Exposure Buildup Factors Research Articles

Radiation protection efficiency of newly produced W-based alloys: Experimental and computational study

Tungsten based alloy is one of the materials which has great attention and can be used as gamma-ray shields, radiation source collimator, spallation neutron source target, plasma facing materials, etc. The motivation of the study is to produce new tungsten based alloys and determine the radiation protection characteristics of the alloys that can be used for radiation related applications. In this context, five tungsten based alloys (WxTayCr10Ni10Fe10Mo10) were produced and the dependence of radiation shielding ability on the changes in W and Ta concentration was investigated. The photon protection parameters such as linear attenuation coefficients, mass attenuation coefficients, effective atomic number, mean free path, half-value layer, exposure and energy absorption buildup factors, effective conductivity, effective electron number, atomic and electronic cross sections, and fast neutron removal cross-sections of the alloys were determined by Phy-X/PSD code. Additionally, XRD, EPR and SEM-EDS experimental results were evaluated for the investigation of spectroscopic characteristics. The crystallite sizes of the alloys were calculated by Debye-Scherrer method depending on the XRD phases in order to perform the structural characterization. It is concluded that a relationship exists between the crystallite size and photon attenuation. It may be stated that the increase in the amount of W improves the gamma radiation protection efficiency of the alloys. It is also seen that the fast neutron attenuation feature increases proportionally with W content. It is determined that the tungsten based alloys can be used as good radiation protection materials in radiation related applications.

Influence NiO on the structure, elastic properties and buildup factor of BaO-CdO-borosilicate glasses

In this work, the structure, elasticity parameters, and buildup factor of borosilicate glasses doped with BaO, CdO and NiO have been studied. Infrared (IR) spectroscopy was utilized to study the internal structure of the present system. IR spectra are broad, especially since the superposition between the borate and silicate occurs in the same spectral region. A deconvolution process was carried out to extract these spectra into their individual bands. The values of tetrahedrally-coordinated boron atoms ratio () barely increased from 37.9% for 1 mol% of NiO to 39.5% for 4 mol% of NiO. This increase indicates the transformation of three coordinated boron atoms () to four coordinated boron atoms () units with further NiO additions. The values were used along with the dissociation energies density and packing density parameters to calculate the elastic moduli; Young, shear, bulk, and Poisson ratio. The obtained values of Young’s modulus increase with further NiO additions. This increased behavior of Young’s modulus demonstrates the augmented ability of the current glasses to withstand variations in their length under lengthwise tensile tension or compression with further NiO additions. The rest of the elasticity moduli showed increased behaviors as well. These increased behaviors support the results obtained from structural properties analyses. An increment of BO4 units with decreasing the nonbridging oxygens ions (NBO) in the internal structure of present glasses produces an increase in the elastic parameters of these glasses. At photons energy of 0.2 MeV, the energy exposure buildup factor (EBF) values are low for glasses with a high concentration of CdO (low concentration of NiO), but the value of EBF is larger for glasses with a low concentration of CdO (high concentration of NiO).

Effects of WO3 reinforcement on the properties of poly(lactic acid) composites for radiation shielding

