degaussing technology. [ABSTRACT FROM AUTHOR]

The topology of the applied magnetic field is an important design aspect of Hall thrusters. For modern Hall thrusters, the magnetic field topology most often features curved lines with a concave (negative) curvature upstream of the field's peak and a convex (positive) curvature downstream. Additionally, the advent of the magnetic shielding technique has resulted in Hall thruster designs with non-conventional field topologies that exhibit high degrees of concavity upstream of the field's peak. In this article, a detailed study is carried out on the effects that the magnetic field curvature has on the plasma discharge in a 2D configuration representative of a Hall thruster's radial–azimuthal cross section. The analyses are performed for discharges of three propellants of high applied interest: xenon, krypton, and argon. For each propellant, high-fidelity electrostatic reduced-order particle-in-cell (PIC) simulations are performed with various degrees of positive and negative curvatures of the magnetic field. Corresponding 1D radial PIC simulations are also performed for xenon to compare the observations against the 2D results. Most notably, it is observed that the instability spectra in the positive-curvature cases are mostly dominated by electron cyclotron drift instability, whereas the modified two stream instability is dominant in the negative-curvature cases. The distributions of electron and ion temperatures, in particular, as well as the contribution of various mechanisms to electrons' cross-field transport show notable variations between the positive and negative curvature values. Finally, the field curvature is observed to majorly influence the ion beam divergence along the radial and azimuthal coordinates. [ABSTRACT FROM AUTHOR]

The aim of the present study is to assess the shielding performance of a novel lead-free epoxide material against ionizing radiation. The effect of variation in particle size and concentration of tin oxide (SnO), which was added to epoxy resin polymer (ER), on its radiation shielding properties has been investigated in this research. Ten samples of ER samples incorporated with different concentrations (0%,20%,40%,60%) of SnO microparticles, nanoparticles, and both sizes combined were prepared and assessed. The linear attenuation coefficients (LAC) were measured experimentally through the collimated gamma-ray beam at 0.0595 MeV, 0.6617 MeV, 1.1730 MeV, and 1.330 MeV emitted from Am-241, Cs-137 and Co-60, respectively (to cover all energy range of gamma rays) for all samples with various concentrations and particle sizes of SnO. The other radiological shielding parameters such as half value layer (HVL), tenth value layer (TVL), and radiation protection efficiency (RPE) were estimated and compared for all different samples. The results prove that the increasing of the concentration and reducing the particle size of SnO leads to the enhancement of the radiation protection properties of the ER polymer. Moreover, it was observed that the incorporation of SnO micro- and nanoparticles together improves the radiation shielding properties of ER samples. Conclusively, the reinforcing of ER polymer material matrix by micro/nanoparticles of SnO as composite with enhanced radiation shielding specifications was highlighted. [ABSTRACT FROM AUTHOR]

The aim of the present study is to assess the shielding performance of a novel lead-free epoxide material against ionizing radiation. The effect of variation in particle size and concentration of tin oxide (SnO), which was added to epoxy resin polymer (ER), on its radiation shielding properties has been investigated in this research. Ten samples of ER samples incorporated with different concentrations (0%,20%,40%,60%) of SnO microparticles, nanoparticles, and both sizes combined were prepared and assessed. The linear attenuation coefficients (LAC) were measured experimentally through the collimated gamma-ray beam at 0.0595 MeV, 0.6617 MeV, 1.1730 MeV, and 1.330 MeV emitted from Am-241, Cs-137 and Co-60, respectively (to cover all energy range of gamma rays) for all samples with various concentrations and particle sizes of SnO. The other radiological shielding parameters such as half value layer (HVL), tenth value layer (TVL), and radiation protection efficiency (RPE) were estimated and compared for all different samples. The results prove that the increasing of the concentration and reducing the particle size of SnO leads to the enhancement of the radiation protection properties of the ER polymer. Moreover, it was observed that the incorporation of SnO micro- and nanoparticles together improves the radiation shielding properties of ER samples. Conclusively, the reinforcing of ER polymer material matrix by micro/nanoparticles of SnO as composite with enhanced radiation shielding specifications was highlighted. [ABSTRACT FROM AUTHOR]

The aqueous solution cast method was used to create the biodegradable polymer nanocomposite (PNC) films from a blend of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) PVP (70/30 wt %) and Fe2O3 nanoparticles (NPs). These PNC films were characterized using X-ray diffraction, scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, and ultraviolet-visible spectroscopy. XRD and FTIR results indicate that Fe+ 3 NPs interact with the host polymer. Optical, electrical, mechanical, and radiation shielding measurements were performed on the PNC films. From the optical measurements, the indirect optical band gap drops from 4.86 eV for the pure blend to 4.26 eV at the greatest NPs concentration. Optical limiting characterization shows that the output power of He-Ne and solid-state green laser beams is reduced from 22.98 to 3.6 mW and 6.59 to 1.4 mW, respectively, when the Fe2O3 NPs content in the blend matrix is increased to 6 wt %. The NGCal software was utilized to calculate nuclear radiation shielding properties. The findings demonstrated that when the concentration of Fe2O3 rose, the PNC films half-value layer and mean free path decreased. Mechanical measurements demonstrate that increasing the Fe2O3 content significantly improves nanocomposite films' yield and tensile strength. Tensile strength is measured at 27.03 MPa for the composite film containing 6 wt % Fe2O3, which is significantly higher than the 8.66 MPa of the pure (PVA-PVP) film. Compared to the other samples under examination, the 6 wt % Fe2O3 sample yielded the best results (based on the analyzed optical, electrical, mechanical, and radiation shielding properties). [ABSTRACT FROM AUTHOR]

A five pressured diatomite clay materials samples were produced as a mixture of diatomaceous earth mineral and sodium silicate for the purpose of this investigation. The forming pressures ranged from 22.84 MPa to 114.24 MPa, and the samples were formed under a variety of conditions. The ratio of Na2SiO3 to the total mass of the produced pressed samples was maintained at precisely 15 wt.% throughout the process. Through the process of increasing the forming pressure, the density of the pressed samples was increased by ~ 11%. For the purpose of determining how the forming pressure will affect the shielding capacity, the Monte Carlo simulation was applied. The linear attenuation of the fabricated pressed diatomite samples improves from 0.123 to 0.136 cm−1 when the forming pressure is increased from 22.84 MPa to 114.24 MPa. By increasing the pressure from 22.84 MPa to 114.24 MPa, the half-value thickness reduced from 5.63 cm to 5.09 cm, and the thickness equivalent = 1 cm of pure Pb metal decreased from 10.09 cm to 9.12 cm. It was found that elevating the forming pressure resulted in an augmentation of the fast neutron removal for the artificially manufactured pressed diatomite samples. [ABSTRACT FROM AUTHOR]

