Experimental study of gamma-ray attenuation capability of B2O3-ZnO-Na2O-Fe2O3 glass system.

In the present work, a glass system with developed composition consisting of B2O3, ZnO, Na2O and Fe2O3 samples has been investigated. Glass samples were prepared using the melt quenching method and the density of the system was measured using Archimedes' principle. Spectroscopic analysis using a gamma source and a high-purity germanium detector at four energies of 0.0595, 0.6617, 1.173, and 1.333 MeV emitted from Am-241, Cs-137, and Co-60 were used to determine the attenuation parameters of present glass composites. The sample containing 45 B2O3 + 10 Na2O + 40 ZnO + 5 Fe2O3 (coded BNZF-4) had the highest mass attenuation coefficient (MAC) value at all the energies discussed compared to the other composites. Whoever, the BNZF-1 sample had the lowest value at all ranges of energies. The transmission factors (TF, %) of the manufactured samples were calculated, at 0.0595 MeV (TF, %) values are 32.6429 and 6.4612 for samples BNZF-1 and BNZF-4, respectively. The statistical results demonstrated significantly better to increase the ZnO concentration in the sample, where the percentage of zinc oxide inside the prepared glass samples has the following direction BNZF -4 > BNZF -3 > BNZF -2 > BNZF -1. The significance of this study is that transparent, environmentally harmless glass composites with relatively high density have been prepared that can be used as shielding materials against gamma rays, especially at low energies.

Effect of Bi2O3 Particle Size on the Radiation-Shielding Performance of Free-Lead Epoxide Materials against Ionizing Radiation.

In this work, we studied the effect of bismuth oxide particle size and its attenuation capacity as a filler additive in epoxy resins. Six samples were prepared according to the amount of microparticles and nanoparticles in the sample and were coded as ERB-1, ERB-2, ERB-3, ERB-4, ERB-5, and ERB-6. One of the composite epoxies contained Bi2O3 microparticles at a 50:50 ratio (ERB-6) and was chosen as the control composite, and the number of microparticles (MPs) was gradually decreased and replaced by nanoparticles (NPs) to produce epoxy-containing Bi2O3 nanoparticles at a 50:50 ratio (ERB-1). The morphological and thermal characteristics of the studied composites were tested. The attenuation capability of the prepared composites, which is determined by the Bi2O3 particle size, was determined experimentally using a semiconductor detector, an HPGe-detector, and three different gamma-ray point sources (Am-241, Co-60, and Cs-137). The linear attenuation coefficient (LAC) of ERB-3, which contained 30% nanoparticles and 20% microparticles, had the highest value compared to the other composites at all the energies discussed, while the ERB-6 composite had the lowest value at all energies. The radiation-shielding efficiency (RSE) of the prepared samples was determined at all discussed energies; at 662 keV, the radiation-shielding efficiency values were 15.97%, 13.94%, and 12.55% for ERB-3, ERB-1, and ERB-6, respectively. The statistics also proved that the attenuation capacities of the samples containing a combination of nanoparticles and microparticles were much superior to those of the samples containing only microparticles or nanoparticles. A ranking of the samples based on their attenuation capacity is as follows: ERB-3 > ERB-4 > ERB-2 > ERB-1 > ERB-5 > ERB-6.

Design and Computational Validation of γ-Ray Shielding Effectiveness in Heavy Metal/Rare Earth Oxide-Natural Rubber Composites.

This study involved the preparation of natural rubber-based composites incorporating varying proportions of heavy metals and rare earth oxides (Sm2O3, Ta2O5, and Bi2O3). The investigation analyzed several parameters of the samples, including mass attenuation coefficients (general, photoelectric absorption, and scattering), linear attenuation coefficients (µ), half-value layers (HVLs), tenth-value layers (TVLs), mean free paths (MFPs), and radiation protection efficiencies (RPEs), utilizing the Monte Carlo simulation software Geant4 and the WinXCom database across a gamma-ray energy spectrum of 40-150 keV. The study also compared the computational discrepancies among these measurements. Compared to rubber composites doped with single-component fillers, multi-component mixed shielding materials significantly mitigate the shielding deficiencies observed with single-component materials, thereby broadening the γ-ray energy spectrum for which the composites provide effective shielding. Subsequently, the simulation outcomes were juxtaposed with experimental data derived from a 133Ba (80 keV) γ-source. The findings reveal that the simulated results align closely with the experimental observations. When compared to the WinXCom database, the Geant4 software demonstrates superior accuracy in deriving radiation shielding parameters and notably enhances experimental efficiency.