During this work, efforts have been made to improve the gamma radiation shielding capabilities of poly(lactic acid) (PLA) by including tungsten trioxide (WO3). Simulations and theoretical analyses have been performed on the parameters of radiation shielding. They have been tested across a broad spectrum of energies, from 0.015 to 15 MeV. The values suggest that naturally occurring composites with a high WO3 content may be utilized to improve the gamma shielding properties of PLA/TO (TO ≡ tungsten trioxide) composites for protection applications; such composites can be employed as a covering for the solar cells to prevent damage. The composite samples made of PLA and WO3 were analyzed for a range of photon energies. The results showed rise of considerable proportions in the values of linear attenuation coefficient (μ) and mass attenuation coefficient μm at 0.08 MeV, due to the k-absorption edge of tungsten. In addition, μ and μm for all samples at selected photon energy are increase as the WO3 content increases and decreases with increasing photon energy. The half value layer (T0.5) decreased as the WO3 content increased, with the highest values seen at 15 MeV and the lowest values at 15 keV. The behavior of the mean free path (λ) was identical to T0.5 with regards to the amount of WO3 and the energy of the photon. The T0.5 values of the PLA-W7 were lower than other polymer materials, making it a more efficient material for filtering radiation. The Zeff values of the PLA/TO composite samples were the highest at 0.08 MeV and showed a trend of increasing with energy to 15 MeV. The exposure buildup factor (EBF) and energy absorption buildup factor EABF values were computed using the G-P fitting method and showed that the lowest values were presented for the PLA-W7. An increase in WO3 reinforcement in the PLA sample contributed to the decreased EBF-EABF values. The shielding parameters were determined through calculations done using both Phy-X/PSD and FLUKA, and the results from both are in good agreement with each other. The results of the study demonstrate the effectiveness of PLA-W7 as a material for radiation shielding.

Development of Sustainable Radiation-Shielding Blend Using Natural Rubber/NBR, and Bismuth Filler

This research entailed the production of composite materials through the combination of natural rubber and acrylonitrile butadiene rubber, along with nano-silica-loaded bismuth (III) oxide, in varying concentrations ranging from 0 to 45 parts per hundred parts of rubber (phr). The gamma attenuation properties of the composites at different concentrations of Bi2O3 were measured. Additionally, the mechanical properties of the resulting composites, including hardness, tensile strength, and elongation, were tested. The composites with a concentration of 20 phr exhibited the highest tensile strength and elongation at break, followed by a subsequent decrease as the concentration of Bi2O3 increased. The gamma mass-attenuation coefficient of the composites increased as the Bi2O3 concentration increased from 0 to 45 phr, with values ranging from 0.083 to 0.090 cm2/g at 0.662 MeV. Moreover, the fast neutron mass removal cross-sections ranged from 0.092 to 0.072 cm2/g, corresponding to the variation of Bi2O3 concentration from 0–45 phr are also determined. Various parameters related to gamma-ray shielding, including the half-value layer, exposure build-up factor (EBF) up to 40 mean free path (mfp) penetration depth, and effective atomic number (Zeff) are also included. The radiation-induced aging of the prepared blend is tested by measuring the effect of radiation exposure on its shielding capability via its porosity change. The obtained results indicated that the prepared composites could be used for several radiation-protection applications.

Gamma ray attenuation behaviors and mechanism of boron rich slag/ epoxy resin shielding composites

Excellent thermal neutron absorption performance of boron expands the potential use of boron rich slag to prepare epoxy resin matrix nuclear shielding composites. However, shielding attenuation behaviors and mechanism of the composites against gamma rays are unclear. Based on the radiation protection theory, Phy-X/PSD, XCOM, and 60Co gamma ray source were integrated to obtain the shielding parameters of boron rich slag/epoxy resin composites at 0.015–15 MeV, which include mass attenuation coefficient (μt), linear attenuation coefficient (μ), half value thickness layer (HVL), electron density (Neff), effective atomic number (Zeff), exposure buildup factor (EBF) and exposure absorption buildup factor (EABF).μt, μ, HVL, Neff, Zeff, EBF and EABF are 0.02–7 cm2/g, 0.04–17 cm−1, 0.045–20 cm, 5–14, 3 × 1023–8 × 1023 electron/g, 0–2000, and 0–3500. Shielding performance is BS4, BS3, BS3, BS1 in descending order, but worse than ordinary concrete. μ and HVL of BS1-BS4 for 60Co gamma ray is 0.095–0.110 cm−1 and 6.3–7.2 cm. Shielding mechanism is main interactions for attenuation gamma ray by BS1-BS4 are elements with higher content or higher atomic number via Photoelectric Absorption at low energy range, and elements with higher content via Compton Scattering and Pair Production in Nuclear Field at middle and higher energy range.