The aqueous solution cast method was used to create the biodegradable polymer nanocomposite (PNC) films from a blend of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) PVP (70/30 wt %) and Fe2O3 nanoparticles (NPs). These PNC films were characterized using X-ray diffraction, scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, and ultraviolet-visible spectroscopy. XRD and FTIR results indicate that Fe+ 3 NPs interact with the host polymer. Optical, electrical, mechanical, and radiation shielding measurements were performed on the PNC films. From the optical measurements, the indirect optical band gap drops from 4.86 eV for the pure blend to 4.26 eV at the greatest NPs concentration. Optical limiting characterization shows that the output power of He-Ne and solid-state green laser beams is reduced from 22.98 to 3.6 mW and 6.59 to 1.4 mW, respectively, when the Fe2O3 NPs content in the blend matrix is increased to 6 wt %. The NGCal software was utilized to calculate nuclear radiation shielding properties. The findings demonstrated that when the concentration of Fe2O3 rose, the PNC films half-value layer and mean free path decreased. Mechanical measurements demonstrate that increasing the Fe2O3 content significantly improves nanocomposite films' yield and tensile strength. Tensile strength is measured at 27.03 MPa for the composite film containing 6 wt % Fe2O3, which is significantly higher than the 8.66 MPa of the pure (PVA-PVP) film. Compared to the other samples under examination, the 6 wt % Fe2O3 sample yielded the best results (based on the analyzed optical, electrical, mechanical, and radiation shielding properties). [ABSTRACT FROM AUTHOR]

CubeSat and small satellites play a very important role in modern space exploration. Their success and diverse capabilities rely on the development of efficient and compact sub‐systems. This task is not trivial due to multiple challenges posed by their small size and mass, and the solution calls for conceptually new designs for the fabrication and integration of complex miniaturized satellite components. The importance of additive techniques in small satellite manufacturing is steadily increasing as they enable rapid, large‐scale production of sophisticated architectures, such as hollow, webbed parts with a cell‐like structure similar to animal bone, with lower mass and improved functionality. Moreover, these architectures feature higher strength, enhanced heat transfer, and efficient thermal and electromagnetic radiation shielding. When compared to traditional subtractive technologies like cutting and milling, additive manufacturing proves to be more versatile and effective in realizing architectures with an increasing intricacy of shapes, structures, and compositions. The perspective explores the suitability of 3D printing in various satellite production tasks, including the propulsion system components and satellite elements. Looking ahead, the challenges and advantages of integrating 3D printing technology into satellite production, emphasizing the need for continuous development through consolidated, proactive collaborative efforts of many devoted teams are outlined. [ABSTRACT FROM AUTHOR]

The continuous development of ionizing radiation in medical imaging and treatment, nuclear reactors, food irradiation, and other fields is accompanied by potential risks. It protects related equipment and personnel by adopting radiation shielding materials to reduce irradiation. Due to the advancement of science and technology, many high‐performance radiation protection materials have been reported. Ionizing radiation is a complex environment involving X‐ray imaging, radiation therapy, nuclear power operation, and space radiation. Irradiation energy, irradiation type, and the measurement of shielding material have essential effects on shielding efficiency. However, there has not been a general review of the preparations and properties of ionizing radiation shielding materials in the light of different matrixes in recent years. Herein, a comprehensive overview of recent advancements in radiation shielding materials, categorized into alloys, concretes, glasses and ceramics, and polymer composites, is presented. Furthermore, the synthesis methods employed for these materials and their respective radiation shielding properties are discussed. Finally, the current research gap and possible future scope of radiation shielding materials are proposed. [ABSTRACT FROM AUTHOR]

The transport of fission products in molten salt reactors has attracted much attention. However, few codes can completely describe the transport characteristic, though the migration of fission products in the molten salt reactor is essential to estimate the source term, decay heat, and radiation shielding. This study built a program named ThorFPMC (Thorium Fission Products Migration Code) that can handle the multi-physics transport characteristic based on the flow burnup code ThorMODEc (Thorium MOlten Salt Reactor Specific DEpletion Code). A problem-related depletion chain compression method was applied to decrease the order of the solve matrix. The matrix exponential and splitting methods were applied to solve the steady state and transient calculation, respectively. Error analysis showed that for a specific problem, the simplified depletion chain matrix index method could solve the fission products migration equation with an arbitrary time-step with high speed (s) and high precision (10−4); the splitting method could reach a precision of 10−2 level for the full fuel depletion chain, multi-nodes, and transient problems. Compared to the Strang splitting method, the perturbation splitting method has higher precision and less time consumption. In summary, the developed programmer could describe the migration effect of fission products in molten salt reactors, which provides a significant tool for the design of molten salt reactors. [ABSTRACT FROM AUTHOR]

This study explores the structural, radiation, and optical properties of cyclosilicates minerals (CMs), providing comprehensive analyses of molar volumes, densities, band gap values, and effective atomic numbers. The structural properties were found to be dependent on the correlations with the interatomic interactions derived from the analysis of Hirshfeld topological surfaces (HTSs) and their voids. In examining a broad energy spectrum from 0.015 to 15 MeV, the study focuses on mass attenuation coefficient (MAC) and linear mass attenuation coefficient (LAC). Results show that MAC values are the highest for the BaTi(SiO3)3 crystal, highlighting its superior γ‐ray attenuation capabilities among other CMs. The study finds that Hirshfeld volume, and surface ranged between 344.21 and 2640.98 Å3 and 388.91 and 1326.97 Å2, reveals distinct electron density distribution characteristics in CM materials. The study probes the impact of HTSs on structural (113 < Vm < 686 cm3/mol), optical (1.95 < n < 2.38), and radiation shielding (13.0 < LAC < 102.0 1/cm at E = 15.0 keV) values, demonstrating that altering the O...A (A = atom in the CM crystal) interactions align with the charge density, potentially tuning other physical values. [ABSTRACT FROM AUTHOR]

Heavy-weight concrete (HWC) is a widely adopted radiation shielding material in the nuclear industry. In this study, two kinds of high-density aggregate, namely, iron sand (IS) and steel slag coarse aggregate (SSCA), were adopted to fully replace river sand and natural coarse aggregate, respectively, producing ultra-heavy-weight concrete (UHWC) with a unit weight >3800 kg/m3, to ensure excellent radiation shielding performance. However, IS and SSCA seriously impaired the passing ability of UHWC as the cement paste could not hold the IS and SSCA as firmly as natural aggregates, owing to their high density. To overcome this, the rheology of UHWC should be optimised by partially replacing the cement with superfine silica fume (SSF) and using a suitable amount of superplasticiser (SP) to enhance the wet packing density (WPD). A total of 28 UHWC mixes with different replacement ratios of SSF and different SP dosages were tested for segregation width, flowability, L-box passing ability, unit weight and WPD. Results revealed that incorporating an appropriate quantity of SSF and SP improved the WPD of UHWC, resulting in improved segregation resistance, enhanced flowability, increased passing ability and a higher unit weight. Lastly, there is a positive correlation between flowability, passing ability and WPD. [ABSTRACT FROM AUTHOR]

