Narrow Beam Transmission Geometry Research Articles

The effect of rare earths (Nd3+, Er3+, Yb3+) additives on the radiation shielding properties of the tungsten oxide modified tellurite glasses

Abstract In this study, we have reported on the effect of the rare earth oxides on the radiation protection performance of the tellurite glasses. In order to determine the effect of rare earth oxides on the radiation shielding properties of tungsten oxide (WO3) modified tellurite glasses, three rare earth element oxides (Nd2O3, Yb2O3, and Er2O3) have been selected. The glass systems have been synthesized using the traditional melt quenching method and were doped with the different amount (1 %, 3 %, 5 %) of the oxides of rare earth elements (Nd2O3, Yb2O3, Er2O3). The linear attenuation coefficient, mass attenuation coefficient, half value layer, and effective atomic number of the synthesized samples were experimentally measured for 662, 1,173 and 1,332 keV gamma-ray energies which were emitted from 137Cs and 60Co radioactive sources. Measurements were conducted in narrow beam transmission geometry using a NaI(Tl) scintillation detector. In addition, all these parameters were calculated theoretically using the WinXCOM program in the energy region of 0.015–15 MeV. The addition of different types and amounts of rare earth oxides to the tellurite glass system was found to significantly enhance the radiation protection performance of the glasses. In particular, it was found that the radiation shielding characteristics of the glasses improved with increasing amount of rare earth doping, the TWYb5 glass system had the best radiation shielding properties, and there was a trend among the doped rare earth oxides in the form of Yb > Er > Nd according to their radiation shielding performance.

An experimental and theoretical study to evaluate Al2O3–PbO–B2O3–SiO2–BaO radiation shielding properties

This study's objective is to evaluate an Al2O3–PbO–B2O3–SiO2–BaO glass system's radiation shielding characteristics. The composition of the glasses is 15Al2O3–25PbO–(60-x)B2O3–10SiO2–xBaO, with x in the 5–20 mol% range. Experimental results were used to determine the samples' linear attenuation coefficients (LAC), which were then confirmed by Phy-X program. Utilizing narrow beam transmission geometry, the experimental LAC values were determined. According to the results there was high agreement when comparing the theoretical and experimental values. The LAC values were used to calculate the prepared glasses' mass attenuation coefficients (MAC) and other relevant properties. The mean free path (MFP) values of the sample with 5 mol% BaO were 0.079, 2.549, 3.944 and 4.273 cm at 0.0595, 0.662, 1.173, and 1.332 MeV, thus demonstrating that raising the glass system's BaO enhances the prepared glasses' shielding capacity. According to radiation protection efficiency (RPE), the glasses' capacity to shield the photon is enhanced when their BaO content rises.

Investigation of natural radionuclides and radiation shielding potential of some commonly used building materials in Northwestern Nigeria

This study assessed the gamma-ray shielding potential of clay, sand, gypsum and kaolin commonly used as a building material in Northwestern, Nigeria. The radiological status of the samples was first evaluated by determining the activity concentrations of 238U, 232Th and 40K using NaI (Tl) detector after which elemental composition and mass density were determined using Neutron Activation Analytical Technique. After which the mass attenuation coefficients (MAC), linear attenuation coefficients (LAC), half value layer (HVL), tenth value layer (TVL), and effective atomic number (Zeff) were determined experimentally and theoretically using standard point sources of 137Cs and 60Co photon peaks (0.662 and 1.332, 1.173) MeV and Py-MLBUF software. The activity concentrations were found to range from 51 to 59 Bq kg−1 with a mean value of 59 Bq kg−1 for 238U, 24 to 27 Bq kg−1 with a mean value of 29 Bq kg−1 for 232Th, and 219 to 247 Bq kg−1 with a mean value of 247 Bq kg−1 for 40K which were about within the world recommended values of 33, 45 and 420 Bq kg−1 respectively. The results of the elemental compositions show that Si, Al, K, Fe, and Ba in clay and sand samples have concentrations in the range of 36.83–78.48%, 1.92–26.05%, 6.33–21.96%, 2.39–19.09%, and 0.09–1.44%, respectively, while in kaolin and gypsum, results revealed that Si, Al, K, Fe, and Ca range between 0.34 and 65.52%, 1.14–35.82%, 0.00–12.12%, 0.00–5.77%, and 0.00–96.6%, respectively. However, the concentrations of other elements such as Mg, Ti, Mn, Zn, Na, and Ba varied significantly with the samples. The results showed that clay has an average density of 1.96 g/cm3, sand has 2.32 g/cm3, kaolin has 2.63 g/cm3, and gypsum has the highest density with a value of 2.66 g/cm3 compared to other samples. During the measurements, a thallium-activated sodium-iodide NaI (TI) detector was used. A narrow beam transmission geometry condition was adopted for the measurements to ensure minimal scattered radiation. Absorption and attenuation of gamma beams as a function of sample thickness against gamma energy generally exhibit an increasing gamma ray behaviour as the sample thickness increases from 1 to 3 cm. The results showed that the gypsum, kaolin, sand, and clay were capable of attenuating 63.5%, 61.5%, 58.4%, and 44.2 of gamma-ray photons of energy 0.662 MeV at 3 cm thickness %, respectively, and 40.6%, 32.9%, 30.6%, and 27.3% of gamma energy 1.332 MeV at 3 cm thickness, respectively. The results showed that MAC, LAC, and Zeff of all the samples decreased with an increase in photon energy, while those of HVL and TVL increased. The experimental results for all the gamma-ray shielding parameters were found to be in good agreement with the theoretical values obtained using Py-MLBUF. The results have shown that all the samples have similar photon attenuation behaviours; however, gypsum has the best shielding potential than kaolin and this is attributed due to its highest density value.