Radiation shielding performance of metal oxides/EPDM rubber composites using Geant4 simulation and computational study

This paper aimed to evaluate the shielding performance of ethylene propylene diene monomer (EPDM) rubber composites filled with 200 phr of different metal oxides (either Al2O3, CuO, CdO, Gd2O3, or Bi2O3) as protective materials against gamma and neutron radiations. For this purpose, different shielding parameters, including the linear attenuation coefficient (μ), mass attenuation coefficient (μ/ρ), mean free path (MFP), half value layer (HVL), and tenth value layer (TVL), were calculated in the energy range between 0.015 and 15 MeV by using the Geant4 Monte Carlo simulation toolkit. The simulated μ/ρ values were validated by the XCOM software to examine the precision of the simulated results. The maximum relative deviation between the Geant4 simulation and XCOM was not greater than 1.41%, confirming the accuracy of the simulated results. Based on μ/ρ values, other significant shielding parameters such as effective atomic number (Zeff), effective electron density (Neff), equivalent atomic number (Zeq), and exposure buildup factor (EBF) were also computed to explore the potential usage of the proposed metal oxide/EPDM rubber composites as radiation protective materials. The study demonstrates that the gamma-radiation shielding performance of the proposed metal oxide/EPDM rubber composites are increasing in the order of EPDM < Al2O3/EPDM < CuO/EPDM < CdO/EPDM < Gd2O3/EPDM < Bi2O3/EPDM. Furthermore, three sudden increases in the shielding capability in some composites occur at 0.0267 MeV for CdO/EPDM, 0.0502 MeV for Gd2O3/EPDM, and 0.0905 MeV for Bi2O3/EPDM composites. This increase in the shielding performance is due to the K absorption edges of Cd, Gd, and Bi, respectively. Regarding the neutron shielding performance, the macroscopic effective removal cross-section for fast neutrons (ƩR) was evaluated for the investigated composites using MRCsC software. The highest ƩR is obtained for Al2O3/EPDM, while the lowest ƩR is obtained for EPDM rubber with no metal oxide content. According to the obtained results, the investigated metal oxide/EPDM rubber composites can be employed as comfortable clothing and gloves designed for workers in radiation facilities.

Gamma-rays buildup factor calculation using regression and Extra-Trees

The statistical fitting of existing data is an efficient method for calculating the gamma-ray buildup factors. However, the existing Geometric Progression (GP) fitting formula requires the interpolation of five parameters: a, b, c, d, and Xk. GP fitting formula also considers three factors: photon energy, shielding material and shielding in the interpolation process, leading to the complex calculations of buildup factor. On the other hand, the large and bloated parameter library also brings inconvenience to the application of GP formula in radiation calculation code. This paper proposes a regression method for calculating gamma-ray buildup factors based on Extra-Trees (ET). The training set is obtained from the exposure buildup factors of the ANS standard database to establish the ET with superior performance for buildup factor. The ET model can reproduce the data of exposure buildup factor in ANS without deviation. For materials not considered in ANS, the buildup factors calculated by ET model are consistent with the results calculated by GP fitting formula. The performance in time consumption is also satisfactory. The method proposed in this paper has the potential to replace GP fitting formula and be used in situations where the buildup factor needs to be calculated, such as design, shielding calculation and analysis of gamma-rays.