The nuclear radiation shielding materials are having a great importance in reactor shielding, nuclear laboratories, radiation sources storage, as well as in space radiation shielding. The experimental methods are time consuming, facility dependent, as well as costly affair in order to manufacture the shielding materials. The alternative approach is to use nuclear transport codes such as GEANT, MCNP, PHITS, FLUKA for nuclear radiation shielding application. The present work is planned to study the prediction capabilities of transport code for calculation of shielding parameters using two different radiation transport codes and comparison with experimental results. The simulation measurements were carried out by Monte Carlo analysis, 241Am–Be neutron source & neutron dosimeter, and High Density Polyethylene (HDPE) were modeled using MCNP 6 and PHITS 3.22 codes. Subsequently, experimental neutron dose rates were measured after different thickness of HDPE samples using live 241Am–Be neutron source and NRF31 dosimeter. The study shows a good agreement between the experimental and simulated results which suggest that the simulation method can be used for the optimization of new shielding composites. [ABSTRACT FROM AUTHOR]

We study radiative transfer in participating binary stochastic mixtures in two dimensions (2D) by developing an accurate and efficient simulation tool. For two different sets of physical parameters, 2D benchmark results are presented, and it is found that the influence of the stochastic mixture on radiative transfer is clearly parameter-dependent. Our results confirm that previous multidimensional results obtained in different studies are basically consistent, which is interpreted in terms of the relationship between the photon mean free path lp and the system size L. Nonlinear effects, including those due to scattering and radiation–material coupling, are also discussed. To further understand the particle size effect, we employ a dimensionless parameter lp/L, from which a critical particle size can be derived. On the basis of further 2D simulations, we find that an inhomogeneous mix is obtained for lp/L > 0.1. Furthermore, 2D material temperature distributions reveal that self-shielding and particle–particle shielding of radiation occur, and are enhanced when lp/L is increased. Our work is expected to provide benchmark results to verify proposed homogenized models and/or other codes for stochastic radiative transfer in realistic physical scenarios. [ABSTRACT FROM AUTHOR]

Concrete is the favored construction material, with more than 7 billion cubic meters manufactured annually. Aggregates constitute the crucial component of its structure and quality, responsible for its exceptional characteristic features. The characteristics of aggregates determine the mechanical durability and radiation performance of concrete. In this investigation, fabricated concrete specimens were generated by replacing sand and aggregate sizes with pyrophyllite in 10%–20%–30%–100% proportions. The study investigated the mechanical properties of concrete specimens using both pressure and ultrasound methods, as well as their durability under freeze–thaw and high-temperature (200°C–1,000°C) conditions. In addition, the microstructure and radiation permeability properties were examined over a 7–28–90-day period. Notably, the use of pyrophyllite sand and aggregate significantly increased the compressive strength of the specimens by 21%–63% when compared to the reference concrete after 7–28–90 days, while also reducing mass loss by up to 4.6% during freeze–thaw cycles. After subjecting the specimens to high temperatures, it was discovered that those with an air-cooling regime achieved a compressive value 45% higher than the reference concrete. Microstructure images revealed the formation of C─ S─ H, CH, and portlandite hydration products over 90 days, supporting the observed compressive strength values. The study also has an effective linear attenuation coefficient (LAC) for radiation-shielding properties. According to some radiation-shielding parameters calculated through LAC values, it was revealed that these concrete samples were suitable shielding materials. Pyrophyllite-reinforced specimens have demonstrated potential for high-strength concrete production, suitability for use in high-temperature environments, and effectiveness as shielding in areas with radiation sources. [ABSTRACT FROM AUTHOR]

Lead borate glass is the best radiation shielding glass when lead is in high concentration. However, it has low transparency after radiation exposure. Radiation decreases transparency due to chemical and physical changes in the glass matrix, such as creating or healing defects in the glass network. The addition of rare earth elements like cerium and dysprosium oxides to lead borate glasses can improve their transparency and durability as radiation shielding barriers. The newly manufactured glasses' optical absorption, structural, and radiation shielding properties were measured. The optical characteristics of the generated samples were examined to determine the effect of the cerium/dysprosium ratio on the structural alterations, specifically in the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Incorporating Ce3+ results in peaks at 195 nm for borate units, 225 nm for Ce3+, and a broadened peak at 393 nm due to overlapping peaks for Ce3+ and Ce4+ in the UV region. By adding Dy, multiple peaks are observed at 825, 902, 1095, 1275, and 1684 nm, corresponding to the transition from 6H15/2 ground state to 6F5/2, 6F7/2, 6F9/2, 6F11/2, and 6H11/2. The samples were also tested before and after exposure to gamma irradiation from a 60Co source at a dose of 75 kGy to assess their stability against radiation. The energy gap value during irradiation shows decreased non-bridging oxygen. The energy gap difference before and after irradiation for the M4 sample shows higher NBO to BO conversion, reducing radiation damage and improving structural stability. Furthermore, X-ray photoelectron spectroscopy was utilized to get insight into the coordination chemistry of the created glass samples. The half-value layer (HVL), radiation protection efficiency (RPE), neutron removal cross-section (FRNCS), mean free path (MFP), mass attenuation coefficients (MAC), and effective atomic numbers (Zef) of the glassy structure were calculated theoretically to assess its radiation shielding qualities. The linear attenuation coefficient order for the prepared samples was M1 > M2 > M3 > M4. The FRNCS values were 0.090, 0.083, 0.081, and 0.079 cm−1 for samples M1, M2, M3, and M4, respectively. [ABSTRACT FROM AUTHOR]

There are various types of charged particles in the space environment, which can cause different types of radiation damage to materials and devices, leading to on-orbit failures and even accidents for spacecraft. Developing lightweight and efficient radiation-shielding materials is an effective approach to improving the inherent protection of spacecraft. The protective performance of different materials against proton and electron spectra in the Earth's radiation belts is evaluated using a Geant4 simulation. Based on the simulation results, suitable hardening components were selected to design composite materials, and B4C/PEEK composites with different B4C contents were successfully prepared. The experimental results demonstrate that the simulated and experimental results for the electron, proton and neutron shielding performance of the B4C/PEEK composites are consistent. These composites exhibit excellent radiation shielding capabilities against electrons, protons and neutrons, and the radiation protection performance improves with increasing B4C content in the B4C/PEEK composite materials. [ABSTRACT FROM AUTHOR]