A novel vanadium pentoxide doped glasses characterization for radiation shielding applications

Glasses are actively used in various fields, from industry to health. Especially, special doped glasses used in radiation areas may vary depending on the type and energy of the radiation. Glasses made of high-density and effective radiation-absorbing materials generally provide adequate protection against X and gamma rays. As an example, in this study, a 42.5P2O5–42.5B2O3–(15−x)Li2O–xV2O5 (x = 0, 2.5, 5, 10 and 15) glass system was produced using the melt quenching technique. The obtained X-ray patterns indicated that lack of crystalline peaks, verifying the glassy nature of all synthesized glass series. The glass transition temperatures and the glass thermal stability were determined using a Differential Thermal Analysis (TGA). The glass transition temperature and thermal stability was found to deteriorate with increasing V2O5 content. The radiation absorption properties of these glass system produced were investigated with 384 keV, 1173 keV and 1333 keV energized gamma using narrow beam transmission geometry. The NaI(Tl) detector system have been used to obtain γ-ray spectra. According to the obtained mass attenuation coefficients (μm) results, it has been determined that as the V2O5 ratio in the glass increases, it provides more effective results in radiation shielding. When the experimental results are compared with the theoretical XCOM results, there are a good match between the values. Finally, the radiation shielding properties of this produced glass system are compared with previously studied standard glasses to refer to the superiority of the installed systems.

Synthesis of transparent binary germanate glasses and determination of their shielding performance against the gamma radiation

ABSTRACT In this study, we synthesized binary germanate glasses with compositions of GeO2 – Bi2O3, GeO2 – PbF2, and GeO2 – V2O5. The traditional melt-quenching method was used for glass synthesis. The radiation shielding properties of the synthesized samples were calculated theoretically and measured experimentally as well. A narrow-beam transmission geometry, which uses a NaI(Tl) detector, was employed to measure linear attenuation coefficient, mass attenuation coefficient, half-value layer, and effective atomic number values of the glasses at gamma-ray energies of 662, 1173, and 1332 keV and, 137Cs, and 60Co radioactive point sources were used to produce gamma-ray photons of these energies. Additionally, all the above parameters were also calculated theoretically using the WinXCOM software in the 0.015-15 MeV energy range to confirm the accuracy of the measurements. A good agreement between theoretical and experimental findings was observed. It was also found that the increase in the concentrations of Bi2O3, PbF2, and V2O5 network modifiers improved the radiation shielding capacity of synthesized germanate glasses. The results revealed that the GeBi30 glass has superior shielding properties among the synthesized germanate glasses.

