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A novel shielding material prepared from solid waste containing lead for gamma ray
Abstract
Human beings are continuously exposed to cosmogenic radiation and its products in the atmosphere from naturally occurring radioactive materials (NORM) within Earth, their bodies, houses and foods. Especially, for the radiation protection environments where high ionizing radiation levels appear should be shielded. Generally, different materials are used for the radiation shielding in different areas and for different situations. In this study, a novel shielding material produced by a metallurgical solid waste containing lead was analyzed as shielding material for gamma radiation. The photon total mass attenuation coefficients (μ/ρ) were measured and calculated using WinXCom computer code for the novel shielding material, concrete and lead. Theoretical and experimental values of total mass attenuation coefficient of the each studied sample were compared. Consequently, a new shielding material prepared from the solid waste containing lead could be preferred for buildings as shielding materials against gamma radiation.
... Several researches were established concerning the developing of concrete characteristics to be adequate with shielding requirements employing various geometries and nuclear radiation sources [2][3][4][5][6][7][8]. Wasan et al. [9] investigate the adequacy of adopting reactive powder concrete (mixed of cement, sand of zone 4 gradation, silica fume, superplasticizer and water) in protective erections by measuring linear and mass attenuation coefficient using gamma ray and beta particles of varies energies. ...
... The irradiation was carried out for (1-6) days with dose rate of 2 mSv/hr or 4 rad/day. After being exposed to the adopted period of gamma ray effect (1)(2)(3)(4)(5)(6) days, each cube was tested using concrete test press machine, Fig. 1, to assess the compressive strength of the examined cube. ...
Reactive Powder Concrete (RPC) could be considered as the furthermost significant modern high compressive strength concrete. In this study, an experimental investigation on the impact of micro steel fiber volume fraction ratio and gamma ray irradiation duration influence upon the compressive strength of RPC is presented. Three volume fraction ratios (0.0, 1.0 and 1.5) % was implemented. For each percentage of the adopted fiber ratios, six different irradiation duration was considered; these are (1, 2, 3, 4, 5 and 6) days. Gamma source (Cs-137) of energy (0.662) MeV and activity (6) mci was used. In a case of zero volume fraction ratio, the experimental results showed that gamma ray had a significant influence on the reducing of the compressive strength varies between (1.2-8.6) % for a period of (1-6) days, respectively. Although there was a decrease in the compressive strength for a state of non-zero volume fraction ratio (1 and 1.5) % varies between (1.0-3.1 and 0.4-1.6) %, respectively, the attained results indicated that gamma ray had no significant effect to reduce the compressive strength of the RPC that's included micro steel fibers as a volume fraction.
... Aside from that, foundation shielding materials can be made of heavy, dense metals like steel (Fe), tungsten (W), and bismuth (Bi). In spite of this, Pb and Cd continue to be the most often used base materials due to their high atomic weight, high density, inexpensive maintenance, and great mass attenuation [17]. ...
The study investigated new nanocomposites’ γ-ray and neutron shielding properties based on raw attapulgite, a clay matrix intercalated with different weight percentages of mixed nano metal oxides CdO and PbO. The various percentages were as follows: (100–2x)% Attapulgite + x%CdO + x%PbO, abbreviated as (AT100–2x CdxPb x ), where x = 5, 10, 15%. The nanocomposites were characterized using XRD, FTIR, and EDX, confirming their successful preparation. SEM images revealed that the mixed oxide nanoparticles were successfully intercalated into the layers of attapulgite clay, with an average particle size of approximately 31.46 nm. The bulk densities of the prepared nanocomposites were measured to be in the range of 2.034 to 2.555 g/cm³. GEANT4 simulations were employed to evaluate the nanocomposites’ γ-ray and neutron shielding performance in the photon energy range of 0.015 to 15 MeV. Phys-X code was used for verification. The simulation results showed a maximum difference of approximately 9.5% between GEANT4 and Phys-X predictions. To assess the γ-ray shielding performance, various shielding parameters were calculated at selected photon energies. The μ m values ranged from 4.589 to 0.020 cm².g⁻¹, 6.311 to 0.021 cm².g⁻¹, 8.350 to 0.022 cm².g⁻¹ and 10.804 to 0.023 cm².g⁻¹ for raw attapulgite, AT90Pb5Cd5, AT80Pb10Cd10, AT70Pb15Cd15 across the photon energy range. The AT70Pb15Cd15 nanocomposite exhibited the highest μ m , Z eff , Z eq , and the lowest T 1/2, T 1/10, and MFP values. Notably, it also demonstrated the highest FNRCS (approximately 0.1 cm⁻¹). These findings suggest that clay-based nanocomposites represent a new class of low-cost, locally available advanced materials with potential applications in γ-ray and neutron shielding characteristics.
... The spectra obtained using these radioisotopes were analyzed with MAESTRO-32 spectroscopy software. Studies investigating the radiationshielding properties of many different materials using the NaI(Tl) gamma spectroscopy system and similar experiment systems were reported in the literature [25][26][27]. ...
In recent years, the scientific community has spent significant effort exploring radiation-shielding glass materials. The present work was conducted by synthesizing a glass series of 20La 2 O–10BaO –15Na 2 O–(55− x )SiO 2 – x Bi 2 O 3 , x : 0, 5, 15, and 25 wt%. After producing the samples, in-depth studies were performed on the physical, optical, thermal, and radiation attenuation properties of the fabricated glass series. A radical color change from nearly neutral to dark-brown color occurred as Bi 2 O 3 entered the glass network. The density values equaled 2.8324, 2.9511, 3.0992, and 3.3657 g cm ⁻³ for LBSS1 to LBSS4 samples, respectively. According to XRD patterns, neither sharp nor moderate peaks developed; a hump-like formation between 20 and 35 degrees was visible in all glass samples. FTIR measurement revealed transmission as a function of varying wavenumber from 4000 to 400 cm ⁻¹ for the prepared glass specimens, and different bond types were noted. The UV–Vis technique removes it displayed that increasing Bi 2 O 3 content blocked light transmission throughout the glass medium. The radiation-shielding parameters of linear attenuation coefficient (LAC), mass attenuation coefficient, transmission factor, and half value layer were calculated with experimental and MC simulation methods for all glass samples at six different energies between 356 and 1332 keV. The results were compared with the Phy-X database, and good agreement was obtained. The highest LACs were obtained at the lowest energy (356 keV) with values of 0.3108, 0.3455, 0.4471, and 0.5486 cm ⁻¹ for LBSS1, LBSS2, LBSS3, and LBSS4 glasses, respectively. The photon attenuation ability of the LBSS glasses increased by increasing the Bi 2 O 3 ratio, especially at low energies. Therefore, the authors can conclude that future applications, such as observation window in CT rooms, may efficiently exploit LBBS4 glass system.