The design and preparation of lightweight and flexible electromagnetic interference (EMI) shielding composites with high efficiency and low reflection are critical to the electronic field. First, silver nanowires (AgNWs) were vacuum filtered on the electrospun thermoplastic polyurethane (TPU) fibrous film. Then, by combining the adhesive with the electrospun silicon carbide nanowhisker (SiCnw) @TPU composite fibrous film, the asymmetric EMI shielding composite films with high electromagnetic shielding efficiency (EMI SE) and low incident power were obtained. The lower AgNWs‐TPU layer provides the primary EMI SE, and the upper SiCnw@TPU fibrous film is used for electromagnetic wave absorption. This unique asymmetric structure, the synergistic effect of SiCnw's particular absorbing function and the excellent conductivity of the AgNWs layer make the film show high overall SE (SET = 55.18 dB). In order to improve the absorption effect of the composite film, the number of layers of SiCnw@TPU was adjusted, resulting in a final reflection coefficient value as low as 0.55. This work proposes a new strategy for developing EMI shielding composite films with high efficiency and low reflection, serving as a reference. [ABSTRACT FROM AUTHOR]

A novel polymeric composite was created using polyethylene polymers as the primary component, supplemented with varying weight proportions of micro-sized basalt rock powder. Basalt was incorporated into the base material at concentrations ranging from 20 to 40% by weight. The homogenous distributions of the basalt powder within the epoxy layers were affirmed using the scanning electron microscope (SEM) as well as the FTIR spectra for the fabricated composites were analyzed. The gamma-ray shielding properties for the fabricated composites were examined using the narrow beam transmission method on NaI (Tl) detector. The linear attenuation coefficient measurement shows an enhancement in the linear attenuation coefficient from 0.134 to 0.156 cm−1 by raising the basalt powder ratio from 0 to 40 wt%. These results were associated with an enhancement in the radiation shielding properties of the fabricated composites from 12.6 to 14.2% and the lead equivalent thickness reduced from 9.3to 8 cm by raising the basalt powder concentration from 0 to 40 wt%, respectively. Based on the findings, incorporating micro-sized basalt powder into the epoxy resin improves the gamma-ray shielding capabilities of the produced composites in comparison to various polymers documented in prior studies, especially E-B40. In terms of radiation protection, it can be inferred that E-B40 shows promising potential as a shielding material for gamma rays with low energy, offering increased protection with reduced thickness. [ABSTRACT FROM AUTHOR]

The effect of vanadium oxide (V2O5) on the structural, dielectric, and shielding features of borate-lead-fluoride glasses was investigated. The density of the glass network increased steadily from 3.18 to 3.28 g.cm−3 as the vanadium content increased from 0.0 to 10 mol%. The evolution of functional groups and units such as non-bridging BO3, and bridging BO4, in our newly developed glasses was exposed by FTIR analysis. Since the fraction of bridging units BO4 increases when V2O5 is added up to 2 mol%. This indicates that the conversion of BO3 groups into BO4 groups is facilitated by V2O5. However, at higher concentrations of V2O5 (> 2 mol%), a reversal reaction occurs wherein the BO3 unit fraction increases and the BO4 unit fraction starts to decrease. All the glasses loaded with different amounts of V2O5 mol% had a sharp decline in dielectric constant with increasing frequency over the low frequency interval. As the V2O5 level grew up to 2 mol%, the dielectric constant value was marginally reduced and then increased for higher concentrations. All of the glasses under examination displayed different relaxation peaks in the range of 100 Hz to 20 kHz on their measured loss tangent (tan δ), but vanadium doping caused them to shift to higher frequencies. At 0.015 MeV, the maximum MAC values for the V-0.0 to V-10.0 samples were found to be 29.205 cm2/g to 30.082 cm2/g. In terms of radiation shielding, the V-10.0 sample exhibited the highest values of mass (MAC) and linear (LAC) attenuation coefficients, while the same sample possessed the lowest values of half value layer and mean free path among all investigated glasses. Therefore, the investigate glass can be used in several optical and radiation shielding applications. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the effect of different Bi2O3 contents (45–60 mass %) on the radiation protection ability, mechanical properties, and physical properties of glass samples composed of Bi2O3-SiO2-B2O3-ZnO-Al2O3. To assess these properties, we utilized the Monte Carlo based code MCNPX 2.6.0 and the Phy-X PSD program. We calculated various mechanical and physical values, including the elastic modulus, Poisson's ratio (σ), and Fractal Bond Connectivity. The radiation shielding properties of various glass compositions were investigated for a range of photon energies including 0.284, 0.347, 0.511, 0.662, 0.826, and 1.173 MeV. The study found that glass compositions with minimal mole fraction of B2O3 exhibited higher density, Equivalent Atomic Number (Zeq), Effective Atomic Number (Zeff), Molar Oxygen Volume, and lower Half Value Layer (HVL), Tenth Value Layer (TVL), Mean Free Path (MFP), and Oxygen Packing Density. Based on these findings, it can be concluded that the glass composition containing 60Bi is the most effective γ-ray attenuator and is recommended as the best glass for this purpose. [ABSTRACT FROM AUTHOR]

Gamma‐ray, fast neutron and charged particle shielding characteristics of Praseodymium (Pr3+) activated glasses with composition 10ZnF2‐(10‐x)SrO‐15Li2O‐65H3BO3‐xPr2O3(where x = 0.1, 0.5, 1.0, 1.5, and 2.0) are investigated. For this, the radiation shielding parameters are estimated by using Photon Shielding and Dosimetry (Phy‐X/PSD), Interaction of Proton, Alpha, Gamma rays, Electrons, and X‐rays with matter (PAGEX), Stopping Powers and Ranges for Electrons (ESTAR), and The Stopping and Range of Ions in Matter (SRIM) codes. Furthermore, the results are compared comprehensively and comparatively. The glasses with increasing Pr3+ content exhibited higher shielding potential. It can be said that the ZFLHBPr2.0 sample could be used as a shielding material in various applied fields. Additionally, the effect of Pr composition on structural transitions and time‐dependent volume‐collapse of this new family of borate glass doped with Pr is analyzed by molecular dynamics study (MD) based density functional tight binding method. The simulation results show that the addition of Pr led to the cubic‐orthorhombic transformation of simulation cell at determined temperature and 1 atm pressure. Also, a sudden decrease in volume are observed within a short time at 8% Pr composition (x = 2.0) atmospheric pressure. This result provides a strong connection between Pr composition and volume change with time and at constant low pressure. [ABSTRACT FROM AUTHOR]

Polymers play an essential role in both industry and medical fields due to their diverse and adaptable properties. In this work, prepared crosslinking polyethylene (XLPE) samples with hydrophilic bentonite nanoclay fillers (H2Al2O6Si) at concentrations of 0, 1, 2.5, 4, and 5 wt% enhance their flame-retardant and radiation shielding efficiency. The research investigated flame retardancy and thermal stability parameters. The XLPE/H2Al2O6Si nanocomposite polymer sheets were exposed to a collimated beam of fast neutrons using an Am/Be neutron source (5 Ci) and to gamma radiation using a 137Cs point source (5 μCi) to assess their radiation shielding properties. The study found that uniform dispersion of nanoclay particles enhanced the thermal properties of the composite, forming a char layer that acted as a barrier, slowing thermal decomposition and reducing the heat release rate. Limiting oxygen index (LOI) increased from 28% to 34%, and burning rate improved with higher nanoclay concentrations. Additionally, absorption and optical band gap calculations decreased with increasing filler concentrations. Radiation attenuation capabilities increased by approximately 40% for neutrons and 30% for gamma radiation compared to pure XLPE. The study concluded that incorporating nanoclay fillers into XLPE enhances its shielding capabilities and improves flame resistance properties, making the prepared samples suitable for various industrial applications. [ABSTRACT FROM AUTHOR]

