Radiation Shielding Effectiveness Research Articles

Thin-film assembly via encapsulation of nano-aluminum oxide-linked-pb(II)-2,4-dinitroaniline complex into a polymeric matrix as efficient radiation shielding materials

Radiation safety and protection is a subject of major concern for all communities because of the biological damage caused by different radiation sources. Therefore, the purpose of this study is aimed to synthesize two different thin films from a newly synthesized N-Al2O3@Pb(II)-2,4-DiNA nanocomposite which was prepared by the direct chemical coupling of nano-aluminum oxide (N-Al2O3) with Pb(II)-2,4-dinitroaniline complex. The synthesized materials were characterized by FT-IR, thermogravimetric analysis (TGA), scanning electron microscope SEM, and elemental composition by energy-dispersive X-ray (EDX). The two thin films were assembled by the encapsulation of N-Al2O3@Pb(II)-2,4-DiNAnanocompositeinto hydrolyzed polyurethane and hydrolyzed polyvinyl chloride. Electron spin resonance (ESR) measurements have been used to investigate the newly prepared nanocomposite and thin films before and after gamma irradiation. Gamma spectroscopy, Phy-X software, and SRIM (stopping and range of ions in matter) Monte Carlo simulation code are aimed to apply and investigate radiation shielding efficiency of films for gamma/x-ray, protons, alpha, and thermal neutrons. The gamma shielding characteristics, mass stopping power (MSP), and range for both proton (H-ions) and alpha (He-ions) were also calculated. In addition, the SRIM code’s subroutine TRIM was used to predict the damage production and atomic displacements per atom (dpa) caused by the interaction of high-energy H-ions (proton) and He-ions (alpha) with the studied samples. The data obtained the good radiation shielding effect of the prepared thin films and their possible use as radiation shielding materials for X-rays and low gamma energy.

CoCrFeNiSi high entropy alloy: Synthesis, structural and radiation shielding properties

High entropy alloys (HEAs) have emerged as a distinct class of alloys with unique design strategies, different from traditional alloys. These alloys hold great promise for diverse applications, and the investigation of their nuclear radiation shielding properties has become an important and emerging area of research. In this experimental study, an equimolar CoCrFeNiSi HEA was prepared using the ball milling method. The focus was on characterizing the crystalline structure, morphological features, and radiation shielding properties of the synthesized HEA. X-ray diffraction analysis revealed that the HEA exhibited a face-centered cubic (FCC) phase structure. The crystallite size was significantly reduced from 23.63 nm to 3.22 nm, indicating the refinement of the microstructure. The homogeneity of the alloy was confirmed through scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), which showed that the five elements were uniformly distributed within the powder alloy. To evaluate the radiation shielding properties, linear attenuation coefficients (LAC) of the CoCrFeNiSi HEA powder were measured using a 662 keV gamma source and a NaI(Tl) detector system (ORTEC® 905–4). The experimental LAC values were determined to be 0.2140 ± 0.01 cm⁻1. Theoretical calculations using MCNP6.2 and XCOM code were also performed and showed good agreement with the experimental results. Comparing the CoCrFeNiSi HEA with common shield materials such as thin films, glass systems, and some composites, it was found that the HEA outperformed them in terms of radiation shielding effectiveness. This demonstrates the potential of the CoCrFeNiSi HEA as an advanced alternative to conventional shielding materials, with potential applications in various fields.

