This study aims to explore the radiation protection properties of white mortars based on white ce... more This study aims to explore the radiation protection properties of white mortars based on white cement as a binder and Bi2O3 micro and nanoparticles in proportions of 15 and 30% by weight as replacement sand. The average particle size of micro- and nano-Bi2O3 was measured using a transmission electron microscope (TEM). The cross-sectional morphology and distribution of Bi2O3 within the samples can be obtained by scanning electron microscopy (SEM), showing that nanoscale Bi2O3 particles have a more homogeneous distribution within the samples than microscale Bi2O3 particles. The shielding parameters of the proposed mortars were measured using the HPGe detector at various γ-ray energies emitted by standard radioactive point sources 241Am, 133Ba, 60Co, 137Cs, and 152Eu. The experimental values of the prepared mortars’ mass attenuation coefficients (MAC) match well with those determined theoretically from the XCOM database. Other shielding parameters, including half value layer (HVL), ten...
ABSTRACT In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of a... more ABSTRACT In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of activity when the sample to be measured is small and has low radioactivity, the well-type HPGe detectors are widely used. To determine the sample activity, the full-energy peak efficiency is needed. In this work, the efficiency transfer method (ET) in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for the HPGe well-type detector. This approach is based on the calculation of the effective solid angles ratio for a well-type detector with a cylindrical source inside and an axial point source outside the detector cavity, taking into account the attenuation of the gamma-rays. The calculated values of the full-energy peak efficiency are found to be in a good agreement with the measured experimental data obtained by using a mixed radionuclide gamma-ray source containing 60Co and 88Y.
In this work, morphological and attenuation parameters of gamma ray protection were studied. Dime... more In this work, morphological and attenuation parameters of gamma ray protection were studied. Dimethyl polysiloxane (Silicon Rubber) Mixed with micro-size and nano-size lead oxide particles at different weight percentage were prepared. The morphological structure of PbO/SR composites was investigated by SEM test, according to SEM images the nano PbO particles are more uniform micro PbO particles. The radiation attenuation test was carried out using 3ʺ × 3ʺ NaI (TI) detector for (Am-241), (Cs-137), (Co-60), (Ba-133), and (Eu-152). The effect on attenuation property of SR-PbO shown that the increase of PbO filler significantly increases the linear attenuation coefficient and improve the other radiation protection parameters especially at low gamma energy. It's found that a significant agreement between the experimental result and theoretical result from Xcom program. In this study it's found matrix filled with nano-PbO have higher gamma shielding ability compared to micro-PbO m...
ABSTRACT ABSTRACT: The high efficiency of well-type detector is one of its important advantages, ... more ABSTRACT ABSTRACT: The high efficiency of well-type detector is one of its important advantages, when it is used to determine the low level activity of radiation in many different fields. In the present work the full-energy peak efficiency of 3”x3” NaI(Tl) well-type scintillation detector was calculated. The calculations were based on the efficiency transfer principle and a new straightforward analytical definition to compute the effective solid angle between a point source and the detector surfaces Moreover, the effective solid angle ratio subtended by the well-type detector and a point source located out the detector cavity at various distances was calculated, the attenuation of the photon by the source-detector system [detectorendcap,deadlayer and holder material] was considered and determined. This method is easily useful in setting up the efficiency calibration curve for well-type detectors when the source is outside. The computed efficiency values are found to be in a good agreement with the experimental data obtained in the case of radiating g-ray standard point sources.
A new analytical approach is presented for the calculation of full-energy peak (FEP) efficiency o... more A new analytical approach is presented for the calculation of full-energy peak (FEP) efficiency of NaI (Tl) detectors. The self-attenuation of the parallelepiped source matrix, the attenuation by the source container, and the detector housing materials were considered in the mathematical treatment. The efficiency values calculated using the presently suggested analytical approach are compared with those measured values obtained by two different sizes of NaI (Tl) detectors. The calculated and the measured full-energy peak efficiency values were in a good agreement.