This study investigates the gamma-ray attenuation capabilities of ABS polymer reinforced with nano-sized yttrium particles. The analysis focuses on three key parameters: mass attenuation coefficient, half-value layer, and radiation protection efficiency. Utilizing a sol–gel process for polymer molding, various test samples were prepared and subjected to scanning electron microscopy (SEM) for surface structure examination. Then, experimental, theoretical, and simulation approaches are used to obtain gamma-ray shielding parameters. The base and additive materials are chosen as ABS polymer and yttrium nanoparticles, respectively, and the results revealed a consistent enhancement in gamma-ray attenuation characteristics with the incorporation of yttrium nanoparticles. These findings offer valuable perspectives for advancing the development of sophisticated radiation shielding materials, presenting potential applications across diverse fields including medical imaging, industrial processes, and nuclear technologies. [ABSTRACT FROM AUTHOR]

With the wide use of radioactive materials, it is important to look for locally available and inexpensive materials to serve as efficient absorbers, suitable for shielding against radiation hazards. Due to its widespread availability and affordability, natural bentonitic shale is a viable option for use as a nuclear shielding material. In this study, natural bentonitic samples were cut into cylindrical pellets of varying thicknesses. The chemical composition of the natural bentonitic shale samples was determined through the use of X-Ray Fluorescence (XRF) spectroscopy. The linear and mass attenuation coefficients of bentonitic samples were evaluated using a NaI(Tl) scintillation detector at 662 keV energy of 137Cs, as well as at 1,173 keV and 1,332 keV energies of 60Co, gamma-ray sources. The experimental results indicated that bentonitic samples B3 and M2 exhibited superior shielding parameters compared to other bentonitic samples, attributable to their elevated densities. These two samples are distinguished by a high CaO content and a low AL2O3 content. Furthermore, the Half Value Layer (HVL), Tenth Value Layer (TVL), and mean free path thicknesses were calculated at these energies using linear attenuation coefficients. The theoretical mass attenuation coefficient, calculated with the assistance of the XCOM program and experimental estimates, was found to be in good agreement with the theoretical value. [ABSTRACT FROM AUTHOR]

Fluoroboro tellurite glasses containing La2O3 with nominal composition of 43B2O3 + 33TeO2 + (12−x)BaF2 + 12Na2O + xLa2O3x = 0 (La0.0), 0.5 (La0.5), 1 (La1.0), 2 (La2.0), and 3 (La3.0) mol% were fabricated using the melt quenching technique. The effects of La3+ ion content inclusion in the prepared glass matrices, including the structural, physical, and optical properties and γ-ray protection efficacy, were then explored. The amorphous state of the La-glasses was verified by the broad and diffuse dispersion of all XRD patterns at low angles. As La2O3 additives were added from 0 to 3 mol%, the density (ρ) increased from 3.6243 g/cm3 to3.8743 g/cm3 and the molar volume (Vm) decreased from 30.6488 cm3/mol to 29.8364 cm3/mol. Lanthanum ion concentrations (NLa) increased from 0 for La0.0 glasses to 312.1103 × 1020 cm−3 for La3.0 glasses. The polar radius decreased from 0 Å to 3.7813 Å, whereas the ligand field strength between La ions and their surroundings increased from 0 Å−2 to 18.1839 Å−2. Values of optical gap (Eg) varied from 3.07 eV to 2.82 eV. The values of linear refractive index (n0) varied from 2.383 to 2.443, whereas values of nonlinear refractive index (n2) changed from 5.16 × 10−11 esu to 6.40 × 10−11 esu for La0.0 and La3.0 glass specimens. Mass (MAC) and linear (LAC) attenuation coefficients were lowest in La0.0 glasses and highest in La3.0 glasses. The trend of the mean free path (MFP) of La-glasses was inverse to that of the LAC and MAC. The order of the MFP trend, which indicates the influence of La2O3 in the glass matrix, was typically (MFP)La0.0 > (MFP)La0.5 > (MFP)La1.0 > (MFP)La2.0 > (MFP)La3.0. Results show that the recommended glasses appear to be promising materials for various optical devices and radiation protection applications. [ABSTRACT FROM AUTHOR]

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This study investigates the individual and combined effects of enhancing the radiation shielding properties of waste concrete using the optimal mix design of two waste material powders of different compositions. Marble (MD) and granite (GD) waste dust were individually utilized as partial replacements for cement at a replacement ratio of 6%. Furthermore, two additional mixes were prepared by incorporating 1% by cement weight of nano alumina (NA) to enhance the microstructure of the studied waste concrete. The MGA-concrete was analyzed using X-ray Fluorescence, Energy dispersive X-ray, X-ray diffraction analysis, transmission electron microscopy, and scanning electron microscope techniques. The radiation shielding assets of the examined Concrete samples, such as the linear attenuation coefficient (μ), half value layer (H1/2), tenth value layer (T1/10), and fast neutron removal cross-section were evaluated using the MCS5 Monte Carlo simulation algorithm and Phy-X software. The results showed that the linear attenuation for the GMN-concretes' order is CO < MD < GD < NA < MD + NA < GD + NA. The GD + Na concrete sample presents the best neutron performance. The studied GMN-concrete samples provide the best protection against γ-rays and fast neutrons. Lastly, the excellent performance of the mixes of waste Granite, Marble, and Nano-Alumina on ordinary would pave the way for their employment as radiation shielding in various nuclear and medical facilities. [ABSTRACT FROM AUTHOR]

This work uses pure polyvinyl chloride (PVC) with magnesium oxide (MgO) nanoparticles to enhance PVC's optical and shielding properties. The distribution of MgO nanoparticles in the PVC polymer was shown using a scanning electronic microscope, x‐ray diffraction, and Fourier transform infrared. The prepared samples' optical parameters and thermal analysis are investigated using ultraviolet (UV) spectroscopy and thermogravimetric analysis, respectively. The shielding characteristics parameters for the prepared samples were experimentally tested using a Cs‐137 point source with an energy of 0.662 MeV, and the outcomes were contrasted with what the XCOM software had calculated. Results indicated that optical constants were significantly affected by the addition of MgO wt% concentration. The linear attenuation coefficient was directly proportional to the weight concentration of MgO nanoparticle filler in the PVC matrix, and the ability to absorb UV increased. Adding MgO nanoparticle concentrations improved the PVC composite's radiation shielding behavior. It concluded that the PVC/MgO nanoparticle‐prepared samples are suitable for packaging for industrial applications and apron shielding for medical applications. [ABSTRACT FROM AUTHOR]