The use of low‐density polyethylene‐molybdenum oxide polymer composites as radiation shielding laminates in dental radiology physical structures

AbstractRadiation protection is crucial in the protection of humans from the harmful effects of ionizing radiation. One of the most reliable ways of reducing the risk of occupationally exposed workers and the public in dental radiology is the installation of an effective radiation shielding barrier at the facility. Concrete barriers are predominantly used for dental shielding, however there is need to consider the use of lighter, ready‐made, and lower half value layer (HVL) materials as shielding materials in dental radiology facilities. In this work, low‐density polyethylene‐molybdenum oxide polymer composites were prepared (85C2H4‐15MoO3, 90C2H4‐10MoO3, and 95C2H4‐5MoO3), and the radiation attenuation measurements were carried out experimentally. The composites displayed acceptable x‐ray absorbing capabilities. 85C2H4‐15MoO3 polymer composite (DT1) showed optimal shielding in comparison with concrete. DT1 has an approximate HVL like concrete while it is 54.3% lighter than concrete. 85C2H4‐15MoO3 polymer composite is 1.5%, 0.8%, and 6.3% higher in linear attenuation coefficient than concrete at 60, 70, and 80 kVps, respectively. This implies that DT1 can effectively replace concrete at dental diagnostic energies.

The Properties of Bi2O3 Additive on Radiation Shielding and Elastic Moduli Properties of TeO2–P2O5 Based Glass System

The radiation shielding and elastic moduli properties of (60–x)TeO2–30P2O5–xBi2O3 (x increased from 10–50 mol% in 10 mol% increments) glass series have been discussed. The radiation shielding quantities such as mass attenuation coefficient (µ m), effective atomic numbers (Z eff), half value layer (HVL) and mean free path (MFP) were calculated using Phy–X/PSD program at energies ranging from 1 keV–100 GeV while exposure and energy absorption buildup factors (EBF and EABF) were evaluated using geometric progression (G–P) fitting method at energies ranging 0.015–15 MeV for penetration depths (PD) until 40 mean free path (mfp). In addition, the density and elastic moduli were estimated. The results found that the TPB5 glass sample having the largest content of Bi2O3 possessed the highest density and excellent radiation shielding properties. This reflected that replacing TeO2 with Bi2O3 improved effective radiation shielding. In addition, the MFP for glass series were lower than the hematite-serpentine concrete. It indicated that this glass series are photon shielding better than the hematite-serpentine concrete. Whereas, this sample had the lowest elastic moduli. These results indicated that Bi2O3, a network modifier, has broken glass network bonds and formed non–bridging oxygen (NBOs) which affects the elastic moduli of the glass system.

High transparency of PbO–BaO–Fe2O3–SrO–B2O3 glasses with improved radiation shielding properties

This study investigated the role of PbO and BaO on the optical and radiation shielding properties of PbO–Fe2O3–SrO–B2O3–BaO glass systems. Optical studies indicate that the prepared glass samples are transparent within the visible spectrum; the transparency increases marginally with increasing PbO/BaO concentrations. Furthermore, by increasing the PbO/BaO ratio, the BO4 units increase (BO3 units decrease), and the density values increase. In addition, the optical band gaps widen, and linear and nonlinear refractive indices decrease. The reductions in nonbridging oxygen were responsible for the increased band gaps and decreased refractive index behavior. Moreover, the ionizing radiation shielding studies showed improved behavior with additional PbO additives. Also, the HVL values of the present glass samples are comparatively lower than the HVL of some standard ionizing radiation shielding materials. Finally, the combination of effective radiation shielding properties and high transparency makes the current glass samples good candidates in the ionizing radiation shielding field.

Chemical and radiation shielding effectiveness of some heavy metal oxide glasses for immobilizing radioactive wastes