Natural rubber (NR)-loaded with the critical concentration (30phr) of N220 black and different co... more Natural rubber (NR)-loaded with the critical concentration (30phr) of N220 black and different concentrations of Lead (Pb) powder were prepared according to the standard method (ASTMD 3185 – (99)). All samples are subjected to the rheometric, mechanical, electrical, and physico-chemical measurements. It is noticed that upon increasing Pb content, minimum torque (ML) and maximum torque (MH) increase, while scorch time (Tsc) and cure time (T90) decrease. The mechanical parameters such as tensile strength (TS) and elongation at break (Eb) decrease, modulus at 300% (M 300 ) increases at 20 phr then decreases, whereas hardness markedly increases upon increasing Pb content. The morphology of Pb-loaded NR composites (Pb/NR) was examined to correlate with observations on mechanical properties by scanning electron microscopy (SEM). A relatively co-continuous morphology was observed for Pb/NR composites. The SEM analysis indicates that there has been a good compatibility within the rubber matrix. The maximum degree of swelling in benzene ( Q m (%))exhibits marked decrease while the crosslink density increases by increasing Pb content. Kinetic parameters such as elastic Gibbs free energy and conformational entropy were determined from Flory–Huggins kinetic model. Furthermore, the marked increase of dc conductivity ( σ dc ) is due to the increase of Pb content which is micro metallic and as a result of that, it is responsible for increasing the conductivity values. Finally, the measurements of σ ac as a function of frequency confirm the hopping conduction mechanism.
In this study, synthetic silicone rubber (SR) and Bi2O3 micro- and nanoparticles were purchased. ... more In this study, synthetic silicone rubber (SR) and Bi2O3 micro- and nanoparticles were purchased. The percentages for both sizes of Bi2O3 were 10, 20 and 30 wt% as fillers. The morphological, mechanical and shielding properties were determined for all the prepared samples. The Linear Attenuation Coefficient (LAC) values of the silicon rubber (SR) without Bi2O3 and with 5, 10, 30 and 30% Bi2O3 (in micro and nano sizes) were experimentally measured using different radioactive point sources in the energy range varying from 0.06 to 1.333 MeV. Additionally, we theoretically calculated the LAC for SR with micro-Bi2O3 using XCOM software. A good agreement was noticed between the two methods. The NaI (Tl) scintillation detector and four radioactive point sources (Am-241, Ba-133, Cs-137 and Co-60) were used in the measurements. Other shielding parameters were calculated for the prepared samples, such as the Half Value Layer (HVL), Mean Free Path (MFP) and Radiation Protection Efficiency (RPE)...
Journal of Engineering Science and Technology, 2017
A new mathematical solution for the geometrical and total efficiencies integrable equations of cy... more A new mathematical solution for the geometrical and total efficiencies integrable equations of cylindrical and spherical gamma-ray detectors is proposed. The efficiencies integrable equations are based on the accurate analytical computation of the photon path length traverses within the detector active medium, and the geometrical solid angle, Ω, subtended by the source to the detector at the point of entrance. The comparison between the efficiencies calculated values by the use of both, the integrable and direct solution formulae, showing very good agreement.
We prepared red clays by introducing different percentages of PbO, Bi2O3, and CdO. In order to un... more We prepared red clays by introducing different percentages of PbO, Bi2O3, and CdO. In order to understand how the introduction of these oxides into red clay influences its attenuation ability, the mass attenuation coefficient of the clays was experimentally measured in a lab using an HPGe detector. The theoretical shielding capability of the material present was obtained using XCOM to verify the accuracy of the experimental results. We found that the experimental and theoretical values agree to a very high degree of precision. The effective atomic number (Zeff) of pure red clay, and red clay with the three metal oxides was determined. The pure red clay had the lowest Zeff of the tested samples, which means that introducing any of these three oxides into the clay will greatly enhance its Zeff, and consequently its attenuation capability. Additionally, the Zeff for red clay with 10 wt% CdO is lower than the Zeff of red clay with 10 wt% Bi2O3 and PbO. We also prepared red clay using 10...
journal of engineering science and technology, 2017
A new mathematical solution for the geometrical and total efficiencies integrable equations of cy... more A new mathematical solution for the geometrical and total efficiencies integrable equations of cylindrical and spherical gamma-ray detectors is proposed. The efficiencies integrable equations are based on the accurate analytical computation of the photon path length traverses within the detector active medium, and the geometrical solid angle, Ω, subtended by the source to the detector at the point of entrance. The comparison between the efficiencies calculated values by the use of both, the integrable and direct solution formulae, showing very good agreement.