13C and 1H NMR spectra were observed as the function of density in 1,2-13C-enriched ethane and ethylene for the pure gaseous compounds and their binary mixtures with xenon and carbon dioxide gases as the solvents. All the chemical shifts and indirect spin–spin couplings were linearly dependent on the solvent density. The appropriate NMR parameters (σ and nJ) in isolated 13C2H6 and 13C2H4 molecules and the coefficients responsible for the binary molecular interactions were determined and compared with previous similar measurements and selected calculated shielding data. The newly obtained 13C shielding values in the isolated ethane and ethylene molecules suggest visible secondary isotope effects due to the additional carbon-13 atom. All the investigated shielding parameters depend on intermolecular interactions, and the dependence of 13C shielding is much more marked. In contrast, the indirect spin–spin couplings in 13C2H6 and 13C2H4 molecules are almost independent of solvent molecules. Their nJ values determined in liquids over sixty years ago are generally consistent with the same nJ parameters in isolated 13C2H6 and 13C2H4 molecules. [ABSTRACT FROM AUTHOR]

Caffeine is an alkaloid with a purine structure and has been well known for centuries due to its presence in popular drinks—tea and coffee. However, the structural and spectroscopic parameters of this compound, as well as its chemical and biological activities, are still not fully known. In this study, for the first time, we report on the measured oxygen-17 NMR spectra of this stimulant. To support the assignment of our experimental NMR data, extensive quantum chemical calculations of NMR parameters, including nuclear magnetic shielding constants and indirect spin–spin coupling constants, were performed. In a theoretical study, using nine efficient density functionals (B3LYP, BLYP, BP86, CAM-B3LYP, LC-BLYP, M06, PBE0, TPSSh, wB97x), and in combination with a large and flexible correlation-consistent aug-cc-pVTZ basis set, the structure and NMR parameters were predicted for a free molecule of caffeine and in chloroform, DMSO and water. A polarized continuum model (PCM) was used to include a solvent effect. As a result, an optimal methodology was developed for predicting reliable NMR data, suitable for studies of known, as well as newly discovered, purines and similar alkaloids. The results of the current work could be used in future basic and applied studies, including NMR identification and intermolecular interactions of caffeine in various raw materials, like plants and food, as well as in the structural and spectroscopic characterization of new compounds with similar structures. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) have attracted significant attention from researchers in academia and industry due to their various applications. They are effectively utilized in the manufacturing industry and find extensive use in nuclear technology to enhance radiation shielding properties. In this research article, a novel alloy composition called Co20Cr20Fe20Ni20Ag20 was fabricated using the mechanical milling process. Several characterization methods, such as Scanning and Transmission Electron Microscopy, Energy-Dispersive Spectroscopy, x-Ray Diffraction, and Differential Thermal Analysis Calorimetry, were employed. It was observed that the crystal size decreased as the alloying time increased, and the synthesized alloy exhibited thermal stability across a wide temperature range. Additionally, radiation shielding parameters were experimentally determined using a 137Cs source and a NaI(Tl) detector system. The obtained results indicate that HEAs possess excellent radiation shielding properties and hold promise for applications in the radiation industry. [ABSTRACT FROM AUTHOR]

To ensure the safety of medical personnel in healthcare organizations, radiation-shielding materials like protective clothing are used to protect against low-dose radiation, such as scattered rays. The extremities, particularly the hands, are the most exposed to radiation. New materials that can be directly coated onto the skin would be more cost-effective, efficient, and convenient than gloves. We developed protective creams using eco-friendly shielding materials, including barium sulfate, bismuth oxide, and ytterbium oxide, to avoid harmful effects of heavy metals like lead, and tested their skin-protective effects. Particularly, the radiation-shielding effect of ytterbium oxide was compared with that of the other materials. As shielding material dispersion and layer thickness greatly affect the efficacy of radiation-shielding creams, we assessed dispersion in terms of the weight percentage (wt%). The effective radiation energy was reduced by 20% with a 1.0-mm increase in cream thickness. Ytterbium oxide had a higher radiation-shielding rate than the other two materials. A 28% difference in protective effect was observed with varying wt%, and the 45 wt% cream at 63.4 keV radiation achieved a 61.3% reduction rate. Higher content led to a more stable incident energy-reducing effect. In conclusion, ytterbium oxide shows potential as a radiation-shielding material for creams. [ABSTRACT FROM AUTHOR]

A novel methodology is introduced to asses the efficacy of cosmic radiation shielding through the fabrication of electrospun nanocomposite fiber mats reinforced with hexagonal boron nitride (h‐BN) and carbon nanotubes (CNTs). These mats were fabricated using various h‐BN particles synthesized with 1 M boric acid and four distinct 1 M nitrogen sources to produce polyethylene oxide (PEO) nanofibers via the electrospinning method at 15 kV, a 43.0 μL/min pumping rate, and a 20 cm distance with a maximum thickness of 10 μm. High neutron shielding capability nanocomposite fibers denoted BN‐F4 (spun with h‐BN [melamine]/CNT powders in a 5 wt% PEO solution) and BN‐F5 (spun with h‐BN [urea]/CNT powders in a 5 wt% PEO solution) were produced. By calculating the theoretical photon transmittance and evaluating the neutron shielding efficiency with an Am‐Be neutron source and a BF3 neutron detector, the cosmic radiation shielding capability of nanocomposite mats was discussed. BN‐F4 and BN‐F5 exhibited neutron shielding properties of 7.124% and 6.37% for 3.82 and 1.87 g/mL, respectively. This research establishes a new benchmark in the fabrication of flexible, ultrathin, and lightweight radiation shielding materials and enhances the practicality of nanocomposites reinforced with h‐BN and CNTs by incorporating synthesizing and characterizing steps. Highlights: In the study, hexagonal boron nitride production was carried out with four different nitrogen sources and which one showed better structural and morphological properties was supported by analysis.Additionally, an optimization study of nanofibers by electrospinning by adding CNT and h‐BN particles with PEO polymer is included.It is thought that the production of h‐BN and nanofiber work as a radiation shielding feature for use in space studies will be innovative and contribute to the deficiency in the literature. [ABSTRACT FROM AUTHOR]

Multilayer polymers have potential applications in various fields for radiation shielding. It is quite interesting to investigate the shielding properties of polymer composites in a combined manner. In the present investigations, the high-z-doped PVA polymers such as PVA+50% Bi2O3 and PVA+50% Na2O4W were selected, and the multilayer buildup factors were calculated for various combinations of high-z-doped multilayer PVA polymers using the Py-MLBUF software. The PVA+50% Bi2O3 and PVA+50%Na2O4W are coded, respectively, as A and B. The BA and BBA combinations have the potential to replace a single layer of high-z-doped PVA polymers, and these combinations can be used as gamma-ray shields. [ABSTRACT FROM AUTHOR]