Ce/Sb/Mn different borate glass systems based PbO in concentrations of 50, 35, and 15 mol%, respectively, were prepared by the melting–annealing method. Wide chemical, structural, and radiation shielding characterizations were studied before and after 120 kGy of gamma radiation to test the possible use of glasses for immobilizing radioactive wastes. The results showed suitable density values ranging from 3.34 to 5.30 g/cm3 increased by irradiation. FTIR spectra revealed high structural stability against irradiation correlated to the trigonal BO3, tetrahedral BO4 groups, high polarizable Pb2+ ions, and the doped metal ions. Unexpectedly, the chemical durability after in situ leaching process in H2O, 0.1 N HCl, and 0.1 N NaOH for ~ 3 months revealed clear improving after irradiation e.g., enhanced by ~ 25% for Ce-lead borate glass. Scanning electron microscope (SEM) images of the glass surfaces revealed more smooth and homogenous surfaces after irradiation. Shielding parameters by Monte Carlo code (MCNP5) and Phy-X/PSD software were studied, e.g., mass and linear attenuation coefficients (MAC and LAC), effective atomic number (Zeff), radiation protection efficiency (RPE%), half and tenth value layers (HVL and TVL), and heaviness%. Comparing the shielding behavior of the three glasses revealed that Ce-lead borate glass has the highest values of LAC, MAC, Zeff, heaviness%, and RPE% and the lowest values of HVL, TVL, and MFP, referring to the best shielding efficiency. The whole study indicates the desired properties of glasses as immobilizers or containers for radioactive wastes, e.g., nuclear medicine units in hospitals, especially lead borate glass doped Ce ions.Graphical

Impacts of BaO additions on structure, linear/nonlinear optical properties and radiation shielding competence of BaO–NiO–ZnO–B2O3 glasses

The purpose of this research is to study the structure, optical and radiation shielding effectiveness of radiation shielding glasses based on the formula [x BaO–(80-X) B2O3– 1NiO–11ZnO]; x = 8, 16, 24 and 32 mol%] have been obtained from melt quenching method. The density was increased from 2.861 (± 0.001) g.cm−3 to 3.119 (± 0.001) g.cm−3 due to an effective concentration of BaO. Furthermore, the vibrational investigations confirmed the conversion from trigonally-coordinated boron units (B O3) to tetrahedrally-coordinated boron units (B O4) with progressive enhancement in tetrahedrally-coordinated boron ratio (N4), besides a significant deterioration in non-bridging oxygen units (NBOs) inside the glass network due to the further concentrations of BaO. Optical studies showed the increase in optical band gaps from 3.22 (± 0.01) eV to 3.40 (± 0.01) eV with further concentrations of BaO from 8 to 32 mol%. This increment was attributed to the reduced NBO concentrations inside the glass network. Moreover, the nonlinear optical parameters showed decreased values due to the effective addition of BaO. Furthermore, the radiation shielding studies showed that the addition of BaO to the present glasses is an effective way to improve their radiation shielding performance. Additionally, to better understand the radiation protection provided by these glasses, a comparison of their half-value layers (HVL) with those of previously reported glasses was carried out at 0.662 MeV of photon energies. This comparison confirmed the improved radiation shielding performance of the present glass system.

Graphene Nanocomposites for Electromagnetic Interference Shielding—Trends and Advancements

Electromagnetic interference is considered a serious threat to electrical devices, the environment, and human beings. In this regard, various shielding materials have been developed and investigated. Graphene is a two-dimensional, one-atom-thick nanocarbon nanomaterial. It possesses several remarkable structural and physical features, including transparency, electron conductivity, heat stability, mechanical properties, etc. Consequently, it has been used as an effective reinforcement to enhance electrical conductivity, dielectric properties, permittivity, and electromagnetic interference shielding characteristics. This is an overview of the utilization and efficacy of state-of-the-art graphene-derived nanocomposites for radiation shielding. The polymeric matrices discussed here include conducting polymers, thermoplastic polymers, as well as thermosets, for which the physical and electromagnetic interference shielding characteristics depend upon polymer/graphene interactions and interface formation. Improved graphene dispersion has been observed due to electrostatic, van der Waals, π-π stacking, or covalent interactions in the matrix nanofiller. Accordingly, low percolation thresholds and excellent electrical conductivity have been achieved with nanocomposites, offering enhanced shielding performance. Graphene has been filled in matrices like polyaniline, polythiophene, poly(methyl methacrylate), polyethylene, epoxy, and other polymers for the formation of radiation shielding nanocomposites. This process has been shown to improve the electromagnetic radiation shielding effectiveness. The future of graphene-based nanocomposites in this field relies on the design and facile processing of novel nanocomposites, as well as overcoming the remaining challenges in this field.