... In addition to being eco-friendly, locally available, and low-cost, the properties of suitable radiation-shielding material include its capacity to attenuate radiation, durability, moldability, fire resistance, and heat and moisture insulation (Gili and Hila 2021). There are numerous shielding materials to choose from, but the most popular media are lead-based (Singh et al. 2004;Erdem et al. 2010;Rezaei-Ochbelagh and Azimkhani 2012;Singh et al. 2015). Lead's effectiveness in blocking radiation is attributed to its high density and high atomic number. ...
Ionizing radiation poses a major risk to industrial, medical, and radiological systems, as well as the nuclear power sector. Radiation must be contained to avoid harming radiation workers. The use of appropriate shielding material must be observed. In this study, various historical lime mortars from Spanish colonial structures in the Philippines are investigated for their unique radiation shielding characteristics. These include [i] mortar samples from the foundational ruins of the former San Francisco Church in Intramuros, Manila (INT); [ii] joint mortar from Fort Almonte in Bacolod, Lanao del Norte (LDN); [iii] mortar from the ruins of a 19th century Roman Catholic Church in Manila (MNL); iv) wall plaster from a 19th century Loboc Church convent in Bohol (LOB); and v) church debris mortar of Baclayon Church in Bohol (BAC). For reference, self-compacting concrete (SCC) was also analyzed. The best radiation shielding for X-ray, low, and high gamma-ray energies appears to be the BAC because it has the highest mass attenuation coefficient (MAC) from energies between 5-500 keV and above 3000 keV. The second-highest MAC is that of LOB, which is almost identical to the MAC of the SCC. The MNL has the lowest MAC, as it lacks a significant number of high atomic number elements, which is present in other historical lime mortars. The fact that BAC has the highest effective atomic number (Z eff) for all photon energies from 1-10 6 keV suggests that it is the best historical lime mortar for shielding against photon radiation. The BAC has the lowest energy absorption (EABF) and exposure (EBF) buildup factors for all photon energies, indicating that it is the best lime mortar for photon radiation shielding. EABF and EBF for historical lime mortars are as follows: BAC < SCC < LOB < LDN < INT < MNL.
... Exposure to gamma radiation can cause serious health issues (Hurem et al., 2018). Hence, to deal with the gamma radiations, a shielding material with a high atomic number and high density is used such as lead, concrete, steel, etc. (Erdem et al., 2010;RWASHDI et al., 2022;Waly and Bourham, 2015). Despite lead's many advantages like low cost, high density, and excellent shielding ability, it has some negative effects on the human health (Hegazy et al., 2021a;Malidarre et al., 2023) as well as on the environment. ...
Conventional gamma radiation shielding materials, such as lead and lead-based composites are heavy and hazardous to human health and the environment. This particular aspect has prompted research into alternative shielding materials. The key objective of this work is to investigate Bismuth Oxide and unsaturated polyester resin (UPR)-based polymer composite material as a radiation shielding. The investigation used a gamma spectrometer consisting of an HPGe detector and the radioactive point sources 60Co, 133Ba, and 137Cs that have energies ranging from 81 keV to 1332 keV for experimentally evaluating mass attenuation coefficient (MAC). Subsequently, the experimental results for MAC were compared with the corresponding values obtained from WinXCOM and Geant4 simulation. Our findings indicated that the mass attenuation coefficient values of experimentally investigated composites align well with the theoretical and simulated values. In addition, we examined the half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and radiation protection efficiency (RPE) parameters. From the study, it can be inferred that lead (Pb) can be replaced by UPR+50 wt % Bi2O3 composite for low-energy gamma-ray shielding applications.
... Recently, and thanks to advances in composite materials, interest has been aroused in using steel chips as a reinforcing agent in concrete, improving the mechanical properties of concrete and giving steel chips a new purpose [4,5,6]. Additionally, the use of concrete reinforced with steel chips for the construction of nuclear reactors, clinics, and bunkers is being studied due to the recent discoveries of the gamma radiation absorption properties of these concretes reinforced with steel chips [4,7,8]. ...
This work is an experimental and numerical study of the flexural strength increase in concrete with steel chips as reinforcement. The concrete was reinforced with different thicknesses of AISI 4140 steel chips: 1.0, 1.5, 2.0, and 2.5 mm, respectively. The metal chip replaced the sand in different percentages: 0 %, 15 %, 25 %, and 50 %. A two-level factor analysis was carried out to study the effect of metal chip thicknesses and their percentages on the flexural strength, making 13 different samples. Flexural tests were carried out in triplicate, making 39 tests. The 39 samples were weighed and measured. Flexural tests, the weights, and the measurements showed that the modulus of rupture and the density increase with the metal chip thicknesses and with its percentage from 2.20 to 2.55 g/cm3 and from 4.6 to 8.6 MPa, respectively. Numerical studies made by the Finite Element Method using Calculix® showed that the concrete can be simulated as an elastic isotropic material where the Youngs Modulus can be supposed equal to the Flexural Modulus, except in the cracking zone of the concrete, where its behavior is not linear. Flexural tests and numerical studies showed that the mechanical behavior of concrete does not change significantly at the elastic zone, but after the elastic zone, when beginning the microcracking, the effect of metal chips as reinforcement agents is noticeable. The increase in flexural strength of the concrete due to the metal chips is noticeable after the first micro-cracks appear in the specimen.
... This difference can be attributed to the higher colemanite content in mixture A, which results in an elevated boron element concentration. This affects the concrete's hydration process, weakens the bonding structure, reduces homogeneity, and increases porosity compared to other samples [12]. ...
... The following Eq 1 may be used to get the linear attenuation coefficients (μ) from the thicknesses of the material [18,19]: (1) where No is a gamma ray incident, N is the attenuation of the gamma rays and x is the thickness of the sample. ...
This study looks at the synthesis of innovative PEO/PVA/SrTiO3/NiO nanocomposites for piezoelectric sensors and gamma shielding applications that are low weight, elastic, affordable and have good gamma ray attenuation coefficients. The impact of SrTiO3/NiO on the structural characteristics of the PEO/PVA mixture is investigated. The polymer mixture PEO/PVA received additions of SrTiO3/NiO at concentrations of (0, 1, 2, 3 and 4) weight percent by the casting method. On the top surface of the films PEO/PVA/SrTiO3/NiO NCs, scanning electron microscopy reveals several randomly distributed aggregates or fragments that are consistent and coherent. An optical microscope image collection reveals that the blend’s additive distribution of NPs was homogenous. Gamma ray shielding application results show that the attenuation coefficient of PVA/PEO/SrTiO3/NiO NCs is increased by increasing concentration of SrTiO3/NiO nanoparticles. Radiation protection is another application for it. The pressure sensor application findings of NCs show that, when the applied pressure rises, electrical capacitance (Cp) increase.
... Polymer composites have been widely used as an excellent material in place of traditional materials such as steel, concrete, and lead. To overcome the disadvantages of lead and concrete, researchers are promoting new types of protective substances that are lead-free, inexpensive, resilient, and efficient in absorbing gamma photons via the integration of inorganic particles in polymers [12][13][14][15]. ...