Precipitation-hardening stainless steels: Potential use radiation shielding materials

In this study, it was focused on the research of new materials with high attenuation efficiency that can be used as radiation shielding material due to the incapability of conventional materials. In accordance with this purpose, the radiation shielding capabilities of four different precipitation-hardening stainless steels (PH-SSs), which are symbolized 15-5PH, 15-7PH, 17-4PH and 17-7PH, were determined both experimentally and theoretically in a wide range of radiation energy. For experimental measurements, two different detectors (Si(Li) and Na(Tl)) and twenty-three different photon energies (from 22.1 to 1332.5 keV) emitted from seven different radionuclides were used in narrow-beam transmission geometry. Phy-X/PSD software were used for theoretical calculations. The theoretically calculated parameters were determined both in the photon energies emitted by the radionuclides used in the experiment and in the continuous energy range of 0.015–15 MeV. Furthermore, in order to make a remarkable assessment of the integration of PH-SSs to nuclear energy applications, the all results obtained have been compared with the corresponding values of Fe-based steel concretes (steel-scrap (SS) and steel-magnetite (SM)), which are widely used as conventional shield materials in nuclear power plants. Moreover, in order to choose the best material to be used in nuclear applications among the PH-SSs, the results were evaluated comparatively in terms of both the characteristics of the materials and the magnitude of the radiation shielding parameters. Consequently, it was concluded that the material with the best radiation shielding performance among the examined PH-SSs was 15-7PH and the radiation shielding performance ranking was generally in the form of 15-7PH ≥ 15-5PH > 17-4PH > 17-7PH > SM > SS. Due to both high attenuation efficiency and superior properties for radiation shielding, it was determined that the PH-SSs can be used as new shielding materials in nuclear applications.

Physical, structural and nuclear radiation shielding behaviour of xBaO-(0.30-x)MgO-0.10Na2O-0.10Al2O3-0.50B2O3 glass matrix

In the present investigations, six cylindrical shaped glass sample having chemical composition x BaO-(0.30-x) MgO-0.10Na2O-0.10Al2O3-0.50B2O3 (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30 mol fraction) were prepared by melt quenching technique. The density, molar volume, oxygen packing density (OPD), oxygen molar volume (OMV), Poisson's ratio, barium inter ionic distance, Polaron radius and field strength were calculated for the prepared glass samples. The values of linear attenuation coefficients (LAC) were measured experimentally by using narrow beam transmission geometry in the gamma photon energy range of 59.54–1332 keV. In order to ascertain the application of the prepared glasses in the field of radiation protection and design, the values of LAC were used to calculate various gamma ray interaction parameters namely half value layer (HVL), Radiation Protection Efficiency (RPE), Mass Attenuation Coefficient (MAC), effective atomic number (Zeff), electron density (Ne) and Exposure Buildup Factors (EBFs). The values of fast neutron removal cross sections (∑R cm−1) were also calculated for the prepared glass matrix. The theoretical values of attenuation parameters were determined using online software Phy-X/PSD and FLUKA (Monte-Carlo) simulation code. Excellent agreements have been observed between experimental, theoretical and simulation results for the prepared glass samples. Furthermore, the radiation shielding properties for the prepared glass samples were compared with conventional used concretes and commercial radiation shielding glass (RS253 G-18). On the basis of the obtained results, it has been reported that the prepared glass samples possess satisfactory physical reliability and superior shielding efficiency against gamma rays and fast neutrons as compared to conventional/commercial shielding materials.

Gamma radiation shielding properties of recycled polyvinyl chloride composites reinforced with micro/nano-structured PbO and CuO particles

In this work, the γ-ray shielding characteristics of fabricated recycled polyvinyl chloride (rPVC) loaded with micro and nano fillers of PbO and CuO composites were investigated. The PbO/rPVC and CuO/rPVC composites were prepared by changing the percentage of injected materials (PbO and CuO) between 10% and 40% with additions by 10%. Gamma-ray attenuation properties, such as mass attenuation coefficients, linear attenuation coefficients and half-value layer for PbO and CuO-supported polymers were obtained in the energy range between 59.5 and 1408.0 keV using narrow beam transmission geometry. These experiments were carried out by using a HPGe detector and five standard radioactive sources [241Am, 133Ba, 137Cs, 60Co and 152Eu]. Moreover, equivalent atomic numbers and the exposure buildup factor (EBF) values for incident photon energy in the range from 0.015 MeV to 15 MeV were also calculated by Geometric Progression (G-P) method. The experimental results revealed that, the measured values of the linear attenuation coefficients of the PbO/rPVC and CuO/rPVC composites showed their dependence on the type and the concentration of the filler (either PbO or CuO) and also on the incident gamma ray energy. Increasing the filler weight fractions wt.% in the rPVC matrix, increases the linear attenuation coefficients of the composite and the improvement is more significant in case of PbO compared to CuO of the same filler wt.% at the same energy. The results also demonstrated an enhancement in the radiation protection behavior of rPVC composites due to the addition of PbO and CuO fillers as nano-sized particles.