Boron containing polyvinyl alcohol/ polyethylene oxide/polyvinyl pyrrolidone composites: Preparation, characterization, gamma radiation shielding and gamma radiation effect on it's thermal properties

The production of PVA/PEO/PVP-B4C and PVA/PEO/PVP-BN nanocomposites is presented in this study by adding certain proportions of boron nitride (BN) and boron carbide (B4C) to the polyvinyl alcohol(PVA)/polyethylene Oxide (PEO)/polyvinyl pyrrolidone (PVP) blend. The percentages of BN and B4C nano powder in the PVA/PEO/PVP blend have been determined as 5%, 10% and 20%. Thermal characterizations were carried out with different techniques such as Differential scanning calorimetry (DSC), Differential Thermal Analysis (DTA), Thermogravimetry (TG). Surface, crystal structure and atomic percentage distribution analyzes of the obtained composites were performed by X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), and elemental analysis. 10 kGy gamma irradiation was performed on PVA/PEO/PVP-B4C and PVA/PEO/PVP-BN composites. The thermal behavior of the composites at this dose level was investigated. In addition, the radiation shielding properties of composite films obtained at 10 cm distances using Am-241 beam source were examined.

Copper-nickel electroplating of 3D-printed acrylonitrile butadiene styrene for interference and radiation shielding applications

In this study, electromagnetic and radiation shielding structures were fabricated by 3D printing acrylonitrile butadiene styrene (ABS) structures via fused filament fabrication and electroplating with copper (Cu) and nickel (Ni) metals. Prior to electroplating, the printed ABS materials were made conductive by surface electrodepositon of polypyrrole (PPy). ABS adsorbs the pyrrole monomer, which subsequently polymerizes via oxidation forming conductive PPy layer on the printed structures. The successful anchoring of PPy layer can be attributed to its hydrogen bonding and electrostatic interactions with ABS. Thermal analysis, optical, and electron microscopy equipped with energy dispersive X-ray were employed to characterize the printed shielding structures, while the interference and radiation shielding effectiveness were evaluated using a spectrum analyzer and dosimeter, respectively. The interference shielding was found to be effective at 60 ± 5 dB over relatively small frequency range. Shielding was also apparent against gamma and X-ray ionizing rays, but more significantly effective against beta rays. Furthermore, the Cu/Ni coating was able to reduce any heat-induced dimensional changes for the 3D printed ABS substrate without compromising the mechanical integrity.

Radiation attenuation effectiveness of polymer-based radiation shielding materials for gamma radiation

Polymer materials are increasingly being utilised in radiation shielding applications due to their unique characteristics such as flexibility, durability, and cost-effectiveness. These properties have attracted the attention of researchers who have been exploring the potential of these materials in such applications. Recently, new radiation shielding materials have been developed by incorporating elements into polymer matrices. The purpose of this study was to assess the effectiveness of lead-free polymer-based radiation shielding bricks in attenuating gamma radiation at 140 keV and 364 keV. The study evaluated the radiation shielding capability of five different polymer-based bricks, which were prepared using an open-mould casting technique with thicknesses of 0.7 cm and 1.4 cm. The bricks were fabricated by loading 90% filler powder and 10% epoxy resin and hardener. The filler powders used in this study were tungsten carbide, tungsten carbide cobalt, bismuth oxide, barium sulphate, and tin powder. The effectiveness of the fabricated bricks in attenuating gamma radiation was evaluated at 140 keV and 364 keV, and their microstructural properties were analysed using field emission scanning electron microscopy (FESEM). The study found that the newly developed polymer-based radiation shielding bricks can attenuate gamma radiation up to 98% at 140 keV and 65% at 364 keV of the incident gamma radiation. The FESEM analysis showed that the fillers were evenly distributed within the epoxy matrix. In conclusion, the incorporation of tungsten carbide, tungsten carbide cobalt, bismuth oxide, barium sulphate, and tin particles into the epoxy matrix improves the radiation shielding effectiveness of polymer-based materials, making them suitable for gamma radiation shielding applications.