... As it is clear that climate change has already begun, and therefore some must take action to prevent catastrophic conclusions. With these motivations, solid waste substances-based material systems can appear as an alternative solution for many applications including radiation shielding [6]. Instead of utilizing primary resources, one can use waste materials to obtain similar properties to those composed of primary raw materials provide. ...
... High-energy radiations like X-rays and gamma rays have had their energy reduced using lead and other high Z materials. On the other hand, high Z elements might not always be able to filter out all kinds of radiation, especially neutron particle emissions from space or nuclear reactors [5][6][7][8]. ...
Today, with the development of technology, different kinds of materials are being tested to increase the quality, efficiency and reliability of the materials used in the fields of space and aviation, computers, energy and health. In this direction, materials scientists and researchers from different disciplines make multidimensional analyzes and reveal the use of basic building materials in the technological field through both prototypes and simulation methods. In this way, it will be possible to use materials that can give better results than the materials currently used. In this study, polydimethylsiloxane C2H6OSi (PDMS) was prepared using zinc oxide nano powder additions according to the PDMS(ZnO) x formula, where (x=0, 2.5, 5, 7.5, 10, 15 mol %). UV–VIS spectroscopy was performed on the examined PDMS-PDMS(ZnO)15 samples to estimate their optical properties. Transmission spectra demonstrate that the λcutoff wavelength and color of the PDMS-PDMS(ZnO)15 polymer samples both changed to a longer wavelength when ZnO concentration increased (stronger White). Additionally, FTIR analysis of samples were performed. Due to the physical blending of the nanoparticles with the polymeric matrix, the FTIR Spectra of the PDMS with ZnO nanoparticle samples demonstrate that no new peaks were discovered. The mass attenuation coefficient μm of the prepared samples was calculated using the MCNP N-Particle Monte Carlo code and WinXCOM. It was discovered that the theoretical and simulation results were quite close. The addition of ZnO nanoparticles to the PDMS (ZnO) samples increased μm values. The PDMS(ZnO)15 polymer sample showed the lowest HVL, MFP, and TVL values of all the polymer samples due to its high ZnO content. It was included that the PDMS(ZnO)15 is an effective promising material that could be used against gamma-radiation.
... Several studies have been conducted to understand the applications of concrete in nuclear power plants and installations related to radioactive materials considering its structural and protective properties [20][21][22][23]. Some of the heavyweight concrete incorporating different fillers in various radiation applications are given in the Table 1. ...
Concrete with fillers can serve as a shielding material against harmful radiation effects due to availability of materials, low cost, high strength, and adaptability in various environments. An overview of the recent developments in concrete as a gamma ray shielding material, along with important aspects of aggregates in various nuclear isotope applications is presented
... Several experimental and theoretical studies have documented the use of a range of shielding materials, including concrete, polymer composites, and heavy metals such as lead and lead oxide/tungsten/tin composites, to attenuate or absorb harmful radiation (El-Sayed Abdo et al., 2003;Zeitlin et al., 2006). The type of radiation involved and the spectrum of radiation-related energies affect the shielding efficacy of the material (Erdem et al., 2010;Clegg et al., 2019). ...
Radiation shielding material is essential to protect humans and the environment from direct exposure to ionizing radiation. The ionizing radiation is best absorbed by high-density materials and heavy atoms like lead. The drawback of lead is that it is toxic, heavy, non-transparent, and bulky, which are often undesirable features for most applications. As a result, while the development of nanomaterials as radiation shielding materials is a promising field of study, a complete evaluation of the application of tungsten carbide nanofilm as a lead-free shielding material is still lacking in the literature. Tungsten carbide is an attractive material because it can be formed into a film using various fabrication processes suitable for a wide range of substrates. Moreover, tungsten carbide has a high atomic number, greater density, and better shielding characteristics compared to lead. Therefore, the purpose of this review was to provide recent advancements in the physical properties of tungsten carbide, the application of tungsten carbide nanofilm as radiation shielding material, and an overview of thin film deposition and deposition techniques that include the morphological structure of tungsten carbide nanofilm. The key challenges and future direction are also discussed.
... Some previous works in the field of radiation shielding were done and published using different shield materials, different geometries and different nuclear radiation sources [4][5][6][7][8][9][10][11][12]. ...
This paper presents values for density, linear attenuation coefficient and mass attenuation coefficient experimentally in addition to theoretically by using X-Com program (Version 3.1), of Portland cement without and with different percentages of iron slag by weight (5%, 15%, 25%, 35% and 45%). Measurements were carried out using a collimated beam of gamma ray from point sources (Co-60, Cs-137, and Na-22) , and sodium iodide (1.5\\X1.5\\) crystal with cassy-gamma ray spectrometer. From the experimental results, it was found that the mass attenuation coefficients have been increased with increasing the addition of iron slag, in addition the theoretical calculation of mass attenuation coefficient. It is also found that there are deviation between experimental values and theoretical calculation for all cement samples this is due to the experimental errors.
... When a beam of X-or gamma-rays passes through the material there is attenuation. The Beer-Lambert law defines the attenuation by absorption or diffusion (42)(43)(44)(45)(46). This Menu-based X-LAB Pro software for control of spectrometer functions and for evaluation of data: XRF Analyser Pro exponential relationship between the ratios of transmitted photon intensity to that of the incident photon, also called transmittance is calculated using the following equation ...
This study used the Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry to determine the elemental composition of nineteen rock samples from the Pouma sub-division of Cameroon. The major chemical elements found in these samples were compounds of SiO2, Al2O3, K2O, Fe2O3, CaO, and P2O5. The elemental characterization of the investigated samples was used to evaluate the mass attenuation coefficients of the quartzite rocks using the XCOM analytical calculation software and the GEANT4 Monte Carlo computational toolkit. The mass attenuation coefficients were calculated for the average concentration values of the samples from different sampling sites. The mass attenuation coefficients generated using the GEANT4 simulation have uncertainties less than 4% in all the four investigated sampling sites compared to the analytical results. The results of the simulation showed that the calculated mass attenuation coefficients are in good agreement with the theoretical data. Therefore, the developed GEANT4 code for radiation properties assessment of rocks is accurate and could be used by scientists worldwide. The determination of these mass attenuation coefficients is consequently the unveiling of radiation shielding properties of the investigated material.
... Therefore, radiation shields that absorb incoming photons and reduce radiation levels to acceptable levels are commonly employed to protect living things from these potentially harmful side effects. For this purpose, lead-based compounds [6,7], concrete [8,9], some alloys [10,11] and natural stones [12] are commonly employed for this purpose. Granite is a natural stone having wide range applications mainly in the construction industry [13,14]. ...