Investigations on physical, structural and nuclear radiation shielding behaviour of niobium–bismuth–cadmium–zinc borate glass system

In the present paper, glass sample with the chemical composition xNb2O5+0.20Bi2O3+0.20CdO+0.10ZnO+ (0.50-x)B2O3 (where x = 0.05, 0.10, 0.15, 0.20, 0.25 mol fraction) were prepared by melt quenching-annealing technique. The density, molar volume, oxygen molar volume (OMV) of the glass samples are found to increase increases from 5.35 to 5.65 gcm−3, 32.69–37.32 cm3/mole, 14.323–14336 cm3/mole, respectively, with the increase in molar concentration of Niobium pentoxide. The value of Poisson's ratio shows a very small variation in the range of 0.240–0.247 for the present glass matrix, however these results confirms that the prepared glass samples have high cross link density. The linear attenuation coefficients were measured experimentally by employing narrow beam transmission geometry (total scatter acceptance angle = 2.22°) with NaI(Tl) spectroscopy in the gamma photon energy range of 59.54–1332 keV. These values of linear attenuation coefficient were then further used to calculate other attenuation parameters namely Half Value Layer (HVL), Radiation Protection Efficiency (RPE), Mass Attenuation Coefficient (MAC), effective atomic number (Zeff), electron density (Ne) and Buildup Factor (BF). Measured values of attenuation parameters have also been compared the values obtained theoretically using online software Phy-X/PSD and Py-MLBUF as well as with values obtained through FLUKA (Monte-Carlo) simulations code. Excellent agreements have been observed between experimental, theoretical and simulation results for the prepared glass samples. In addition to this, fast neutron removal cross sections (∑R cm−1) were calculated for the glass matrix under investigations. On the basis of the obtained results, it has been reported that the prepared glass samples possess superior shielding efficiency against gamma rays and fast neutrons as compared to conventional shielding materials.

Experimental and theoretical analysis of radiation shielding properties of strontium-borate-tellurite glasses

The aim of this investigation is to analyse the radiation shielding features of a SrO–B2O3–TeO2 glass system. The glasses have the composition of 10SrO-(90-X)B2O3-XTeO2, where X is equal to 40, 45, 50, 55, and 60 mol%. The mass attenuation coefficients (MAC) of the samples were experimentally determined and were validated with results obtained using the Phy-X/PSD software. Narrow beam transmission geometry was utilized to obtain the experimental MAC values. When comparing the experimental and theoretical values, the results were found to strongly agree with each other. Using the MAC values, the linear attenuation coefficients (LAC) of the glasses were determined. The results demonstrated that the LAC values decrease with increasing energy, meaning that the glasses are more effective against lower energy photons. The radiation protection efficiency (RPE) showed that increasing the TeO2 content in the glasses improves the shielding ability of the glasses. The HVL and MFP were next calculated and the SBT60 sample showed to have the lowest values at all energies, while having the greatest Zeff and Neff. Lastly, the MFP results for the SBT60 glass were compared against other common radiation shields and it was demonstrated that the sample outperformed most of the shields it was compared against. Therefore, it was concluded that the SBT60 glass has great potential as an environmentally friendly shield for radiation applications.

Gamma Radiation Shielding Properties of Some Binary Tellurite Glasses

The radiation shielding properties of some binary tellurite glasses have been investigated both theoretically and experimentally. A series of tellurite glasses modified with different types and amounts of modifiers (Nb2O5, B2O3, ZnO, GeO2, WO3, MoO3, and V2O5) have been synthesized using the traditional melting and quenching method. In order to confirm the vitreous nature of the as-synthesized samples, XRD measurements were performed. As for the gamma radiation shielding purposes, linear attenuation coefficient, mass attenuation coefficient, half-value layer and effective atomic number values of the samples were experimentally measured for 662, 1173, and 1332 keV gamma-ray energies emitted from 137Cs, and 60Co radioactive sources. Measurements were performed at narrow-beam transmission geometry by employing a NaI(Tl) scintillation detector. In addition, all these parameters were theoretically calculated using the WinXCOM program in the energy region of 0.015 to 15 MeV. A good agreement was observed between theoretical and experimental values. In order to estimate the gamma-ray shielding effectiveness of the glass samples, all investigated protection parameters were compared with those of commercial RS 253 G-18 glass and some shielding concretes that are commonly used in the nuclear application. It was seen that our synthesized tellurite-based glasses have better shielding properties than standard shielding materials. The results revealed that TeW-3 glass containing 80 mole% TeO2 and 20 mole% WO3 is the most effective shield among the synthesized glasses.