Composite cellulose/Fe3O4/Cu for effective X-ray radiation shielding

In this study, a cellulose/Fe3O4/Cu composite was synthesized by the blending method and applied as an X-ray radiation apron. The content of Fe3O4 in each sample was 94 wt%, and the varying levels of cellulose and Cu were 1, 2, 3, 4, and 5 wt%. The crystal phase formed in the sample was observed using X-ray diffraction, and the functional group formed was examined using Fourier transform infrared spectroscopy. The performance of the sample as a radiation shield was analyzed using X-ray mobile with energies of 50, 60, 70, 81, and 90 keV at 10 mAs applied to the sample. The results showed that the samples with composition of 2 wt% cellulose and 4 wt% Cu exhibited the best values for the average size of the smallest crystallite size (12.21 nm), low transmittance, linear attenuation coefficient (μ), mass attenuation coefficient (μm), atomic cross-section (σa), electronic cross-section (σel), half value layer, and mean free path. Alterations observed on the surface of the composite material suggested the impact of incorporating metallic components into nonmetallic constituents. Surface analysis was conducted using scanning electron microscope and revealed that the surface model resembled Brassica oleracea. This feature is advantageous due to the large surface area and absorbent properties associated with such leaves.

Effect of gamma ray irradiation on optical and luminescence properties of CeO2 doped bismuth glass

High lead oxide based Radiation Shielding Window (RSW) glass is highly toxic in nature and thus health hazardous. Therefore, a new way to design environmental friendly non-toxic lead-free RSW glass for nuclear application is very much required. In this work, a lead-free non-toxic glass based on multi-component Bi2O3–BaO–B2O3–ZnO–As2O3–MgO–Na2O system has been studied with different concentrations of cerium oxide (CeO2) as doping agent for enhancing radiation shielding effect. The optical properties of cerium doped bismuth based lead-free radiation shielding glass after exposure to gamma radiation up to 105 rad have been studied. The densities of glass varied from 4.59 to 5.05 g/cc on varying concentrations of bismuth oxide and boron trioxide in glass system. The transmission properties in visible regions from 400 to 1000 nm are investigated through UV–visible spectrometer after exposure to gamma radiation on developed glass using 60Co Gamma Chamber GC5000. The structure of glass as characterized by Raman spectroscopy, XRD, Photoluminescence (PL), FESEM with EDAX, refractive index measurement and dilatometry test has been correlated with its properties. The developed bismuth glass could find its application as lead-free RSW glass in nuclear reactors as an alternative to high lead containing glass.

How does 2D and 3D of urban morphology affect the seasonal land surface temperature in Island City? A block-scale perspective

The global climate warming caused by urbanization has significantly affected the urban environment. Whilst land surface temperature (LST) is an important factor reflecting urban temperature, previous research on LST mostly focused on two-dimensional (2D) factors and rarely mentioned about the role of three-dimensional (3D) factors, particularly the LST variation characteristics of island cities. Therefore, this study examined the seasonal variation characteristics of urban LST by analyzing the impact of 2D and 3D urban morphology factors of different urban block types on LST in Xiamen Island. The main results are as follows. First, compact low layer (CL), a block type with a higher density of low-rise buildings, has a higher LST in any season. Under the same block density (BD), the higher the block average height (BH), the lower the LST. Second, among the 2D urban morphology factors, normalized difference vegetation index (NDVI) was the main factor for cities to reduce urban LST, especially in summer, while normalized difference built-up index (NDBI) was the opposite. Different from land cities, we found a positive correlation between modified normalized difference water body index (MNDWI) and LST in autumn and winter. Third, in the 3D urban morphology factors, sky view factor (SVF) was significantly positively correlated with LST, while building fluctuation (BF) was negatively correlated. The higher the SVF, the worse the radiation shielding effect between buildings. On the contrary, the higher the BF, the higher the building undulation, and the better the building radiation shielding. These findings should provide some quantitative insights for the future construction and planning of island cities, which can be used to improve the thermal environment of island cities and support the sustainable development of cities.