In this study, physical, chemical, structural and radiation attenuation properties of some granite samples collected from Kütahya-Simav and İzmir (Bergama and Karaburun) were investigated. The true particle density of the studied granite samples was in the range of 2.65 g/cm ³ to 2.72 g/cm ³ and the median particle diameter was between ~12 μm and 41 μm. According to the structural examination results obtained from the study, the chemical compositions of the extracted granite samples varied by area. While SiO 2 was the dominating component in certain locations, it was replaced by Fe 2 O 3 in another. This condition also had a direct effect on the densities of the granite samples extracted. At the conclusion of the study, it was found that the predominant factor affecting the radiation shielding characteristics of granites was the quantity of Fe 2 O 3 in the composition, with the greatest gamma-ray shielding qualities supplied by samples 4 and 5, which had the highest Fe 2 O 3 ratio. Our results indicate that sample 5 and the previously studied Capao Bonita sample had comparable half value layer values at low, medium, and high gamma ray levels. It may be concluded that Izmir granites are a more attractive option to granite for usage as radiation shielding building materials, owing to their high Fe 2 O 3 concentration, and may be a feasible alternative to less desirable concrete materials for shielding applications.
... In this section, the theoretical formulae used (Wood, 1982;El-Sayed Abdo, 2002;Erdem et al., 2010;Kurudirek et al., 2011;Yılmaz et al., 2011;Akkurt and El-Khayatt, 2013;El-Khayatt and Akkurt, 2013;Kassab et al., 2015;Abdel-Latif M et al., 2020) will be summarized. ...
By using an electro-slag re-melting procedure, new shielding steel alloys with varying chromium concentrations ranging from 2 to 18%, and a reduced nickel content of roughly 12% were developed. The mass attenuation μm, mean free path (MFP), effective atomic number Zeff, and electron density Neff, the energy buildup factor (EBF), and the energy absorption buildup factor (EABF) were calculated for the new developed steel alloys by using Phy-X/PSD software over the photon energy range (0,015–15 MeV). Furthermore, using the NGCAL online software, the macroscopic effective neutron removal cross-sections (ΣR) for 25.4 meV thermal neutrons, 4 MeV fast neutrons, and 10 MeV fast neutrons were determined. All cobalt-free steel prepared samples (S1, S2, S3, S4, and S5) were found to have lower mean free path (MFP) and half-value layer (HVL) values, as well as greater macroscopic effective neutrons removal cross section (ΣR) values, than their estimated equivalents for both carbon steel and stainless steel. Furthermore, based on the estimated values for the mean free path (MFP), the half-value layer (HVL), and the effective neutrons removal cross section (R), sample S5 with the greatest chromium content (17.68%) is shown to be a good candidate for gamma shielding rather than neutron shielding.
... To evaluate relevant parameters of radiation shielding of lead, the widely known software XCOM has been used [28][29][30]. Berger and Hubel [31] have developed software known as XCOM and a database that allows users to calculate attenuation coefficients for any element. XCOM is capable of generating radiation coefficients as well as cross-sections on a standard energy grid or a network grid for the procedures such as photoelectric absorption, incoherent and coherent scattering, and also pair production GAMMA RADIATION SHIELDING EFFICIENCY OF COMPOSITE MATERIAL Soylu et. ...
The paper analyzes the performance of various composite materials in the lead-free apron for radiation shielding in biomedical applications. The challenging task is to extend the duration of wearing an apron, reduce the weight, and increase the comfort level for physicians. The lead-free composite materials used an alternative to lead in an apron due to their excellent properties, such as mass attenuation coefficients, effectiveness against gamma radiation, flexibility and light weight, and absorption. The present study discusses different simulation software used to assess the properties of the shielding material against the radiation effects. At the end of the paper, the promising directions are presented for future research.
... To evaluate relevant parameters of radiation shielding of lead, the widely known software XCOM has been used [28][29][30]. Berger and Hubel [31] have developed software known as XCOM and a database that allows users to calculate attenuation coefficients for any element. XCOM is capable of generating radiation coefficients as well as cross-sections on a standard energy grid or a network grid for the procedures such as photoelectric absorption, incoherent and coherent scattering, and also pair production GAMMA RADIATION SHIELDING EFFICIENCY OF COMPOSITE MATERIAL Soylu et. ...
The paper analyzes the performance of various composite materials in the lead-free apron for radiation shielding in biomedical applications. The challenging task is to extend the duration of wearing an apron, reduce the weight, and increase the comfort level for physicians. The lead-free composite materials used an alternative to lead in an apron due to their excellent properties, such as mass attenuation coefficients, effectiveness against gamma radiation, flexibility and light weight, and absorption. The present study discusses different simulation software used to assess the properties of the shielding material against the radiation effects. At the end of the paper, the promising directions are presented for future research.
... Many glass types, including borates, tellurites, silicates, and so on, have been explored concerning experimental, theoretical, and simulation works [21][22][23]. However, few studies were published on the valorization of glass wastes [24], [25]. This is somehow inconceivable since the earth's crust has a limited quantity of primary raw materials and fossil fuels. ...
In the present work, by utilizing waste pharmaceutical glass (PG) within the attempt of gaining a value-added product for radiation shielding applications, a new glass system was fabricated with the nominal composition of x Bi2O3-(100-x)PG (x: 0, 5, 15, 25, and 35 wt%). Conventional melt quenching technique ensured to synthesize five different glass samples, namely Bi0, Bi5, Bi15, Bi25, and Bi35. For understanding the role of Bi2O3 in the PG system, we implemented several characterization analyses, including physical, structural, mechanical, and radiation shielding properties. According to the findings, the density of the glasses varied between 2.5344-3.4492 ±0.001 g.cm-3 for Bi0 to Bi35. On the other hand, the X-ray diffraction (XRD) technique confirmed the non-crystalline structure without any sharp peak existence. The mechanical parameter of the glases decreased with the increasing in Bi2O3 content in the glass composition. Radiation shielding competencies were determined experimentally with gamma transmission measurements with the energy range of 53-3.83 keV. The results were checked with generated outcomes with EpiXS program and MCNPX codes. The Bi35 sample with doped 35 wt% of Bi2O3 owns the lowest of HVL, MFP, EABF, and EBF values and highest MACs and Zeffs, which are desired for a shielding material, among the produced glasses. It is concluded from the outcomes obtained that the addition of Bi2O3 significantly increased the photon shielding ability of PG glasses.
... The traditional shielding materials has been focused on concrete and lead [5,6]. But they have some drawbacks, such as cracks and toxicity [7,8]. ...
In the present work, we investigate the structural, electronic and shielding properties of a series of BaSn1-xZnxO3 (x = 0.05, 0.10, 0.15, and 0.20) ceramic samples prepared using the conventional solid-state reaction. We use the Fourier transform infrared and X-ray diffraction (XRD) to delineate the structure, while the diffuse reflectance (R) spectra were used to determine the bandgap. The Rietveld refinement of the XRD patterns showed the emergence of a majority of cubic structures with the Pm-3m space group. The FTIR spectra for all-ceramic samples display three bonds around 613, 1066, and 1425 cm−1 that corresponded with the stretching vibration of Sn–O, δ(SnOH) vibration, and the existence of C–O vibration, respectively. The bandgap enhanced gradually from 3.14 to 3.18 eV with increasing ZnO. The radiation shielding properties of the prepared samples have been investigated experimentally then we benchmarked the results with the theoretical values, and the maximum relative difference (RD) is 6.290. Consequently, we theoretically explored the rest of the radiation shielding parameters, including linear attenuation coefficient, equivalent atomic number, mean free path, transmission factor, electron density, electron conductivity, and neutron removal cross-section. All the radiation-shielding properties showed a gradual reduction with the addition of ZnO to the ceramic system, while the neutron removal cross-section showed a gradual enhancement. Accordingly, it is deduced that the present samples can be used in the radiation-shielding field.