Estimating ECG intervals from a deep learning morphology model

The statistical fitting of existing data is an efficient method for calculating the gamma-ray buildup factors. However, the existing Geometric Progression (GP) fitting formula requires the interpolation of five parameters: a, b, c, d, and Xk. GP fitting formula also considers three factors: photon energy, shielding material and shielding in the interpolation process, leading to the complex calculations of buildup factor. On the other hand, the large and bloated parameter library also brings inconvenience to the application of GP formula in radiation calculation code. This paper proposes a regression method for calculating gamma-ray buildup factors based on Extra-Trees (ET). The training set is obtained from the exposure buildup factors of the ANS standard database to establish the ET with superior performance for buildup factor. The ET model can reproduce the data of exposure buildup factor in ANS without deviation. For materials not considered in ANS, the buildup factors calculated by ET model are consistent with the results calculated by GP fitting formula. The performance in time consumption is also satisfactory. The method proposed in this paper has the potential to replace GP fitting formula and be used in situations where the buildup factor needs to be calculated, such as design, shielding calculation and analysis of gamma-rays.

Elasto-mechanical and gamma radiation/neutron shielding effectiveness behavior of sodium metaphosphate glasses under different oxidization conditions: Effects of zircon ions

This repot aims to probe the physical, mechanical and radiation-protecting properties of a series of glasses with a chemical composition of yZrO2+(24.5-y)CaO+24.5Na2O+ 6P2O5+45B2O3 (0.5<y<5.0 mol%). The mechano-shielding characteristics of the glasses are discussed in terms of the molar ratio [ZrO2]/[CaO]. Glasses elastic-moduli are calculated utilizing the Makishima-Mackenzie model, along with Poisson's ratio (PR). The mass-attenuation-coefficient (MAC) of these samples is numerically evaluated in the energy range 0.015<E<15 MeV using the Phy-X/PSD online code. The computed MAC is used to derive significant radiation protection factors such as the linear attenuation coefficient (LAC), half-layer value (HVL), effective (Zeff)- and equivalent (Zeq) atomic number. The G-P fit method is employed to determine the exposure (EBF) and energy absorption (EABF) buildup factors for the glass set. Additionally, an assessment of the fast neutron removal cross-sections (ΣR) of the glasses is conducted. The study determined that the glass composition containing 5ZrO2–19.5CaO–24.5Na2O–6P2O5–45B2O3 (in mol%) demonstrated the most favorable properties for radiation protection implementations compared to the other glasses. Therefore, it can be inferred that the examined glasses demonstrate significant promise for protecting against radiation in both indoor and outdoor settings.

Estimation of neutron and gamma-ray attenuation characteristics of some ferrites: Geant4, FLUKA and WinXCom studies

Ferrites are ceramic oxide materials consisting of mainly iron oxide and they have become massively important materials commercially and technologically, having a multitude of uses and applications. The protection against neutron–gamma mixed radiation is crucial in several nuclear applications. From this standpoint, mass attenuation coefficient, radiation protection efficiency and transmission factor of some ferrites namely barium, strontium, manganese, copper and cadmium ferrite has been computed using Geant4 and FLUKA simulations. Based on the simulated mass attenuation coefficient, other significant parameters such as linear attenuation coefficient, effective atomic and electron number, conductivity, half value layer, and mean free path were calculated for the selected ferrite materials. The validation of Monte Carlo geometry has been provided by comparing the mass attenuation coefficient results with standard WinXCom data. Gamma ray exposure buildup factors were computed using geometric progression fitting formula for the chosen ferrites in the energy range 0.015–15 MeV at penetration depths up to 40 mfp. The findings of the present work reveal that among the studied ferrites, barium ferrite and copper ferrite possess superior gamma ray and fast neutron attenuation capability, respectively. The present work provides a comprehensive investigation of the selected iron oxides in the field of neutron and gamma ray.