The Zenith‐Angle Dependence of the Downward Radiation Dose Rate on the Martian Surface: Modeling Versus MSL/RAD Measurement

AbstractThe Radiation Assessment Detector (RAD) on board the Mars Science Laboratory's Curiosity rover has been monitoring the surface radiation environment on Mars for just over 10 years. It has been found by Wimmer‐Schweingruber et al. (2015, https://doi.org/10.1002/2015gl066664) that within the narrow view cone of RAD, the directionality of the radiation field is close to but not completely isotropic. In order to better understand the directionality of the surface radiation over a wide range of zenith angles (θ), we perform a three‐dimensional Geant4 Monte Carlo simulation to derive the θ‐dependence of the surface dose rate. The results show that galactic cosmic ray protons, coming in at θ ∼ 74° make the greatest contribution to the surface dose. For helium ions, this angle is at around 46°. This is a consequence of the increasing column depth at larger zenith angles and the complex interplay of the destruction of primary and the creation of secondary particles as the primary cosmic ray interacts with the Martian atmosphere. We also compared the simulated results with the RAD measurements and found a reasonable agreement. Our results are important for future human exploration of Mars, for instance, to estimate the effectiveness of radiation shielding of a given geometry or for optimizing the radiation shielding design of a Martian habitat.

Analysis of radiation shielding effectiveness of hydride and borohydride metals for nuclear industry

Hydrogenous materials are of great interest in nuclear industry because of the ability of hydrogen to slow-down neutrons. In comparison with common hydrogenous materials, metal hydrides highly enriched with hydrogen at high temperatures and good mechanical properties. This study concerns on evaluation the requirements for photons, charged particles and fast neutrons shielding parameters for several types of hydride and borohydride metals. Firstly, photons shielding ability of these materials were examined using Phy-X/PSD program. Assigning the attenuation factors of photons were evaluated for an energy range (1 keV–100 GeV). Secondly, the charged particle (electron, proton and alpha particle) interactions were examined by using ESTAR (Stopping Powers and Ranges for Electrons) and SRIM (The Stopping and Range of Ions in Matter) programs. Finally, fast neutron attenuation was tested by calculating the removal cross-sections (ΣR) for neutron with energy 4.5 MeV. The dependence of photons, charged particles and fast neutrons parameters on the constituent of tested samples was given and discussed. The obtained results through this work show that, the shielding proficiency parameters depend on the energy of the incident radiation and chemical constituents of the examined materials. As well as, these results showed that BaH2, ZrH2, VH2 and TiH2 samples own a good shielding performance compared to the other investigated samples.

Development of a novel high-energy electron shielding Ta/Al composite coating for electronic packaging material via cold spray

To protect electronic components of satellite/spacecraft from high-energy electron radiations in the geostationary earth orbit (GEO) environment, a novel radiation shielding Ta/Al composite coating was successfully deposited on electronic packaging material (Al2O3) by cold spray. Results showed that the radiation shielding effectiveness (against 1 MeV electron irradiation with the delivered dose of ∼60 kGy) of the prepared coating with a thickness of 0.3 mm can reach as high as 98.5% due to the synergistic effect of Ta (high atomic number, high-Z) and Al (low atomic number, low-Z) materials. Moreover, the microstructure of the prepared coating remained intact after 1 MeV electron irradiation. Overall, cold sprayed Ta/Al composite coating exhibited excellent shielding ability against high-energy electron radiation.