Evaluation of the physical, structural, thermal, and advanced radiation absorption characteristics of SiO2–Na2O–K2O–P2O5–CaO bioactive glasses

We report herein an evaluation of the physical, structural, thermal, advanced photon energy absorption, and fast neutron removal characteristics of a series of bioactive glasses having the compositions 20SiO2-7.5Na2O-7.5K2O-(65–x)P2O5-xCaO, where x = 2.5, 5.0, 7.5, and 10.0 mol.%. X-ray diffraction (XRD) patterns confirmed the amorphous nature of these phosphosilicate glass systems fabricated by the melt-quench technique. To confirm the in vitro bioactivity of the prepared glasses, powdered samples of each composition were compressed into pellets and then soaked in simulated body fluid (SBF) at 37 ± 0.5 °C for 28 days. Soaked samples were investigated by means of XRD, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS/EDX). Thermo-gravimetric and differential thermal analysis (TG-DTA) was applied to determine the glass transition temperature (Tg) and crystallization temperature (Tc) for each glass sample. Fourier-transform infrared (FTIR) measurements were performed in the range 4000–400 cm−1, and showed the bending and stretching motions of different groups and the presence of CO2 and OH− groups in the glasses. Radiation absorption properties, such as mass energy absorption coefficient (μen/ρ), kinetic energy released per unit mass (KERMA) relative to air (ҠR), and mean free path values have been obtained for the bioactive glasses and compared with those of registered 45S5 Bioglass®. The simultaneous variation of mass energy absorption and mass attenuation values with photon energy has been explored to visualize the difference between absorption and attenuation. Linear attenuation coefficients for the present glass samples have been measured at photon energies of 511, 662, 1173, and 1332 keV in narrow-beam transmission geometry, and were in good agreement with theoretical results (error < 2 %). Further, detailed comparative analysis of energy absorption build-up factor (EABF) values for the glass samples has been conducted using two software tools, namely Photon Shielding and Dosimetry (PSD) and EXABCal, as well as on the basis of equivalent atomic number (Zeq) and effective atomic number (Zeff). We also attempted to calculate effective removal cross-sections (∑R) in order to evaluate the neutron absorption performances of these glass samples. The present detailed analysis shows that glass sample S4 with 10 mol.% CaO exhibits the most promising radiation absorption properties, resembling those of 45S5 Bioglass®.

On the use of green concrete composite as a nuclear radiation shielding material

In the present study, the samples of sustainable green concrete composites reinforced with hematite were prepared by partially replacing Ordinary Portland Cement (OPC) with flyash. The mechanical and gamma radiation shielding parameters have been measured experimentally for these prepared concrete composites. The experimental measurements were performed by using narrow beam transmission geometry (total scatter acceptance angle (θsc) = 1.78°) with NaI(Tl) spectroscopy in the gamma photon energy range of 59.54 keV–1332 keV. These experimentally measured values of linear attenuation coefficient are further used to calculate the values of half value layer, mass attenuation coefficient, effective atomic number, electron density, exposure build up factor, Klein-Nishina electronic, electron transfer and Compton mass attenuation coefficients. The fast neutron removal cross sections (∑R cm−1) were calculated for the concrete samples under investigations. The experimental values of mass attenuation coefficient have been compared with the results of theoretical values obtained by using winXCOM computer software and FLUKA simulations code. Excellent agreements have been observed between experimental, theoretical and simulation results.

GAMMA RADIATION SHIELDING PROPERTIES OF NATURAL GLASS OBSIDIAN

The present study was carried out to estimate gamma radiation shielding properties of natural glass obsidian. For this purpose, linear attenuation coefficient, mass attenuation coefficient, mean free path, half-value layer, tenth-value layer, effective atomic number and effective electron number values of obsidian samples in black and brown colors were experimentally measured for 661.66, 1172.23 and 1332.48 keV gamma ray energies obtained from 137Cs, and 60Co radioactive sources. Measurements were performed at narrow-beam transmission geometry using a NaI(Tl) scintillation detector. In addition, all these parameters were theoretically calculated by using WinXCOM program in the energy region of 0.015 to 15 MeV. A good agreement was observed between theoretical and experimental values. Furthermore, energy absorption and exposure buildup factors (EABF and EBF) of obsidian specimens were determined in the energy range of 0.015 to 15 MeV using G-P fitting method. Finally, it can be concluded that these naturally occurring volcanic glasses can be used for radiation shielding applications.