An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.
The gamma-ray shielding ability of various Bentonite–Cement mixed materials from northeast Egypt ... more The gamma-ray shielding ability of various Bentonite–Cement mixed materials from northeast Egypt have been examined by determining their theoretical and experimental mass attenuation coefficients, μm (cm2g−1), at photon energies of 59.6, 121.78, 344.28, 661.66, 964.13, 1173.23, 1332.5 and 1408.01 keV emitted from 241Am, 137Cs, 152Eu and 60Co point sources. The μm was theoretically calculated using the chemical compositions obtained by Energy Dispersive X-ray Analysis (EDX), while a NaI (Tl) scintillation detector was used to experimentally determine the μm (cm2g−1) of the mixed samples. The theoretical values are in acceptable agreement with the experimental calculations of the XCom software. The linear attenuation coefficient (μ), mean free path (MFP), half-value layer (HVL) and the exposure buildup factor (EBF) were also calculated by knowing the μm values of the examined samples. The gamma-radiation shielding ability of the selected Bentonite–Cement mixed samples have been studie...
The aim of this study is to investigate the radiation shielding properties of novel concrete samp... more The aim of this study is to investigate the radiation shielding properties of novel concrete samples with bulk Bi2O3 and Bi2O3 nanoparticles (Bi2O3 NP) incorporated into its composition. The mass attenuation coefficient of the concrete samples without Bi2O3 and with 5 and 7 wt% bulk Bi2O3 were experimentally determined and were compared against values obtained using the XCOM and Geant4 simulations. Both methods greatly agree with the experimental values. The linear attenuation coefficients (LAC) of blank concrete (C-0), concrete with 5% bulk Bi2O3 (C-B5), and concrete with 5% nanoparticle Bi2O3 (C-N5) were determined and compared at a wide energy range. We found that the LAC follows the trend of C-0 < C-B5 < C-N5 at all the tested energies. Since both C-B5 and C-N5 have a greater LAC than C-0, these results indicate that the addition of Bi2O3 improves the shielding ability of the concretes. In addition, we investigated the influence of nanoparticle Bi2O3 on the LAC of the conc...
This study aims to explore the radiation protection properties of white mortars based on white ce... more This study aims to explore the radiation protection properties of white mortars based on white cement as a binder and Bi2O3 micro and nanoparticles in proportions of 15 and 30% by weight as replacement sand. The average particle size of micro- and nano-Bi2O3 was measured using a transmission electron microscope (TEM). The cross-sectional morphology and distribution of Bi2O3 within the samples can be obtained by scanning electron microscopy (SEM), showing that nanoscale Bi2O3 particles have a more homogeneous distribution within the samples than microscale Bi2O3 particles. The shielding parameters of the proposed mortars were measured using the HPGe detector at various γ-ray energies emitted by standard radioactive point sources 241Am, 133Ba, 60Co, 137Cs, and 152Eu. The experimental values of the prepared mortars’ mass attenuation coefficients (MAC) match well with those determined theoretically from the XCOM database. Other shielding parameters, including half value layer (HVL), ten...
ABSTRACT In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of a... more ABSTRACT In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of activity when the sample to be measured is small and has low radioactivity, the well-type HPGe detectors are widely used. To determine the sample activity, the full-energy peak efficiency is needed. In this work, the efficiency transfer method (ET) in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for the HPGe well-type detector. This approach is based on the calculation of the effective solid angles ratio for a well-type detector with a cylindrical source inside and an axial point source outside the detector cavity, taking into account the attenuation of the gamma-rays. The calculated values of the full-energy peak efficiency are found to be in a good agreement with the measured experimental data obtained by using a mixed radionuclide gamma-ray source containing 60Co and 88Y.