Physical, structural, elastic and optical investigations on Dy3+ ions doped boro-tellurite glasses for radiation attenuation application

A set of Dy3+ ions doped boro-tellurite glasses is prepared using the melt quenching method and its radiation resisting aptitude is estimated through various structural and elastic features. The results were interpreted due to the effect of TeO2 concentration in the glass systems. The observed molar volume (Vm) values reduced with the rise in the tellurium content with the creation of more bridging oxygens in the structure. The cross-link density rises the rigidity of the glass and its density. Additionally, boron-boron separation and tellurium-tellurium separation, and optical band gap were computed to prove the connectivity of the system which is noted to reduce with the rise in the tellurium content. Glass with 40% TeO2 is observed to hold high elastic moduli and consequently high density and connectivity which are vital requirements for effective radiation shielding. Moreover, the Monte Carlo N-Particle transport code version 5 is used to qualify the γ-ray shielding properties. The qualification of the shielding properties showed that the linear attenuation coefficient was enhanced by a factor of 80% from 0.248 cm−1 to 0.358 cm−1 by raising the TeO2 concentration between 0 and 40 wt %, respectively. The enhancement on linear attenuation coefficient was reflected on the half value thickness (Δ0.5, cm) and thickness equivalent (Δeq, cm) of the fabricated samples where Δ0.5 and Δeq values reduced with raising the TeO2 concentration between 0 and 40 wt %.

Radiation shielding performance of seawater-mixed concrete incorporating recycled coarse aggregate and steel slag

Concrete production entails a high amount of freshwater consumption. Moreover, as heavy-weight concrete production is cost-inefficient for mass structures, such as radiation shielding facilities, the need for seawater and other recycled/waste materials to produce sustainable concretes for radiation shielding applications cannot be overemphasized. Hence, this paper investigates the radiation shielding performance of fresh water and seawater-mixed concrete mixes produced using various waste coarse aggregates, including recycled aggregate and electric arc furnace steel slag (EAF-SS). Partial simultaneous replacements of the two coarse aggregate types are also considered. Aimed at addressing material sustainability, a total of ten such concrete mixtures were designed and produced by varying the type of mixing water with different combinations of the normal and waste coarse aggregates while maintaining the cement content and water/cement ratio constants. These mixtures were then tested for their unit weight, compressive strength, and nuclear radiation response through gamma-ray intensity detection. The mixes' compressive strengths ranged from 30.8 to 49.8 MPa, all of which met the specifications for structural concrete. Linear attenuation coefficients were computed based on the radiation experimental results for the different mixes. Three of the specimens passed the minimum requirement to be considered heavy-weight concretes. Regardless of concrete strength, the unit weight of the mixes and the type of water (fresh versus seawater) used for mixing had an impact on radiation shielding performance. The maximum compressive strength was attained in the fresh water-mixed concrete fully incorporating EAF-SS as coarse aggregate – 13% over that of the concrete with natural aggregate. Moreover, the use of EAF-SS enhanced the radiation shielding performance of concrete by 13–19%. Using local seawater improves radiation shielding by 4–5% while pursuing sustainable concrete production for nuclear applications. A mixture's unit weight and chemical composition – particularly the existence of hematite – are crucial factors in the effectiveness of radiation shielding. The variations in gamma-ray transmission reductions between mixtures confirm the feasibility of the materials utilized.

Simulation study on carbon-ion beam imaging by measuring secondary electron bremsstrahlung using imaging plate

The purpose of this study is to evaluate the effect of a lead radiation shield on the ability of a beam imaging device consist of an imaging plate (IP) and a collimator by Monte Carlo simulations. Simulations were performed using PHITS. A carbon-ion beam was injected to an acrylic target. A tungsten collimator having a pinhole was placed at the distance of 31.2 cm from the beam. A lead radiation shield was placed on the tungsten collimator. An IP was placed under the collimator. Beam images were acquired by recording the position distribution of energy deposition on the IP. We confirmed that therapeutic carbon-ion beam images could be acquired using the imaging device combining the IP and collimator. It was found that removal of the lead shield had no effect on the imaging results.