... Linear attenuation coefficients (LAC) of glass samples containing varying amounts of La 2 O 3 were measured for gamma energies of 356, 511, 662, 1173, 1275, and 1332 keV obtained from 133 Ba, 137 Cs, 22 Na, and 60 Co gamma-ray sources, respectively [40,41]. Measurements ...
In our work, we studied the impact of lanthanum oxide (La2O3) on barium-lead-borosilicate (BLBS) glass systems in terms of physical properties and photon shielding characteristics. With this motivation, we aimed at synthesizing a BLBS glass system with a composition of 6Na2O-0.8MgO-0.25Al2O3-(55-y)SiO2-11B2O3-7.3CaO-13BaO-0.83SrO-5.75PbO-yLa2O3, (y: 0, 5, 10, and 20 wt%), via traditional melting techniques. The fabricated glass samples, La-0 to La-20, were analyzed using some characterization techniques, including Archimedes' principle and spectroscopic gamma-rays experiment. According to the measurements, one can observe that all glass series show a transparent appearance irrespective of varying La2O3 content. On the other hand, the increasing La2O3 insertion ratio has a favorable influence on glass density (ρglass). That is, ρglass increases from 2.9419 to 3.3479 g.cm⁻³ in subjection to the amount of La2O3 from 0 to 20 wt%. Similarly, molar volumes (Vm) for the La-series are found to be in an inclining behavior, namely, from 23.52 to 25.46 cm³ mol⁻¹. With regards to the gamma-rays (356, 511, 661.7, 1173, 1275, and 1332 keV) attenuation characteristics, the linear attenuation coefficient (LAC) values obtained for the lowest energy by experimental and simulation methods for La-0 to La-20 samples were found in the range from 0.3298 to 0.4175 cm⁻¹ and 0.3349 to 0.3992 cm⁻¹, respectively. Similarly, the LAC for all energies increased as the La2O3 additive ratio increased; that is, the La-20 sample had the highest protection ability. In addition, we found out a good agreement among the FLUKA, XCOM, and experiments. Lastly, the LAC values of La2O3 added glass samples were compared with some concrete used for shielding, commercially available protection glasses, and some recent studies in the literature. The results showed that our glass samples, especially the La-20 glass sample, can be used as a potential candidate for photon shielding applications.
... The initial radiation dose and the average radiation dose result were used to calculate the linear attenuation coefficient and half-value layer using equation (2) and (3), as shown in Table 2. Linear attenuation coefficient was defined as the probability of absorbed or scattered photons per unit length of the absorptive materials [43]. The linear attenuation coefficient of the building materials had great importance for the determination of protection towards the damaging effects of photons on the human body [44]. The Table 2 showed the linear attenuation coefficient of Boyolali, Klaten, Magelang, Temanggung, and Semarang bricks respectively were 0.8896 cm -1 ; 0.7455 cm -1 ; 0.7115 cm -1 ; 0.7254 cm -1 ; and 0.7972 cm -1 . ...
The widespread use of radioactivity has culminated in adverse health consequences and has generated an entire health science study. It is established practice that certain precautions must be taken to avoid potential exposure to ionizing radiation like an x-ray. One way to control radiation hazards external is to use a radiation shield. In this study, clay-originated bricks were used as a shield and determine its linear attenuation coefficient of x-ray radiation. The bricks were collected from 5 regencies in Central Java province. Digital fluoroscopy was used as an x-ray radiation source and operated in 81 kV 32 mAs; also, it associated with the multipurpose detector. It shows that linear attenuation coefficient of Boyolali, Klaten, Magelang, Temanggung, and Semarang bricks respectively are 0.8896 cm-1 ; 0.7455 cm-1 ; 0.7115 cm-1 ; 0.7254 cm-1 ; and 0.7972 cm-1. Furthermore, we calculate the half-value layer of each brick and indicates that brick from Boyolali is the most effective as a shielding among others that can reduce half value of x-ray radiation dose. This research is expected to enhance the systems integration of radiation shielding safeties and allow for the effective treatment of radiation sources for both humans and the environment.
... Natural radiation varies widely between fields. However, when the radiation source is concentrated and confined to a particular area, human exposure to radiation from that source can be reduced through the use of carefully designed systems and procedures [1,2]. Recently, a lot of research has been done on the radiation protection properties of different materials using theoretical methods. ...
Radiation is a phenomenon that always exists in nature and we live together. With the development of technology, radiation has started to be used frequently in fields such as medicine, energy and industry, and therefore studies on radiation are increasing. Radiation protection methods have gained importance, especially since radiation is harmful to living things. These methods are distance, time and shielding. Shielding, the most important of these methods, is based on placing an obstacle between the system to be protected from radiation and the radiation source. For this reason, the researchers produced different materials for shielding radiation and examined the radiation absorption properties of these materials. Wood material is preferred because it is a renewable resource, the amount of energy used in the production of wooden building elements and structures
is low, and the amount of carbon dioxide produced in the production process is close to zero. It is seen that the wooden material, which we have seen in the past especially in housing construction, is widely used in the production of multi-storey buildings with new production technologies. Studies have been carried out on the radiation shielding properties of wood building materials, which are frequently used in building construction in recent years. In this study, radiation shielding properties of radial and tangential sawn timbers obtained from Red Pine tree (Pinus brutia Ten.) species were investigated. It was determined that the radiation shielding properties of radial and tangential sawn timbers gave similar results.
... The main parameters calculating the mass attenuation coefficients are the density and the chemical composition of the material (Erdem et al., 2010). Ag6 has the highest mass attenuation coefficient among the studied samples, due to its containment of silver that is a high atomic numbered element that is more effective for gamma-ray attenuation as the gamma-ray interactions with the matter like photoelectric effect, pair production and Compton Effect. ...
... For instance, concrete, tungsten, steel, and lead are the most successfully used for gamma-ray shielding. Lead-shields are frequently used in fields where space is limited (Harrison, 2008;Erdem, 2010). Nevertheless the largest deficit of lead is that it is poisonous (Lamarsh, 2001). ...