Comprehensive study for radiation shielding features for Bi2O3-B2O3-ZnO composite using computational radioanalytical Phy-X/PSD, MCNP5, and SRIM software.

The current study uses zinc oxide doping nanoparticles to investigate the radiation shielding properties of bismuth borate glass. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) examined the structural characteristics of the current samples. In contrast, the optical properties were determined based on the absorption spectrum for current samples. Appraisal studies are carried out depending on the simulation capabilities of Phy-X/PSD software in conjunction with MCNP5 to achieve this goal. In addition, the neutron and charged particle shielding properties were evaluated theoretically. All glasses are amorphous, as confirmed by the XRD data, and the FTIR data showed several vibration bands and functional groups. The density showed rising from 5.981 to 6.433 g/cm3 with adding ZnO. The band gap values reduced from 2.831 to 2.091 eV for direct and 3.024 to 2.218 eV for indirect with adding ZnO. The investigations' findings demonstrate a strong agreement between the theoretical and simulation-derived estimates of the mass attenuation coefficient. The relative difference of MAC results lie in the range 0.106-2.941% for BBZ0, 0.105-4.348% for BBZ1, 0.105-3.398% for BBZ2, and 0.105-2.032% for BBZ3. The study's findings are valuable insights from thoroughly examining these parameters, which can potentially improve the radiation protection abilities of Bi2O3-B2O3-ZnO glasses. This study represents a significant step in developing more efficient and safer materials for gamma radiation shielding applications.

Investigation of nano MgO loaded polyvinyl chloride polymer in protective clothing as a nonlead materials.

Recently, investigation of advanced shielding materials to be used as an alternative to lead apron has become important. In the current study, MgO loaded into PVC matrix as a non-lead modern shielding composite was modeled to evaluate its performance on radiation protective clothing (RPC). Parameters such as mass attenuation coefficient (MAC), mean free path (MFP), flux buildup factor (FBF), transmission factor (TF) and lead equivalent value (LEV) of samples were calculated using MCNPX Code. The simulation of the MCNP code was validated, by comparing the mass attenuation of concrete sample, with standard XCOM data and very good agreement was attended between XCOM and MC Code results. The MAC of nano and micro-sized samples were also compared with pure PVC and it was found that the nano MgO particle exhibits higher attenuation compared to micro MgO particle and pure PVC. The results show that, the MAC of samples increased to 63.13 % in 1.332 MeV with increasing filler concentration of nano MgO to 50 wt% relative to pure PVC. Investigation of LEV shows that nano MgO sample has more effective than Pb in 1.173 and 1.332 MeV gamma ray energy so that it provides 36.46 % and 11.13 % lighter RPC than Pb ones.

Newly developed CeO2 and Gd2O3-reinforced borosilicate glasses from municipal waste ash and their optical, structural, and gamma-ray shielding properties.

From the useless municipal solid waste (MSW) ashes, CeO2, Gd2O3 and CeO2 + Gd2O3 doped borosilicate glasses were organized via melting-quenching procedure. Various optical, structural, physical and radiation shielding parameters were examined towards the influence of 100 kGy of γ-radiation. UV-visible NIR spectra revealed UV peaks at 351, 348 and 370 nm corresponding to the trivalent states of Ce3+ and Gd3+ ions, while, photoluminescence (PL) spectra displayed asymmetric broad excitations of Ce3+ and Gd3+ ions due to 4f → 5d transitions, and emission intense bands at 412, 434, and 417 nm. CIE chromaticity shows that Gd3+ ions increase the luminescence of Ce3+. FTIR absorption bands revealed an overlapping between tetrahedral groups of silicate (SiO4), with trigonal (BO3) and tetrahedral (BO4) units of borate. The influence of 100 kGy obtains quite reduction in UV-visible NIR and PL peaks, large stability in FTIR and ESR spectra, and stability of thermal expansion coefficient (CTE) as well. The whole data revealed optical, structural and physical stability of glasses after irradiation besides an enhancement in microhardness owing to more structural compactness and high bonding connectivity. Radiation shielding parameters from Phy-X/PSD program showed higher values of mass (MAC) and linear attenuation coefficients (LAC), and effective atomic number (Zeff) in the order of; glass Ce+Gd > glass Ce > glass Gd. Ce + Gd doped glass revealed also the lowest half value layer (HVL) comparing to other shielding commercial concretes. The study recommends the beneficial and economical use of the useless MSW ash to produce CeO2 and/or Gd2O3 borosilicate glasses with hopeful radiation shielding features.