Investigation of the effect of cement type on nuclear shield performance of heavy concrete

This article studies the radiation shielding performance of three different concrete-added samples. First, the mass attenuation coefficient values of three distinct concrete materials were computed using the MATLAB code at energies ranging from 0.015 to 15 MeV, and the findings obtained were verified by theoretical WinXcom results. Half-Value Layer (HVL), Tenth-Value Layer (TVL), Mean Free Path (MFP), Effective Atomic Number (Zeff), Exposure Build-Up Factor (EBF), Energy Absorption Build-Up Factor (EABF) are the variables computed to assess available concrete samples in terms of radiation attenuation characteristics. The results demonstrated that the concrete sample with CAC possesses better gamma-radiation shielding characteristics. Concrete samples’ removal cross-sections (∑R) were obtained to analyze their ability to stop fast neutrons. Iron, aluminum, and lead-added concretes are better in terms of their density than the other types of concretes. Given the relationship between the density of the material and neutron shielding propensities, iron, aluminum, and lead-added materials are expected to better serve for shielding purposes. SRIM Monte Carlo code, as it is standard, was utilized to compute the mass stopping power (MSP) and projection range (PR) values. The concrete sample with CAC has shown better shielding properties compared to the others in the sample of the concretes having the lowest HVL, TVL, and MFP and highest ∑R. For proton and alpha particles, the concrete sample with CAC sample shows the best radiation shielding and protection properties. The concretes selected for the study are useful for shielding purposes compared to many other materials used in industry. In addition, radiation shielding concrete is cheaper than other shielding materials. It is easier to mold into different geometric shapes and is suitable for shielding from protons or alpha particles. Among the different concretes investigated in this study, it can be used for structures such as radiation oncology and nuclear medicine clinics in hospitals. Additionally, it can act as a biological shield for nuclear power plants, particle accelerators, and radionuclide laboratories, as well as other sources of radiation.

Graphene-bioactive glass composites: Structural, Vickers hardness, and gamma-ray attenuation characteristics

Introduction: Graphene-based materials have gained increasing attention for use in radiation attenuation applications. In this study, pristine graphene nanoplatelet-containing (1, 3, 5, and 10 wt%) borate-based bioactive glass composites were prepared.Methods: Structural properties, Vickers microhardness, and gamma-ray radiation shielding properties of the fabricated composites were examined in detail.Results and Discussion: Results revealed that the inclusion of the graphene in the glass matrix led to a decrease in the bulk density of the glass-based composites from 2.41 to 2.31 g/cm3. Similarly, a decrease in Vickers hardness was obtained as the graphene concentration was increased due to a convoluted effect of the non-uniform distribution of graphene nanoplatelets in the bioactive glass matrix and the higher residual porosity. Vickers hardness of the bare and the 10 wt% graphene-containing bioactive glass discs were measured to be 5.03 ± 0.28 GPa and 1.87 ± 0.56 GPa, respectively. On the other hand, the incorporation of graphene starting from 3 wt% decreased the crack propagation after indentation which may be attributed to an increase in fracture toughness. In the study, fundamental gamma ray absorption properties of graphene-containing bioactive glasses were examined in the 0.015–15 MeV incident photon energy range. For this purpose, the Py-MLBUF code was employed to determine gamma ray absorption parameters. Results showed that linear attenuation coefficients of the glass-based composites decreased due to a decrease in the density of the samples. On the other hand, as graphene was incorporated into the bioactive glass structure, exposure buildup factor and energy absorption buildup factor values increased. The growing graphene ratio in the glass structure contributed negatively to the photon’s tendency to interact with the material.

Investigation of the mechanical properties, shielding parameters and flux distribution in borate - Based glass system using PHITS code; a simulation study