Synthesis and photon interaction characterizations of some bioactive glasses

We aim to explore the photon interaction characteristics for some bioactive glass having composition 20SiO2-7.5K2O-7.5Na2O-xCaO-(65-x) P2O5 where x= 2.5, 5.0, 7.5, 10.0 mol %. These bioactive glasses are fabricated via melt quenching technique and labelled as GC1, GC2, GC3, GC4 respectively. XRD results revel the amorphous nature of glass samples. Physical Parameters such as density and optimum thickness range were measured for these glass samples. Density increases with the increase in CaO content while optimum thickness range decreases with the increase in CaO content for prepared glass samples. The mass attenuation coefficient (µm)theo is computed using WinXCom software package while experimental mass attenuation coefficient (µm)exp is evaluated using narrow beam transmission geometry at 511, 662, 1173 and 1332 keV. The values of mass attenuation coefficient, both experimental (µm)exp and theoretical (µm)theo are in good agreement with each other. Similarly, the experimentally obtained other photon interaction parameters such as effective atomic number (Zeff), electron density (Ne) and thickness normalising parameters (mean free path (mfp), half value layer (HVL), tenth value layer (TVL)) values are comparable with theoretical ones. Although, radiation protection efficiency (RPE) of GC4 glass sample is maximum for all specified photon energies. While comparing GC4 glass sample with commercially used 45S5 bioglass; it has been observed that all parameters are nearly same. Hence, GC4 glass sample having comparable bioactivity can easily replace 45S5.

A research on the gamma ray attenuation characteristics for real bone and manganese substituted artificial bone dust

This research focalized on the gamma ray attenuation charesteristics of real bone and manganese substituted Nano hydroxyapatite artificial bone dusts. The current samples were excited with using 59.5 keV photons emitted from an 241Am annular radioisotope source with 50 mCi activity by using a narrow beam transmission geometry and detected with using Ultra Low Energy Germanium detector with a resolution 150 eV at 5,95 keV experimentally. The gamma-ray attenuation parameters such as linear attenuation coefficient, half value layer, tenth value layer and mean free path are also calculated experimentally and theoretically. The present results points out that the attenuation values of the manganese substituted hydroxyapatite artificial bone dust is very close to the value of the real bone.

A comprehensive study on radiation shielding characteristics of Tin-Silver, Manganin-R, Hastelloy-B, Hastelloy-X and Dilver-P alloys

In this study, it is aimed to investigate alloys that can replace lead and its derivatives in terms of radiation shielding. A new alternative shielding material must have optimum properties that should be present in a protective material. For this purpose, this study focused on the determination of the radiation-shielding characteristics of five different alloys named Tin-Silver, Manganin-R, Hastelloy-B, Hastelloy-X and Dilver-P. The photon interaction parameters (µ, µm, λ, X1/2, σT, σe, Zeff, Neff, σeff and RPE) that give significant information about the radiation shielding capacities of the materials were calculated for the alloys in the energy range from 30 to 1333 keV. The narrow-beam transmission geometry was used to determine these parameters accurately and was adjusted such that the error rate is minimized. The present samples were irradiated with photons of nineteen different photon energies emitted from seven different radionuclides (241Am, 133Ba, 109Cd, 152Eu, 22Na, 137Cs and 60Co). Photon intensities were measured by using two different detectors (Si(Li) and NaI(Tl)) for convenient photon energy regions. Then, these parameters were also calculated theoretically using Phy-X/PSD software in order to compare the experimental and theoretical results. Furthermore, the Rinc/total, Zeq, G-P fitting coefficients (a, b, c, d and XK) and exposure build-up factors (β) for the alloys were calculated using Phy-X/PSD software at photon energy range from 0.015 to 15 MeV. In order to make a significant comparison about the shielding capacities of investigated alloys, the µm values obtained for the alloys were compared with corresponding values of Pb metal, RS 253 glass and Cupero-Nickel alloy. Consequently, the descending order of MAC values in the all surveyed energy region was obtained as Tin-Silver > Manganin-R > Hastelloy-B > Hastelloy-X > Dilver-P. In the low energy region, it was found that the all present alloys have better shielding performances than RS 253 glass and Cupero-Nickel alloy. The experimental results also revealed that the Tin-Silver alloy has 25% better shielding performance than Pb metal in the energy range of 30–88 keV. Finally, it was concluded that Manganin-R alloy could be considered as the most ideal shielding material in the entire photon energies studied along with its other superior features (high density (10.22 g cm−3), high melting point (2500–2600 °C), high tensile strength (560–1150 MPa), high modulus of elasticity (320 GPa) and high specific heat (305 J K−1 kg−1) although the Tin-Silver alloy had the highest µm values among the examined alloys.