When interacting with absorption materials, beta rays, which are emitted by isotopes, are harmful because bremsstrahlung (braking) radiation is produced. Therefore, the efficiency of a shielding material can be improved by considering the bremsstrahlung radiation generated by the material's beta ray absorption. In this study, to determine the risk of bremsstrahlung radiation produced by beta rays, the fractions of beta energy transformed into bremsstrahlung radiation were calculated for beta emitters in the energy ranges of 0.0026-0.1734, 0.205-0.694, and 0.9345-2.640 MeV, using five different absorption materials (13Al, 26Fe, 48Cd, 74W, and 82Pb). The relationship between the fractions of beta energy transformed into bremsstrahlung radiation by the five shielding materials and the maximum energies of some beta emitters was studied to determine the most suitable beta-ray shielding materials to effectively minimize bremsstrahlung radiation. The results showed that the fractions of beta energy transformed into bremsstrahlung radiation increased as the beta energy and the atomic number of the shielding material increased. The fraction of beta energy transformed into bremsstrahlung radiation in 13Al < 26Fe < 48Cd < 74W < 82Pb. Therefore, beta ray shields should be made with low atomic number materials to reduce the generation of bremsstrahlung radiation. Practically, beta shields made from materials with atomic numbers greater than 13 are rarely employed; notably, aluminum successfully decreased the production of bremsstrahlung radiation. However, it is also necessary to use materials with medium and high atomic numbers as secondary beta shields to reduce the effect of the bremsstrahlung radiation photons formed by the interaction between beta rays and shielding materials. [ABSTRACT FROM AUTHOR]

In radiology it is necessary to use protective devices in radiological work to reduce the negative health effects of radiation. The objective of this study is to investigate an alternative lead-free radiation shielding material from PLA composite with BaSO4 and assess its efficacy in providing radiation protection. The findings indicate that the PLA composite containing 30% BaSO4 exhibited the most effective radiation absorption properties, with percentages of 92.15%, 89.26%, and 86.04% at X-ray energies of 40, 60, and 80 kVp, respectively. Moreover, the PLA composites containing BaSO4 are environmentally friendly providing suitable protection against low-dose radiation [ABSTRACT FROM AUTHOR]

This study explores the gamma-ray and neutron transmission properties of β-Titanium alloys pivotal for their performance in nuclear and biomedical applications. Utilizing the Monte Carlo N-Particle (MCNP 6.3) simulations, we analyzed a spectrum of Ti-based alloys modified with elements like molybdenum (Mo), zirconium (Zr), niobium (Nb), and hafnium (Hf) to determine their radiation attenuation properties. Key parameters such as mass and linear attenuation coefficients, half-value layers, exposure buildup factors, and fast neutron effective removal cross-section values were computed, revealing significant enhancements in attenuation with the addition of high-Z elements. Specifically, alloys like Ti50Hf50 and (TiZr)40Cu60 exhibited superior photon and fast neutron attenuation due to their high-Z constituents. For instance, Ti50Hf50 showed a mass attenuation coefficient of 0.217 cm2/g and a half-value layer of 2.97 cm at 0.1 MeV photon energy, while (TiZr)40Cu60 demonstrated similar performance with a mass attenuation coefficient of 0.198 cm2/g and a half-value layer of 3.26 cm. These alloys also exhibited effective neutron removal cross-section values of 0.115 cm−1 and 0.130 cm−1, respectively. Alloys with lower-Z elements showed less attenuation, which may be beneficial in scenarios requiring reduced radiographic contrast in biomedical applications. The MCNP outcomes were in strong agreement with standard data, affirming the accuracy of computational methods in predicting material behavior. In conclusion, tailored alloy development is crucial for improving radiation shielding and diagnostic visualization, with broader implications for patient safety and treatment efficacy. [ABSTRACT FROM AUTHOR]

In recent decades, the opportunity to introduce self-healing materials within space structures has drawn the attention of scientists and companies. Autonomous repair following damage caused by impacts with micrometeoroids and orbital debris (MMOD) would lead to safer human activity in space and would increase spacecraft operational life and autonomy, thus reducing replacement costs and possibly relieving astronauts from maintenance activities. In particular, integrating self-healing materials into structures to protect humans from the space environment is a fundamental step in the realization of long-lasting space exploration missions. Nevertheless, the way these materials interact with the environmental factors in space still needs to be properly analyzed and understood; in particular, space radiation is a serious threat to human health and material integrity. The proposed work hence investigates the shielding ability of candidate self-healing materials with the specific purpose of human protection in crewed missions. The NASA HZETRN2015 (High Z and Energy TRaNsport, 2015 version) software is used to simulate galactic cosmic rays (GCR) and low Earth orbit (LEO) environment. A comparison between a standard habitat layup proposed by NASA and a set of configurations containing self-healing polymers is performed to verify that the substitution of conventional bladder materials with the proposed self-healing solutions does not decrease the overall habitat shielding performance. A self-healing nanocomposite option with single-walled carbon nanotubes (SWCNTs) is also analyzed to determine whether the insertion of nanofillers can increase the overall shielding performance. In the second phase, the comparison of puncture tests on blank and irradiated samples under conditions reproducing a space suit example is presented to assess the possible effects of radiation on the self-healing performance. [ABSTRACT FROM AUTHOR]

As the availability and importance of high energy X-ray sources grows, accurate source characterizations provide critical information for field flatness corrections, beam hardening corrections, detector response corrections, and radiation shielding assessments. This study uses MCNP6.2 to create accurate high definition angular and energy dependent X-ray source definitions for the most common high energy industrial X-ray sources at 450 kVp, 3 MVp, 6 MVp, 9 MVp, and 15 MVp. [ABSTRACT FROM AUTHOR]

The radiation shielding properties of different samples of borate-tellurite glass were investigated using WO3 modifiers. Geometric optimization and modification of pristine borate-tellurite with WO3 were carried out based on density functional theory calculations using plane wave basis sets and pseudo-potentials. It was observed that the changes in the physical properties of the white box testing glass (WBTG) systems were determined by WO3 content. Analysis of the linear attenuation coefficient of the sampled glasses, which yielded a value of 7.43 cm for WBTG1 at 20 keV, indicated that WBTG1 was able to stop gamma radiation from Cs-137 and Th-237 sources. Both the µ and µm values were zero above 0.15 MeV, indicating that the WBTG composite was only able to attenuate low-energy photons such as gamma rays. It was found that the characteristic behavior of the WBTG was generally determined primarily by oxygen content, which is in good agreement with theoretical and experimental data. [ABSTRACT FROM AUTHOR]