Analyzing the long-term effects of e-glass mortar on sustainability and radiation shielding using ANOVA.

Significant investigations were performed on the use and impact on physical properties along with mechanical strength of the recycled and reused e-glass waste powder. However, it has been modeled how recycled display e-waste glass may affect the characteristics and qualities of dune sand mortar. This study investigates the long-term feasibility of using recycled display e-glass waste as a partial substitute for dune sand at varying percentages (5%, 10%, 15%, and 20%). The main focus is on evaluating its effectiveness in radiation shielding, strength properties, and durability for long-term development under the heating environmental process. Statistical analyses, including analysis of variance, are used to assess the significance of factors and their interactions on these characteristics. Additionally, a regression equation derived from the model offers insights into the quantitative relationship between the factors and properties. The results of the experiments led to the conclusion that the most effective proportion of e-glass waste to include in mortar is 20%, with the weight of dune sand. Including e-glass waste, they significantly increased the five characteristics of the mortar, making it suitable for high-strength mortar applications continue up to 68 MPa. The ANOVA model used in this study was trained using the same experimental research design and was critical in predicting the properties of the mortar. The model produced an accurate result with an R2 value greater than 0.99. E-glass replacements exhibit remarkable radiation shielding, characterized by pozzolanic activity and superior internal bonding due to its compact texture, contributing to enhanced long-term strength.

Design and Construction of a Radiochemistry Laboratory and cGMP-Compliant Radiopharmacy Facility.

The establishment of a compliant radiopharmacy facility within a university setting is crucial for supporting fundamental and preclinical studies, as well as for the production of high-quality radiopharmaceuticals for clinical testing in human protocols as part of Investigational New Drug (IND) applications that are reviewed and approved by the U.S. Food and Drug Administration (FDA). This manuscript details the design and construction of a 550 ft2 facility, which included a radiopharmacy and a radiochemistry laboratory, to support radiopharmaceutical development research and facilitate translational research projects. The facility was designed to meet FDA guidelines for the production of aseptic radiopharmaceuticals in accordance with current good manufacturing practice (cGMP). A modular hard-panel cleanroom was constructed to meet manufacturing classifications set by the International Organization of Standardization (ISO), complete with a gowning room and an anteroom. Two lead-shielded hot cells and two dual-mini hot cells, connected via underground trenches containing shielded conduits, were installed to optimize radioactive material transfer while minimizing personnel radiation exposure. Concrete blocks and lead bricks provided sufficient and cost-effective radiation shielding for the trenches. Air quality was controlled using pre-filters and high-efficiency particulate air (HEPA) filters to meet cleanroom ISO7 (Class 10,000) standards. A laminar-flow biosafety cabinet was installed in the cleanroom for preparation of sterile dose vials. Noteworthy was a laminar-flow insert in the hot cell that provided a shielded laminar-flow sterile environment meeting ISO5 (class 100) standards. The design included the constant control and monitoring of differential air pressures across the cleanroom, anteroom, gowning room, and controlled research space, as well as maintenance of temperature and humidity. The facility was equipped with state-of-the-art equipment for quality control and release testing of radiopharmaceuticals. Administrative controls and standard operating procedures (SOPs) were established to ensure compliance with manufacturing standards and regulatory requirements. Overall, the design and construction of this radiopharmacy facility exemplified a commitment to advancing fundamental, translational, and clinical applications of radiopharmaceutical research within an academic environment.

Experimental investigation of radiation shielding competence of B2O3-Na2O-Al2O3-BaO-CaO glass system.