In the current study, it was shown that polystyrene (PS) composites holding tungsten (VI) oxide were formed in groups (10% to 50%) by radical polymerization. For this goal, the styrene reacted with BPO for 2.5 hours at 70 °C in tetrahydrofuran (THF) to give the consistent polymer. Synthesized PS were defined by FTIR, GPC (Mn = 7900 g/mol PDI = 1.66), SEM and 1H NMR spectroscopy. PS-tungsten (VI) oxide composites formed between 80-85°C. The gamma-ray of composites was calculated using the NaI(Tl) scintillation detector. Linear attenuation coefficients were also estimated hypothetically by the XCOM platform, taking into account the fundamental analysis of composites and comparing them with empirical outcomes. Among the composites studied, the best protective material was PS -50% W03 with lower absorption thicknesses and a higher linear slimming coefficient. Thermal degradation of unirradiated and irradiated polymer composites has also been examined
... To improve these disadvantages, hydrogen-rich polymers and epoxy with high-density polyethylene (HDPE) were developed. Also, these polymers were embedded with high-density elements, such as Fe, Pb, or W [7,8]. However, HDPE is limited by the amount of the material that boron and metal particles can constitute, as increasing this amount weakens the tensile strength and elasticity of HDPE [8][9][10][11][12][13][14][15]. ...
A numerical simulation for a radio frequency (RF) thermal plasma torch was carried out to identify the temperature and velocity distributions and determine the optimal design of a plasma system based on the coil turn and torch inner diameter parameters. Then, the optimized conditions of five coil turns and a torch inner diameter of 64 mm were applied to synthesize titanium boride nanoparticles. The major crystal structure of the synthesized titanium boride nanoparticles was TiB2, with TiB as a minor phase and an average particle size of 42 nm. Subsequently, the gamma-ray shielding performance was analyzed using synthesized titanium boride nanoparticles. Flexible shielding materials were fabricated using a hydrogel to load the synthesized nanoparticles. The attenuation coefficient of the titanium boride nanoparticle flexible material was 0.238 cm⁻¹, and the half-value layer was 2.91 cm.
Our research is about AN EPOXY-BASED COMPOSITE DESIGN AS AN ALTERNATIVE TO LEAD IN SHIELDING FROM Ionizing Radiation. Gamma and X-Ray radiations are used in industries, medical diagnostic centers, nuclear research
facilities, radioisotope research, and nuclear weapon development. Radiation shielding is essential for radiation-emitting equipment users to reduce or mitigate
radiation damage. Radiation shielding depletes radiation by inserting a shield of absorbing material between any
radioactive source. Lead is the most widely used shielding material because its ability to shield X-rays efficiently is
superior to that of other materials owing to its high Z number, high density, and low cost. But lead-based shielding materials often have a few significant downsides. Like high toxicity,
weight, poor flexibility, and poor chemical stability.
Considering that people spend most of their time in buildings (home, office, school, shopping mall, etc.), it is seen
that the radiation retention properties of building materials are important. Nuclear power plants are a complex of
structures that are of great importance in today’s energy-age world, but also bring some dangers. The most
important of these dangers is the possibility of radiation leakage from these structures in the event of an explosion.
In addition, shielding for radiation protection is important in medical applications and industry where
radiation is widely used. Therefore, the strength and durability properties of concretes to be used in the construction
of nuclear power plants need to be meticulously designed. All this shows how important and worthy of
research the subject of the study is. For this purpose, new materials that are easy to access, abundant and cheap,
and have high absorption capability are needed, rather than shield made only of lead materials. Perlite, pumice
and Ahlat stones are abundant in Bitlis (Turkey) province and are extracted from the quarries. The bims block
samples (B-1, B-2 and B-3) produced in factories in Bitlis. This study was carried out to investigate whether these
materials, which are used as building materials, have radiation absorbing properties in terms of their use in
different areas. Linear attenuation coefficients were calculated experimentally for gamma energies at 88.04 ±
0.01 keV, 356.50 keV, 661.60 keV, 834.80 ± 0.04 keV and 1173.20–1332.50 keV (for 109Cd, 133Ba, 137Cs, 54Mn
and 60Co radioactive point sources) using gamma spectrometry with a NaI scintillation detector. In addition,
photon absorption percentages, half value layer (HVL), tenth value layer (TVL) and mean free path (MFP) values
of the samples were calculated. The obtained data were evaluated by comparing with similar studies in this field
and the results obtained for lead shield. As a result of the study, it is seen that instead of using perlite and pumice
alone, it is better radiation trap when they are mixed with each other and formed into bims blocks.
Protection of personnel against ionising exposure is necessary to prevent occurrence of biological risks. The objective of this study is to arranged light and heavy nuclei at the surface state particle of composite geopolymer concrete when filler with metal (Ni or Fe) for X-ray shielding applications. The composite fly ash geopolymer concrete with fillers Ni and fly ash geopolymer concrete with Fe as a shield for X-ray radiation has been successfully synthesized by a simple method. The shielding composites were carried out using Fourier transform infra-red (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray mobile to determine optical properties, structural properties, surface morphology, and shielding performance. In this study shows strong linear correlation between structural properties and the effectiveness of X-ray shielding. The best composite as an X-ray radiation shield is composite concrete geopolymer with AC and Ni as a filler indicated by higher linear attenuation coefficient μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left(\mu \right)$$\end{document} due to present combination between heavy and light nuclei at the surface state of particle, consequently, produce high stability structural and optical properties, and bonding characteristics. The results in this study indicated composite concrete geopolymer fly ash with AC and Ni as a filler with sharp nodule at the surface state looks like prickly ball as a new composite for X-ray shield.
The porosity contents in metal matrix composite materials (MMCs) is one of the important factors that affect the
composite final properties. Thus, this topic had caught the focus of many researchers. However, several factors affect
the porosity content in this class of materials, including: reinforcement particle type, shape, and volume fraction. No
single article covers the effect of the aforementioned factors on porosity contents in MMCs. Hence, this article is
designed to summarize this effect to cover this gap in the literature.
Research into protection techniques from harmful effects of gamma radiation have increased contemporarily. The development of radiation-resistant materials having a high radiation resistance and absorption of different types of ionizing radiation could offer promising solutions to this matter. For this purpose, the preparation and examination of a novel type of polymer doped with various WO3 concentrations are presented in this study. To accomplish our main objective, we evaluated the effectiveness of their radiation shielding against gamma radiation from ¹³⁷Cs, ⁶⁰Co, and ²⁴¹Am. At all investigated energies, the measured and theoretical linear attenuation coefficient (LAC) values are highly similar, proving that the experimental LAC values can be used to reliably predict other radiation shielding characteristics. The half value layer (HVL) values decreased as the samples' WO3 level rises indicating that increasing the amount of WO3 in these samples increases their radiation shielding effectiveness. In addition, it was found a positive correlation between radiation energy and the mean free path (MFP) values. At 0.060 MeV, the MFP values are equal to 1.374 cm, 0.691 cm, 0.521 cm, and 0.369 cm at concentrations of 0, 10, 20, and 25% WO3, respectively reflecting that the MFP is reduced by 3.7 times due to the addition of 20% WO3 nanoparticles. From the transmission factor, it was found that improving the shielding ability of the proposed materials could be achieved by increasing and adjusting the thickness of the absorber depending on the required energy range used. It is noteworthy that the present studied samples (epoxy + waste marble + nano-WO3) that have exhibited a greater shielding ability than other nanoparticles added polymers like (Epoxy + nano-MgO30), and (silicone rubber + nano-WO330).