A descriptive method for the attenuation and spatial distribution of flux of photons and fast neutrons for 20Bi2O3 − xPbO − (80 − 2x) B2O3 − xGeO2 (x = 5, 10, 20 and 30 mol %) glass systems (coded as S1, S2, S3, S4 respectively) were performed using PHITS code. The calculated elastic moduli, Young modulus, EM was ranged between 32.58 and 33.81 GPa, while bulk KM and shear GM moduli were in the range of 23.36–30.45 and 12.32–13.15 GPa, respectively. However longitudinal modulus LM was between 40.89 and 46.89 GPa. The spatial distribution of the transmitted photon flux showed a decrease with increasing Pb and Ge concentrations. The mass attenuation coefficients, μm were found to be 70.755–0.042, 76.160–0.043, 83.378–0.046 and 91.895–0.047 cm2/g for S1, S2, S3 and S4 respectively in the energy range of 0.015–15 MeV. The Half Value Layer (HVL) and mean free path (MFP) values were registered in the order of S4 < S3 < S2 < S1. At low energy, the exposure buildup factor EBF of the glasses recorded decrease by the substitution of B2O3 by PbO and GeO2 contents. At energy 0.15 MeV, a crossed behavior was noticed. However, at high energy the inverse behavior of EBF was observed. The neutron transmitted flux percentages, at thickness 10 cm were in the range of 10.26–15.51% at all the selected energies. The linear absorption coefficients ΣT, ranged between 0.220 and 0.278 cm−1 which indicated that S4 represents the best shielding capacity among all. The overall results of this work assessed the selected glasses potential for use as gamma and fast neutron radiation shielding products.

Mechanical properties, elastic moduli, and gamma ray attenuation competencies of some TeO2–WO3–GdF3 glasses: Tailoring WO3–GdF3 substitution toward optimum behavioral state range

Abstract We report the mechanical properties, elastic moduli, and gamma ray attenuation properties of some TeO2–WO3–GdF3 glasses. Using the chemical composition of the selected glasses, the dissociation energy per unit volume (G t ) and the packing density (V t ) were calculated. Using the G t and V t values, Young’s, Shear, Bulk, Longitudinal Modulus, and Poisson’s ratio of the glasses are calculated. Next several fundamental gamma ray attenuation properties such as linear and mass attenuation coefficients, half value layer, mean free path, effective atomic number, effective electron density, effective conductivity, exposure, and energy absorption buildup factors are calculated in 0.015–15 MeV energy range. As a consequence of WO3–GdF3 substitution, the glass densities are observed in different values. The overall gamma ray attenuation properties are found to be enhanced through WO3 addition. Moreover, the increasing WO3 incorporation into glass configuration decreases the overall elastic moduli of glasses. It can be concluded that increasing WO3 may be a useful tool for enhancing the gamma ray attenuation qualities and decreasing the elastic moduli of TeO2–WO3–GdF3 in situations where a material with versatile mechanical properties is required.

Translocation of tungsten(vi) oxide/gadolinium(iii) fluoride in tellurite glasses towards improvement of gamma-ray attenuation features in high-density glass shields

Abstract This study investigates the effect of substituting tungsten(vi) oxide/gadolinium(iii) fluoride in tellurite glasses whose densities varies from 5.0879 to 5.3246 g/cm3 on gamma-ray absorption properties. A range of fundamental absorption parameters, including attenuation coefficients, half-value layer thicknesses, effective atom and electron numbers, effective conductivity, exposure, and energy absorption buildup factors, were studied for five different glass samples with varying substitution ratios. The ratio of tungsten(vi) oxide to gadolinium(iii) fluoride varied between 0 and 20 mol%, as well as the TeO2 ratio in the composition was maintained between 90 and 80 mol%. The sample with the composition of 80–20 mol% TeO2/WO3, which attained the maximum density value with 20 mol% WO3 addition, showed the highest gamma-absorption capabilities based on the obtained findings in the range of 0.015–15 MeV. In consideration of the mechanical and physical properties of WO3 in tellurite glasses, it can be concluded that WO3 incorporation is a crucial monotonic process that may be utilized to further improve the properties of glass shields.