Investigation of some nuclear engineering materials in terms of gamma ray buildup factors at experimental energies used in nuclear physics experiments

ABSTRACT In shielding studies, the gamma ray buildup factor is referred to an attenuation correction when the narrow beam transmission geometry conditions are not met. This is the case if there is a beam divergence and a considerably thick material is used as shield. In the present work, a linear logarithmic interpolation based on five parameter geometric progression (G-P) fitting method was used to calculate energy absorption (EABF) and exposure buildup factors (EBF) at discrete energies for some standard nuclear engineering materials (SNEM) such as concrete, Pb glass, brass, bronze and stainless steel, and for some recently developed shielding alloys and glasses. Calculations were made at different penetration depths (1–20 mfp) using photons emitted from the standard radioactive sources such as 133Ba (0.356 MeV), 137Cs (0.662 MeV), 60Co (1.173, 1.332 MeV) and 22Na (0.511, 1.275 MeV). Results have been compared with MCNP6.1 Monte Carlo simulation code wherever possible and a reasonable agreement (Relative difference around 10% up to 10 mfp except for Pb glass) has been achieved. Results also showed that the gamma ray buildup correction is necessarily required since buildup factors are greater than unity even at lowest penetration depth, i.e. 1 mfp. The reported data on EABF and EBF for the energy values of radioactive sources may be of practical use in shielding calculations and estimations.

Gamma-ray attenuation parameters for polymer composites reinforced with BaTiO3 and CaWO4 compounds

Various composite shielding materials have favorable structural, mechanical, physical, and nuclear properties, besides their economic affordability. Such properties have widened the usage of composites around the globe in large-scale installations such as nuclear medical facilities, nuclear power plants, and spent nuclear fuel storage. In the current study, two groups of polymer composites have been prepared and their gamma-ray attenuation characteristics have been investigated both experimentally and theoretically. Four samples of each group have been prepared by varying the doped material (BaTiO3 and CaWO4) percentage between 5% and 20% with increments of 5%. To investigate the gamma-ray attenuation features, the linear attenuation coefficient, radiation protection efficiency, half value layer, mean free path, and effective atomic number parameters for these polymer composites reinforced with BaTiO3 and CaWO4 were obtained in the energy range between 59.5 and 1408.0 keV (at 22 different energies) using narrow beam transmission geometry. The experiments were performed with the aid of an HPGe detector and eight different radioisotope point sources. According to the experimental and theoretical results, BaTiO3 (20%) and CaWO4 (20%) have better gamma-ray attenuation properties than the other prepared polymer composites. Moreover, CaWO4 (20%) has better gamma-ray attenuation features than BaTiO3 (20%).

A Comprehensive Research on Gamma-Ray Attenuation Characteristics of the Metal-Doped Hap and Natural Animal Bone

This investigation focuses on the gamma ray attenuation parameters of natural animal bone, iron, cobalt, copper and zinc doped Nano hydroxyapatite artificial bone powders and pure hydroxyapatite. The present specimens were excited by means of gamma ray photons with 59.5 keV energy radiated from a 241-Amercium annular radioactive source with 50 mCi activity by means of narrow beam transmission geometry. The transmitted gamma-rays were counted with using Ultra Low Energy Germanium (Ultra-LEGe) detector with a resolution 150 eV at 5.95 keV . The gamma-ray attenuation characteristics such as mass attenuation coefficient (MAC) ( µ/ρ ), linear attenuation coefficient (LAC) ( µ) , half value layer (HVL), tenth value layer (TVL) and mean free path (MFP), which has a significant role in the attenuation studies, are also calculated. The values obtained were checked with the predicted values from the XCOM NIST. The results show that the attenuation data of the metal-doped hydroxyapatite synthetic bone dust is very close to the value of the natural animal bone.