Within the field of radiology, safeguarding against radiation is crucial, particularly in diagnostic procedures like X-rays, as radiation exposure holds the potential to harm cellular DNA. Presently, lead serves as the predominant material for radiation shielding. However, its usage raises environmental concerns owing to its toxic properties. The objective of this study is to investigate a radiation shielding alternative to lead and assess its efficacy in protecting against radiation. We examined the radiation absorption properties of material made from a composite of PBS and iodine contrast media in various proportions. Our findings indicate that the shielding material containing 75% iodine have the greatest ability to reduce radiation dose from X-rays but are still less than lead. Moreover, the PBS composite with iodine contrast media proved to be environmentally friendly, flexible, and exhibited excellent shielding performance in mitigating exposure during diagnostic X-ray procedures. [ABSTRACT FROM AUTHOR]

Background: An ultra‐high dose rate (UHDR) electron accelerator for FLASH radiotherapy (RT) produces very intense bremsstrahlung by the interaction of the electron beam with objects both inside and outside of the accelerator. The bremsstrahlung dose per pulse is typically 1–2 orders of magnitude larger than that of conventional RT x‐ray treatment of the same energy, and for electron energies above 10 MeV, the bremsstrahlung produces substantially more induced radioactivity outside the accelerator than for conventional RT. Therefore, a thorough radiation safety assessment is mandatory prior to the operation of a UHDR electron accelerator. Purpose: To evaluate the radiation safety of a prototype FLASH‐enabled Varian TrueBeam accelerator and to develop a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator for FLASH RT. Methods: Production of bremsstrahlung and induced radioactivity by a UHDR electron accelerator is modeled by various analytical methods. The analytical modeling is compared with National Institute of Standards and Technology (NIST) bremsstrahlung yield data as well as measurements of primary bremsstrahlung outside the bunker and induced radioactivity of irradiated thick targets for a FLASH‐enabled 16 MeV Varian TrueBeam electron accelerator. In addition, the analytical modeling is complemented by measurements of secondary bremsstrahlung inside/outside the bunker and neutrons at the maze entrance. Results: Calculated bremsstrahlung yields deviate maximum 8.5% from NIST data, and all measurements of primary bremsstrahlung and induced radioactivity agree with calculations, validating the analytical tools. In addition, it is found that scattering foil bremsstrahlung dominates primary bremsstrahlung and the main source of secondary bremsstrahlung is the irradiated object outside the accelerator. It follows that primary and secondary bremsstrahlung outside the bunker can be calculated using the same simple formalism as that used for conventional RT. Measured primary bremsstrahlung tenth‐value layers for concrete of the simple formalism are in good agreement with NCRP and IAEA data, while measured secondary bremsstrahlung tenth‐value layers for concrete are considerably lower than NCRP and IAEA data. All calculations and measurements form a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator. Conclusions: The FLASH‐enabled Varian TrueBeam accelerator is safe for normal operation (max. 99 pulses per irradiation) in a bunker designed for at least 15 MV conventional x‐ray treatment unless the UHDR workload is much larger than the x‐ray workload. A similar finding applies to other UHDR electron accelerators. However, during beam tuning, radiation survey, or other tests with extended irradiation time, the UHDR workload may become very large, necessitating the implementation of additional safety measures. [ABSTRACT FROM AUTHOR]

In this work, tungsten oxide (WO3) particles (in micro and nanoscales) have been mixed with silicon epoxy resin to create a novel composite to enhance the radiation attenuation properties of an epoxy resin shield. Six epoxy resin samples were created using various WO3 micro/nanoparticles concentrations. Several radioactive sources with varying energies were employed along with a high-purity germanium detector to evaluate the prepared samples' shielding capabilities. The linear attenuation coefficients (LACs) were measured experimentally using the narrow beam method. Based on the experimentally obtained values of LACs, other radiation shielding parameters, including half value length (HVL), tenth value layer (TVL), radiation shielding efficiency (RSE), and mean free path (MFP), were computed. The EW-20m30n sample (50% epoxy + 20% micro WO3 + 30% nano WO3) had the lowest MFP, HVL, and TVL at any given energy. Thus, in terms of material thickness, the EW-20m30n sample offers the best shielding characteristics. Furthermore, because of its superior density, the almost even mixture of nanoparticles and microparticles in the EW-20m30n sample produces a RSE of ≅ 100% in the low energy zone. Conversely, it was found that the samples' ability to protect decreased as the energy increased. Calculating HVL, TVL, and MFP revealed a high energy dependence that grew as the incident photon energy rose. On the other hand, for 50% micro WO3 and 50% epoxy, the EW-50m sample had the least ideal shielding characteristics. Categorically, our study has demonstrated that adding WO3 micro/nanoparticles to epoxy resin polymer has improved the polymer's radiation shielding properties. [ABSTRACT FROM AUTHOR]

This study focuses on how the chemical makeup of the glass' basic components affects the glass' structure and optical characteristics. Four glass samples have been created for this purpose using the chemical formula; 94 mol% Na2B4O7—(6-x) mol% CeO2 – x mol% Ce(NO3)3, where 0 ≤ x ≤ 6. The Ce cations in this formula have two separate chemical sources, CeO2 and Ce(NO3)3, with CeO2 eventually being replaced by Ce(NO3)3. The standard melt-quenching technique was used to prepare the studied glasses. While X-ray direction (XRD), differential scanning calorimetry (DSC), and UV–vis were used for the structural and optical characterizations. XRD patterns revealed the short-range order glass networks for the prepared samples, while DSC thermograms showed that when CeO2 was replaced with Ce(NO3)3, the glass transition temperature (Tg) decreased, causing the glass stability to improve. The optical characterization resulted in the finding that when CeO2 was replaced with Ce(NO3)3, the Urbach's energy increased with a decrease in bandgap energies, which reflects an increase in the glass homogeneity. Finally, the results may imply that Ce(NO3)3-based glasses can be proposed for usage in applications for UV blockers, radiation shielding, light attenuation, and n-type semiconductors. [ABSTRACT FROM AUTHOR]

Achieving lead-free flexible materials with excellent γ-ray shielding as well as good mechanical properties are of significance to radiation protection safety and wear comfort of wearable articles. In this paper, polydopamine (PDA) is coated on Bi2O3 particles to form a typical core–shell structure Bi2O3@PDA, which is used to intensely bond bismuth oxide (Bi2O3) with chloroprene rubber (CR). It promotes the interface interaction between Bi2O3 and CR matrix, leading to the uniform dispersion of the filler and rich interfacial compatibility in CR/Bi2O3@PDA composite with as high as 50 wt% filling. Furthermore, 50 wt% CR/Bi2O3@PDA composite displays 53.6% shielding rate for 105 keV γ-rays. Meanwhile, its tensile strength and elongation at break are 9.6 MPa and 1424.8%, respectively, which are without sacrificing too much in comparison with the neat rubber. We propose a versatile route to prepare superior integrated properties of flexible materials, which can be used as wearable articles for radiation shielding. [ABSTRACT FROM AUTHOR]