Aiming to extend the scope of utilizing glass in radiation shielding, this work investigates the radiation interaction response of a borate-based glass system. Four borate-glass samples of different substituting concentrations of calcium oxide ( 70 - x )B2O3: 10 Na2O : 5 Al2O3 : 15 BaO: x CaO were prepared. To assess the shielding performance of the prepared glass samples, a high-purity germanium detector and different radioactive sources (different energies) were used. Via the narrow beam method, the linear attenuation coefficients (LACs) were experimentally measured. So, the transmission factor (TF), the half-value layer (HVL), the tenth value layer (TVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were calculated for all prepared samples. It was observed that the increase of the concentration of calcium oxide in the proposed borate-based glass samples leads to improve their performance in shielding against radiation. At low energy, the RPE of the samples is almost 100%. However, it was observed that as energy of the radiation source increases, the shielding performance of the samples will decrease. High energy dependence was found when calculating TF, HVL, TVL, and MFP. They were increased with the increase of the energy of the incident photons. At 0.662 MeV, the TF values are equal to 79.26, 79.00, 79.72, and 78.43% for BNABC-1, BNABC-2, BNABC-3, and BNABC-4 in the same oder, respectively. The application of the proposed composition of borate-based glass as a transparent shield against low-energy ionizing radiation was highlighted.

Radiation safety of ultra-high dose rate electron accelerators for FLASH radiotherapy.

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.

3D Printing of Composite Radiation Shielding for Broad Spectrum Protection of Electronic Systems.

The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built-in redundancies, and radiation-hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly. Here, a versatile material platform and process to conformally print customized composite inks at room temperature directly and selectively onto commercial-off-the-shelf electronics is described. The suite of inks uses a flexible styrene-isoprene-styrene block copolymer binder that can be filled with particles of different atomic densities for diverging radiation shielding capabilities. Additionally, the system enables the combination of multiple distinct particle species within the same printed structure. The method can produce graded shielding that offers improved radiation attenuation by tailoring both shield geometry and composition to provide comprehensive protection from a broad range of radiation species. The authors anticipate this alternative to traditional shielding methods will enable the rapid proliferation of the next generation of compact satellite designs.

Structural, radiation shielding, thermal and dynamic mechanical analysis for waste rubber/EPDM rubber composite loaded with Fe2O3 for green environment.

Increasing waste rubber recycling produces a specious range of products for many valuable applications. Waste Rubber/EPDM composite with different concentrations was prepared. Infrared spectroscopy (FTIR) is used to identify the chemical composition. A water absorption test, Dynamic mechanical analysis (DMA), and Thermal Gravimetric Analysis (TGA) were performed. The (75/25) WR/EPDM rubber composite exhibited the best behavior with the highest mechanical performance. Fe2O3 was added to (75/25) WR/EPDM rubber composite. Water absorption, FTIR, TGA, and DMA were investigated. The composite performance was improved with increasing Fe2O3 content. The linear attenuation coefficients (µ) were also measured as a function of the concentrations of Fe2O3 for γ-ray energy 662 keV by using 137Cs point source; the radiation shielding can be denoted by numbers of parameters like mass attenuation coefficient (µm), half value layer (HVL), Tenth value layer TVL and radiation protection efficiency (RPE%), radiation protection efficiency increased as Fe2O3 increased.

Secondary proton buildup in space radiation shielding.

The risk posed by prolonged exposure to space radiation represents a significant obstacle to long-duration human space exploration. Of the ion species present in the galactic cosmic ray spectrum, relativistic protons are the most abundant and as such are a relevant point of interest with regard to the radiation protection of space crews involved in future long-term missions to the Moon, Mars, and beyond. This work compared the shielding effectiveness of a number of standard and composite materials relevant to the design and development of future spacecraft or planetary surface habitats. Absorbed dose was measured using Al2O3:C optically stimulated luminescence dosimeters behind shielding targets of varying composition and depth using the 1 GeV nominal energy proton beam available at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory in New York. Absorbed dose scored from computer simulations performed using the multi-purpose Monte Carlo radiation transport code FLUKA agrees well with measurements obtained via the shielding experiments. All shielding materials tested and modeled in this study were unable to reduce absorbed dose below that measured by the (unshielded) front detector, even after depths as large as 30 g/cm2. These results could be noteworthy given the broad range of proton energies present in the galactic cosmic ray spectrum, and the potential health and safety hazard such space radiation could represent to future human space exploration.

Novel Polymer Composites for Lead-Free Shielding Applications.

Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding materials were developed using low-density polyethylene (LDPE) mixed with four different filler materials. These four materials are cement, cement with iron oxide, cement with aluminum oxide, and cement with bismuth oxide. Different weight percentages were used including 5%, 15%, and 50% of the cement filler with LDPE. Furthermore, different weight percentages of different combinations of the filler materials were used including 2.5%, 7.5%, and 25% (i.e., cement and iron oxide, cement and aluminum oxide, cement and bismuth oxide) with LDPE. Bismuth oxide was a nanocomposite, and the remaining oxides were micro-composites. Characterization included structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared composites. The results show that a clear improvement in the shielding efficiency was observed when the filler materials were added to the LDPE. The best result out of all these composites was obtained for the composites of bismuth oxide (25 wt.%) cement (25 wt.%) and LDPE (50 wt.%) which have the lowest measured mean free path (MFP) compared with pure LDPE. The comparison shows that the average MFP obtained from the experiments for all the eight energies used in this work was six times lower than the one for pure LDPE, reaching up to twelve times lower for 60 keV energy. The best result among all developed composites was observed for the ones with bismuth oxide at the highest weight percent 25%, which can block up to 78% of an X-ray.

Scattered high-energy synchrotron radiation at the KARA visible-light diagnostic beamline.

To characterize an electron beam, visible synchrotron light is often used and dedicated beamlines at synchrotron sources are becoming a more common feature as instruments and methods for the diagnostics are, along with the accelerators, further developed. At KARA (Karlsruhe Research Accelerator), such a beamline exists and is based on a typical infrared/visible-light configuration. From experience at such beamlines no significant radiation was expected (dose rates larger than 0.5 µSv h-1). This was found not to be the case and a higher dose was measured which fortunately could be shielded to an acceptable level with 0.3 mm of aluminium foil or 2.0 mm of Pyrex glass. The presence of this radiation led to further investigation by both experiment and calculation. A custom setup using a silicon drift detector for energy-dispersive spectroscopy (Ketek GmbH) and attenuation experiments showed the radiation to be predominantly copper K-shell fluorescence and is confirmed by calculation. The measurement of secondary radiation from scattering of synchrotron and other radiation, and its calculation, is important for radiation protection, and, although a lot of experience exists and methods for radiation protection are well established, changes in machine, beamlines and experiments mean a constant appraisal is needed.

An extensive assessment of the impacts of BaO on the mechanical and gamma-ray attenuation properties of lead borosilicate glass.

The current work deals with the synthesis of a new glass series with a chemical formula of 5Al2O3-25PbO-10SiO2-(60-x) B2O3-xBaO; x was represented as 5, 10, 15, and 20 mol%. The FT-IR spectroscopy was used to present the structural modification by rising the BaO concentration within the synthesized glasses. Furthermore, the impacts of BaO substitution for B2O3 on the fabricated borosilicate glasses were investigated using the Makishima-Mackenzie model. Besides, the role of BaO in enhancing the gamma-ray shielding properties of the fabricated boro-silicate glasses was examined utilizing the Monte Carlo simulation. The mechanical properties evaluation depicts a reduction in the mechanical moduli (Young, bulk, shear, and longitudinal) by the rising of the Ba/B ratio in the fabricated glasses. Simultaneously, the micro-hardness boro-silicate glasses was reduced from 4.49 to 4.12 GPa by increasing the Ba2+/B3+ ratio from 0.58 to 3.18, respectively. In contrast, the increase in the Ba/B ratio increases the linear attenuation coefficient, where it is enhanced between 0.409 and 0.448 cm-1 by rising the Ba2+/B3+ ratio from 0.58 to 3.18, respectively. The enhancement in linear attenuation coefficient decreases the half-value thickness from 1.69 to 1.55 cm and the equivalent thickness of lead is also reduced from 3.04 to 2.78 cm, at a gamma-ray energy of 0.662 MeV. The study shows that the increase in the Ba2+/B3+ ratio enhances the radiation shielding capacity of the fabricated glasses however, it slightly degrades the mechanical properties of the fabricated glasses. Therefore, glasses with high ratios of Ba2+/B3+ have high gamma-ray shielding ability to be used in hospitals as a shielding material.

Physical, structural and nuclear radiation shielding behavior of Ni-Cu-Zn Fe2O4 ferrite nanoparticles.