Extensive use of radioactive materials has led to the production of low-level nuclear waste that emits dangerous gamma rays which pollute the environment. Low-level nuclear waste is usually disposed in landfills to prevent damage from organisms exposed to gamma rays. These landfills are usually covered and capped with bentonite clay due to their desirable properties such as long-term chemical stability, low hydraulic permeability, easy access, and low price. This clay cover is responsible for controlling the emission of gamma rays and preventing hydraulic permeability. In this study, red mud powder additive as a waste product of steel industry with high specific gravity has been added to the bentonite clay in 0, 15, 30, and 45 percentages, to improve the performance of radiation protection and hydraulic conductivity prevention. For this, the effect of red mud and bentonite mixtures are investigated on the improvement of linear attenuation coefficient (μ) and hydraulic permeability coefficient (K) using experimental, theoretical, and simulation methods. Nal(Tl) detector with Cobalt60 source for the experimental procedure, XCOM database for theoretical approach, and MCNP code for simulation methods have been used, in two energy levels of 1173 keV and 1332 keV. Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) analyses are performed to identify fine particles and chemically analyze bentonite and red mud. The results show that bentonite with 45% red mud with a linear attenuation coefficient of 10.32 m-1 had the best performance at the two energy levels.
In this study, the thermal and radiation shielding properties of composites obtained using different ratios of tungsten(VI) oxide unsaturated polyester were investigated. Composites were prepared using WO3.2H2O powder in different ratios (10%, 20%, 30%, 40%, and 50%.), and based on Styrene unsaturated polyester were used as resins. The linear attenuation coefficients of the composites were measured by the NaI(Tl) gamma spectrometry system. The attenuation coefficients were also calculated theoretically by the XCOM platform, taking into consideration the basic analysis of composites, and compared with empirical outcomes. According to the results of XRD and particle size distribution of WO3.2H2O powder demonstrated had obvious diffraction peaks and its pore size distribution values were good. When the thermal degradation curves of the composites are examined, it is seen that the remaining ash amounts of the prepared composites and the % mass of the prepared composites overlap. It was clear that the best shielding material in the studied composites was styrene-based unsaturated polyester +50% WO3.2H2O with a higher linear attenuation coefficient.
https://shodhganga.inflibnet.ac.in/handle/10603/337842
A polydimethylsiloxane (PDMS) matrix soft elastic composite material with low-melting-point GaInSnPbBi high-entropy alloy (LHEA) inclusions was prepared to evaluate its radiation shielding performance. The LHEA was composed of two different three-component eutectic microstructures, which were grown in a mixed manner to form a complex eutectic structure. The inclusions had excellent mechanical properties that matched the deformation of the PDMS matrix. To evaluate the interaction of the shielding material with photons, the Monte Carlo N-Particle Extended and XCOM codes were used to determine the shielding parameters of the LHEA/PDMS composites, such as mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth value layer, mean free path and effective atomic number. The composite with 50-vol% LHEA had the best radiation shielding properties, validated by medical X-ray imaging experiments. The excellent shielding properties of the flexible lightweight composites were attributed to the higher mass attenuation coefficient of the LHEA inclusions than that of lead.
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The Kori-1 nuclear power plant has been permanently shut down since 2017, and its major structures, systems, and components are currently planned to be dismantled according to the final decommissioning plan. To protect dismantling workers from external radiation exposure dose during decommissioning, we propose a dose reduction method involving dual-layered Pb-free shielding. Based on the Monte Carlo method, the performance of the abovementioned method and various types of materials are optimized and estimated in terms of the equivalent dose rate and radiation shielding rate. The results showed that Pb-free shielding with dual layers exhibited better performance than the conventional shield. In addition, the Pb-free material of WC-Co showed a relatively high performance for the reduction of the external radiation exposure dose in the dismantling process of the steam generator (S/G). In the dismantling process of the S/G, the results of our simulation will offer the choice of materials and flexibility in the design of Pb-free shielding with dual layers.
Mass attenuation coefficients of the YBaCuO and BiPbSrCaCuO superconductors were determined at 511,661, and 1274 keV photon energies. The samples were irradiated using 0.5 mCi Cs-137 and 2 mCi Na-22 radioactive sources. The photons crossing the samples were counted using a multi-channel analyzer with a NaI(Tl) detector. The Nucleus II software was used to analyze the spectra. It was observed that the mass attenuation coefficient decreases with increasing energy and increases with increasing atomic number.
The design of future spacecraft such as the Crew Exploration Vehicle must take into account the radiation shielding properties of both the structural components as well as dedicated shielding materials. Since modest depths of shielding stop the vast majority of Solar Energetic Particles (SEP), the greater challenge is posed by the need to shield the crew from the Galactic Cosmic Rays (GCR), which include highly-charged and highly-energetic particles. Here, we report on results from tests performed with beams of 1 GeV/nuc Fe-56 at the Brookhaven National Laboratory. A wide variety of targets, both elemental and composite, was placed in the particle beams, and the spectra of particles emerging from the targets were measured using a stack of silicon detectors. Results are presented primarily in terms of dose reduction per g cm(-2) of target material, and support the conclusions of an earlier calculation by Wilson et al. showing that performance improves as the shield's mass number decreases, with hydrogen being by far the most effective shielding material. The data also show that, as depth increases, the incremental benefit of adding shielding decreases. (c) 2006 Published by Elsevier B.V.
The capabilities of some building materials used in Jordan to attenuate gamma radiation were tested. Measurements of the attenuation coefficients of limestone, bricks and concrete have been carried out using a HPGe-spectrometer. Narrow beam technique was used, with a multiple gamma radiation source of different energy lines. Results indicate that variations in the attenuation coefficient for all limestone samples, at the same energy line, are within the experimental uncertainties. On the basis of the results achieved, an empirical formula mu(m)=AE(-0.44) was proposed to calculate attenuation at various incident energies. Limestone of average thickness 7cm was found to stop 75% of a gamma beam of energy 662keV. Meanwhile a brick of effective thickness 7cm was found to stop 60% of the same beam. The total attenuation coefficient of concrete calculated at 1333keV was 11.2m(-1), which is less than that of limestone and bricks.
Accurate measurement have been made to determine radiation transmission of boron compounds by using an extremely narrow collimated beam transmission method for 59.54 and 80.99 keV gamma energy with a Si(Li) detector. Appreciable variations were observed in the transmission factors of the concrete samples including different boron wastes (borogypsum and colemanite concentrator waste). Additionally, mass attenuation coefficients were also calculated. It is seen that μ/ρ is increased with increasing boron concentration in the concrete and the both kind of boron waste have nearly the same property in the radiation transmission.