Theoretical Investigation of the Gamma and Neutron Interaction Parameters of Some Inorganic Scintillators Using Phy-X/PSD and NGCal Software

AbstractInorganic scintillators are used in extreme environments and are essential in applications such as nuclear fission and fusion, radiation therapy, marine, and space exploration, etc. Radiation resistance is required for inorganic scintillators to be used in above mentioned applications. It is important to calculate the gamma buildup factors for inorganic scintillators to understand their radiation resistance behavior. The gamma-ray and neutron interaction parameters were calculated for inorganic scintillators such as BaF2, BGO, CdWO4, CaF2(Eu), CaWO4, CsI, CsI(Na), CsI(Tl), Gd2O2S, LaBr3(Ce), LaCl3(Ce), PbWO4, LSO(Ce), LYSO(Ce), NaI(Tl), YAG(Ce), ZnS(Ag), ZnWO4. The gamma-ray interaction parameters such as mass attenuation coefficient, half value layer, tenth value layer, effective atomic number, equivalent atomic number, exposure buildup factor (EBF), and energy absorption buildup factor (EABF) were computed using Phy-X/PSD software. The neutron interaction parameters such as fast neutron removal cross section, and mass attenuation factor for thermal and fast neutron were computed using Phy-X/PSD and NGCal software, respectively. The present calculated mass attenuation coefficient values are compared with GEANT4 code data available in the literature. The higher values of Zeff were found for PbWO4 up to 0.1 MeV and above 0.1 MeV, CsI(Tl) has higher Zeff values. However, the Zeq values were found to be higher for PbWO4 in the whole energy range. The mass attenuation factor for thermal and fast neutrons with the highest value was found for Gd2O2S and with the lowest value for BGO. The present investigation indicates that the inorganic scintillator PbWO4 has an excellent gamma-ray sensing response.

Assessment on gamma radiation shielding properties of molybdenum doped bricks

Gamma radiation permeability experiments were carried out by preparing a new type of brick mixture with Molybdenum (Mo, Z = 42) additives (0 (B0), 5 (B1), 10 (B2), 20 (B3), 30 (B4), 40 (B5), 50 (B6) %wt). The density of the bricks increased to 2.79 g/cm3 with increasing Mo content. The bricks were exposed to gamma rays with 81, 276, 303, 356 and 383 keV photon energies emitted from 133Ba radioactive source and the transmitted intensities were detected using the Canberra Ultra Ge detector. Gamma attenuation characteristics of the bricks were also calculated by mass attenuation coefficients, effective atomic numbers and electron densities using the EpiXS program as a function of gamma-ray energy. And also, the exposure and energy absorption buildup factors of bricks were determined at different mean-free paths and photon energies using EpiXS program. It was observed that as the density of the bricks increased, the radiation shielding properties also increased. The values of the mass attenuation coefficients at 81 keV for B0–B6 bricks were found to vary between 0.229 and 1.08 cm2/g. It was found that Zeff values were 13.3, 16.1, 17.4, 19.09, 22.5, 25.3 and 26.6 for B0, B1, B2, B3, B4, B5 and B6 samples at 81 keV, respectively. As can be seen from these results, B6 brick has the highest Zeff value. And also, the calculated results displayed that the lowest values of exposure buildup factors and energy absorption buildup factors are observed for the B6 brick. The B6 brick containing 50% Mo element has a higher mass attenuation coefficient and effective atomic number values than the other bricks. The values of exposure and energy absorption buildup factors of B6 brick were lower than the values of other investigated samples. The measured and calculated shielding values of the bricks were in close agreement. It has been seen that the shielding results of these new types of bricks, which are low in cost and easy to produce and use, are quite successful.

Gamma Attenuation Features of White Cement Mortars Reinforced by Micro/Nano Bi2O3 Particles.