In this study, Ni-Cu-Zn Fe2O4 ferrite nanoparticles have successfully been synthesized utilizing the Co-precipitation technique. The primary objectives encompassed elucidating phase purity, discerning functional groups, scrutinizing surface morphology, and conducting structural analyses. To accomplish these objectives, a battery of advanced characterization techniques was employed, including power X-ray diffraction, Transmission infrared spectroscopy, UV-Visible spectrophotometer, and Scanning electron microscopy. Furthermore, the investigation was extended to the assessment of the gamma ray shielding properties exhibited by the synthesized Ni-Cu-Zn Fe2O4 nanoparticles, spanning an energy range from 122 keV to 1330 keV. This evaluation was carried out through the utilization of a NaI(Tl) detector coupled with a PC-based multichannel analyzer. The acquired data were meticulously compared with established theoretical value. The results of this study point to a viable route for using this simple, cost-effective, and low-temperature synthesis approach to create nanomaterials suited for gamma ray shielding applications, as well as broader radiation protection. This novel technique has the potential to significantly improve radiation shielding technology. Along with this fast neutron attenuation capability of this prepared ferrite samples have been studied in terms of fast neutron removal cross section.

Radiation shielding assessment for interventional radiology personnel: Geant4 dosimetry of lead-free compositions.

The inherent biological hazards associated with ionizing radiation necessitate the implementation of effective shielding measures, particularly in medical applications. Interventional radiology, in particular, poses a unique challenge as it often exposes medical personnel to prolonged periods of high x-ray doses. Historically, lead and lead-based compounds have been the primary materials employed for shielding against photons. However, the drawbacks of lead, including its substantial weight causing personnel's inflexibility and its toxicity, have raised concerns regarding its long-term impact on both human health and the environment. Barium tantalate has emerged as a promising alternative, due to its unique attenuation properties against low-energy x-rays, specifically targeting the weak absorption area of lead. In the present study, we employ the Geant4 Monte Carlo simulation tool to investigate various formulations of barium tantalate doped with rare earth elements. The aim is to identify the optimal composition for shielding x-rays in the context of interventional radiology. To achieve this, we employ a reference x-ray spectrum typical of interventional radiology procedures, with energies extending up to 90 keV, within a carefully designed simulation setup. Our primary performance indicator is the reduction in air kerma transmission. Furthermore, we assess the absorbed doses to critical organs at risk within a standard human body phantom protected by the shield. Our results demonstrate that specific concentrations of the examined rare earth impurities can enhance the shielding performance of barium tantalate. To mitigate x-ray exposure in interventional radiology, our analysis reveals that the most effective shielding performance is achieved when using barium tantalate compositions containing 15% Erbium or 10% Samarium by weight. These findings suggest the possibility of developing lead-free shielding solutions or apron for interventional radiology personnel, offering a remarkable reduction in weight (exceeding 30%) while maintaining shielding performance at levels comparable to traditional lead-based materials.

Recent Advances and Challenges in Polymer-Based Materials for Space Radiation Shielding.

Space exploration requires the use of suitable materials to protect astronauts and structures from the hazardous effects of radiation, in particular, ionizing radiation, which is ubiquitous in the hostile space environment. In this scenario, polymer-based materials and composites play a crucial role in achieving effective radiation shielding while providing low-weight and tailored mechanical properties to spacecraft components. This work provides an overview of the latest developments and challenges in polymer-based materials designed for radiation-shielding applications in space. Recent advances in terms of both experimental and numerical studies are discussed. Different approaches to enhancing the radiation-shielding performance are reported, such as integrating various types of nanofillers within polymer matrices and optimizing the materials design. Furthermore, this review explores the challenges in developing multifunctional materials that are able to provide radiation protection. By summarizing the state-of-the-art research and identifying emerging trends, this review aims to contribute to the ongoing efforts to identify polymer materials and composites that are most useful to protect human health and spacecraft performance in the harsh radiation conditions that are typically found during missions in space.

Valorisation of baryte tailings for radiation shielding in plastics and nuclear waste disposal.

Baryte (BaSO4) is a critical raw material with no functional recycling since the used applications are dissipative. Significant quantities of baryte end up in tailings as a side stream from the mining industry. Baryte from a secondary raw material source was used as a filler in plastics for low duty radiation shielding and as an aggregate in radiation shielding geopolymers needed for safely storing low-radioactive waste ash. Mechanical strength in geopolymers remained at a high level with 0-50 % baryte additions. Low-cost plastic composites with baryte additions showed promising attenuation for X-rays and gamma-rays. The results showed improved qualities in the direct use of the secondary baryte material in concrete and plastics in comparison to primary baryte. Baryte from an industrial waste stream was shown to be applicable to be used in radiation shielding in geopolymers for storing low-radioactive waste, and in plastics. Primary baryte can be replaced with secondary baryte to bring environmental, economic, and even functional benefits.