Mass attenuation coefficients μ/ϱ and mass energy-absorption coefficients μcn/ϱ are tabulated in units of m2 kg−1 for photon energies 1 keV to 20 MeV for 40 elements ranging from hydrogen (Z= 1) to uranium (Z= 92). In addition, μ/ϱ and μcn/ϱ values are tabulated over this same energy range for 45 mixtures and compounds of dosimetric interest, computed from the above data using fractions-by-weight of the constituent elements. Source data for these tables are primarily theoretical. The atomic photoeffect cross sections, with minor empirical modifications, are from the 1973 computations of Scofield. The incoherent (bound-electron Compton) and coherent scattering cross sections, also pair and triplet production cross sections, are from recently published (1975, 1979, 1980) compilations developed at NBS in collaboration with researchers from various laboratories including Kaman Sciences, Los Alamos Scientific Laboratory, Lawrence Livermore National Laboratory, Max-Planck-Institute (Mainz) and the University of Trondheim. Information is provided for estimating photonuclear contributions above 5 MeV. Differences for NSRDS-NBS 29 (1969) and Storm-Israel (1970) are of the order of 1% or less over most of the element-energy range, but in some cases are as much as 5%.
The photon linear attenuation coefficients (μ) have been calculated for four different igneous rocks which are widely used in industrial field using XCOM computer code and the results were compared with measured values. The relation between linear attenuation coefficients and some of the physical and mechanical properties of rocks has also been investigated by linear regression analysis. It has been found that with increasing linear attenuation coefficient, density, uniaxial compressive strength, bending strength, shore hardness and SiO2 percentage have also increased, however the other properties such as abrasion strength and porosity have decreased.
Monte Carlo simulations may be used to model radiation shielding for neutron diffractometers. The use of the MCNP computer program to assess shielding for a diffractometer is discussed. A comparison is made of shielding requirements for radiation generated by several materials commonly used in neutron optical elements and beam stops, including lithium-6 based absorbers where the Monte Carlo method can model the effects of fast neutrons generated by this material. Crown Copyright (c) 2006 Published by Elsevier B.V. All rights reserved.
Study has been made of the radiation shielding provided by recycled agricultural fibre and industrial plastic wastes produced as composite materials. Fast neutron and gamma-ray spectra behind composites of fibre–plastic (ρ=1.373 g cm−3) and fibre–plastic–lead (ρ=2.756 g cm−3) have been measured using a collimated reactor beam and neutron–gamma spectrometer with a stilbene scintillator. The pulse shape discriminating technique based on the zero-cross-over method was used to discriminate between neutron and gamma-ray pulses. Slow neutron fluxes have been measured using a collimated reactor beam and BF3 counter, leading to determination of the macroscopic cross-section (Σ). The removal cross-sections (ΣR) of fast neutrons have been determined from measured results and elemental composition of the composites. For gamma-rays, total linear attenuation coefficients (μ) and total mass attenuation coefficients (μ/ρ) have been determined from use of the XCOM code and measured results. Reasonable agreement was found between measured and calculated results.
During irradiation of lesions in cancer treatment with electrons, irregular field sizes are shaped by blocking off the areas to be protected usually with lead or Lepowitz metal of adequate thickness. Sometimes these blocks are placed directly on the skin. In such cases, the block should not only be of minimum weight (thickness), but also the residual dose received by the protected organs should be as small as possible. However, due to the production of bremsstrahlung, it is difficult to achieve a higher degree of attenuation unless a sufficient thickness of shielding material is used. Hence, a minimum or optimum thickness is needed to be measured. Transmission measurements are performed to determine suitable minimum thicknesses and to measure the transmission at this minimum thickness, for aluminum, copper, tin and lead for electron broad-beam field sizes 6×6, 10×10 and 20×20 cm2 of energies 6, 12 and 20 MeV produced by a medical linear accelerator. The ratio of the measured ionization with and without the shielding material in percent is expressed as a measure of transmission. The minimum thickness is `knee' position of the transmission curves, where the dose received by the organs (residual dose) is mostly dominated by the bremsstrahlung component and any addition of shielding material is not of much advantage in achieving further appreciable shielding effect. It is noticed that at this minimum thickness the percentage dose received by the vital organs behind the shield varies from 1 to 14% of the original unshielded dose as the atomic number of the shielding material increases from 13 (aluminum) to 82 (lead) and as the electron energy of the beam increases from 6 to 20 MeV. In other words, the effectiveness of shielding decreases from 99 to 86% as the atomic number increases from 13 to 82. Depending on the treatment volume, its position and the clearance between the electron cone and the skin, the dose received by the vital organs surrounding the tumor can be minimized by choosing the optimum thickness of these elements.
Mass attenuation coefficients of glasses in the system: xBi2O3(1−x)B2O3 (x=0.30, 0.35, 0.40, 0.45 and 0.55) were determined at 356, 662, 1173 and 1332 keV photon energies using a narrow beam transmission method. Appreciable variations were observed in these coefficients due to changes in the chemical composition of glasses. These coefficients were then used to determine effective atomic numbers of glass samples, which were found to be constant with bismuth concentration and energy.
A Windows version of XCOM, the well-known program for calculating X-ray and gamma-ray attenuation coefficients and interaction cross sections, has been developed. The new program, called WinXCom, has an improved user interface.
In recent years, there has been a need for compact shielding design such as self-shielding of a PET cyclotron or upgradation
of radiation machinery in existing facilities. In these cases, high performance shielding materials are needed. Concrete or
polyethylene have been used for a neutron shield. However, for compact shielding, they fall short in terms of performance
or durability. Therefore, a new type of neutron shielding material based on epoxy resin and colemanite has been developed.
Slab attenuation experiments up to 40 cm for the new shielding material were carried out using a 252Cf neutron source. Measurement was carried out using a REM-counter, and compared with calculation. The results show that the
shielding performance is better than concrete and polyethylene mixed with 10 wt% boron oxide. From the result, we confirmed
that the performance of the new material is suitable for practical use.
Since lead has recently been recognized as a source of environmental pollution, we have investigated new electron shielding materials that do not contain lead. We compared the shielding thicknesses of a hard plate and a sheet composed of the new materials with that of lead for electron beams. The shielding thickness was evaluated as the thickness required for shielding primary electrons. The comparison revealed the shielding ability of the hard plate and sheet is approximately equivalent to 1.0 and 0.9 times that of lead, respectively. The thickness (in millimeters) required for shielding by the hard-plate, as well as the thickness of lead, is related to approximately half of the electron-beam energy (in MeV). The shielding ability of the sheet is also equivalent to that of Lipowitz alloy. Moreover these materials are environmentally friendly, and can be easily customized into arbitrary shapes. Therefore they can be used as lead substitutes for shielding against electron beams.
The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.
Computational Methods in Reactor Shielding
- J Wood
Wood, J., 1982. Computational Methods in Reactor Shielding. Pergamon Press, New
York, USA.