This study aims to explore the radiation protection properties of white mortars based on white cement as a binder and Bi2O3 micro and nanoparticles in proportions of 15 and 30% by weight as replacement sand. The average particle size of micro- and nano-Bi2O3 was measured using a transmission electron microscope (TEM). The cross-sectional morphology and distribution of Bi2O3 within the samples can be obtained by scanning electron microscopy (SEM), showing that nanoscale Bi2O3 particles have a more homogeneous distribution within the samples than microscale Bi2O3 particles. The shielding parameters of the proposed mortars were measured using the HPGe detector at various γ-ray energies emitted by standard radioactive point sources 241Am, 133Ba, 60Co, 137Cs, and 152Eu. The experimental values of the prepared mortars' mass attenuation coefficients (MAC) match well with those determined theoretically from the XCOM database. Other shielding parameters, including half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective electron density (Neff), effective atomic number (Zeff), equivalent atomic number (Zeq), and exposure buildup factor (EBF), were also determined at different photon energies to provide more shielding information about the penetration of gamma radiation into the selected mortars. The obtained results indicated that the sample containing 30% by weight of nano Bi2O3 has the largest attenuation coefficient value. Furthermore, the results show that the sample with a high concentration of Bi2O3 has the highest equivalent atomic numbers and the lowest HVL, TVL, MFP, and EBF values. Finally, it can be concluded that Bi2O3 nanoparticles have higher efficiency and protection compared to microparticles, especially at lower gamma-ray energies.

Effect of Ce-dopant on photon interaction parameters of zirconolite-based borosilicate glass ceramics

In the present investigation, 70 wt% of zirconolite (CaZr1-xCexTi2O7, x = 0, 0.2, 0.4, 0.6, 0.8 and 1) and 30 wt% of sodium borosilicate glass (NaB0.5Al0.5Si2O6) (sample C0 to C10) have been synthesized. The photon interaction parameters viz. mass attenuation coefficient, effective atomic number, effective electron density, mean free path, and half value layer have been investigated for glass-ceramic samples at incident photon energies of 59.58 keV, 81.2 keV, 356 keV, 662 keV, 1173 keV and 1333 keV. Furthermore, effective neutron removal cross-section values, mass stopping power (MSP) and range of alpha particles and proton, were also calculated using SRIM codes. Moreover, gamma-ray energy absorption buildup factor (EABF) and exposure buildup factor (EBF) were also estimated. The experimental results are in agreement with the theoretically calculated values using WinXCOM program. Among the given prepared samples, C10 shows the best shielding properties, and C0 shows the best capability for neutron absorption. The MSP and projected range of α-particles and protons in all the prepared samples show very small variation with the change of Ce content in zirconolite in the energy range upto 15 MeV. The measured values are extensively desirable in fission and fusion reactors, medical applications, shielding researchers, and radiation physics.

Enhancing the Gamma-Radiation-Shielding Properties of Gypsum–Lime–Waste Marble Mortars by Incorporating Micro- and Nano-PbO Particles

In the current study, the gamma-radiation-shielding characteristics of novel gypsum-lime-waste marble-based mortars reinforced with micro-PbO and nano-PbO powders were investigated. In total, seven mortar groups, including a control mortar (named GLM), were prepared. The other groups contained10, 20, and 30 wt.% of both micro-PbO and nano-PbO as a waste marble replacement. This study aimed to explore the effect of particle size and concentrations of PbO powders on the γ-ray-shielding capability of GLM mortars. For this purpose, an HPGe detector and five standard radioactive point sources (241Am, 133Ba, 137Cs, 60Co, and 152Eu) were employed to measure different shielding parameters, including the linear attenuation coefficient (μ), mass attenuation coefficient (μm), mean free path (MFP), half-value layer (HVL), and tenth-value layer (TVL), for the prepared samples in the energy range between 59.53 keV to 1408.01 keV. On the basis of μm values, other significant shielding parameters such as effective atomic number (Zeff), effective electron density (Neff), equivalent atomic number (Zeq), and exposure buildup factor (EBF) were also computed to explore the potential usage of the proposed mortars as radiation protective materials. The results reported that the smallest HVL, TVL, and MPF, as well as the largest attenuation values, were obtained for mortars reinforced by nano-PbO compared to those containing micro-PbO. It can be concluded from the results that the mortar samples containing nano-PbO had a remarkably improved gamma-radiation-shielding ability. Thus, these mortars can be used for radiation shielding on walls in nuclear facilities to reduce the transmitted radiation dose.