In this work, morphological and attenuation parameters of gamma ray protection were studied. Dime... more In this work, morphological and attenuation parameters of gamma ray protection were studied. Dimethyl polysiloxane (Silicon Rubber) Mixed with micro-size and nano-size lead oxide particles at different weight percentage were prepared. The morphological structure of PbO/SR composites was investigated by SEM test, according to SEM images the nano PbO particles are more uniform micro PbO particles. The radiation attenuation test was carried out using 3ʺ × 3ʺ NaI (TI) detector for (Am-241), (Cs-137), (Co-60), (Ba-133), and (Eu-152). The effect on attenuation property of SR-PbO shown that the increase of PbO filler significantly increases the linear attenuation coefficient and improve the other radiation protection parameters especially at low gamma energy. It's found that a significant agreement between the experimental result and theoretical result from Xcom program. In this study it's found matrix filled with nano-PbO have higher gamma shielding ability compared to micro-PbO m...
ABSTRACT ABSTRACT: The high efficiency of well-type detector is one of its important advantages, ... more ABSTRACT ABSTRACT: The high efficiency of well-type detector is one of its important advantages, when it is used to determine the low level activity of radiation in many different fields. In the present work the full-energy peak efficiency of 3”x3” NaI(Tl) well-type scintillation detector was calculated. The calculations were based on the efficiency transfer principle and a new straightforward analytical definition to compute the effective solid angle between a point source and the detector surfaces Moreover, the effective solid angle ratio subtended by the well-type detector and a point source located out the detector cavity at various distances was calculated, the attenuation of the photon by the source-detector system [detectorendcap,deadlayer and holder material] was considered and determined. This method is easily useful in setting up the efficiency calibration curve for well-type detectors when the source is outside. The computed efficiency values are found to be in a good agreement with the experimental data obtained in the case of radiating g-ray standard point sources.
A new analytical approach is presented for the calculation of full-energy peak (FEP) efficiency o... more A new analytical approach is presented for the calculation of full-energy peak (FEP) efficiency of NaI (Tl) detectors. The self-attenuation of the parallelepiped source matrix, the attenuation by the source container, and the detector housing materials were considered in the mathematical treatment. The efficiency values calculated using the presently suggested analytical approach are compared with those measured values obtained by two different sizes of NaI (Tl) detectors. The calculated and the measured full-energy peak efficiency values were in a good agreement.
Natural rubber (NR)-loaded with the critical concentration (30phr) of N220 black and different co... more Natural rubber (NR)-loaded with the critical concentration (30phr) of N220 black and different concentrations of Lead (Pb) powder were prepared according to the standard method (ASTMD 3185 – (99)). All samples are subjected to the rheometric, mechanical, electrical, and physico-chemical measurements. It is noticed that upon increasing Pb content, minimum torque (ML) and maximum torque (MH) increase, while scorch time (Tsc) and cure time (T90) decrease. The mechanical parameters such as tensile strength (TS) and elongation at break (Eb) decrease, modulus at 300% (M 300 ) increases at 20 phr then decreases, whereas hardness markedly increases upon increasing Pb content. The morphology of Pb-loaded NR composites (Pb/NR) was examined to correlate with observations on mechanical properties by scanning electron microscopy (SEM). A relatively co-continuous morphology was observed for Pb/NR composites. The SEM analysis indicates that there has been a good compatibility within the rubber matrix. The maximum degree of swelling in benzene ( Q m (%))exhibits marked decrease while the crosslink density increases by increasing Pb content. Kinetic parameters such as elastic Gibbs free energy and conformational entropy were determined from Flory–Huggins kinetic model. Furthermore, the marked increase of dc conductivity ( σ dc ) is due to the increase of Pb content which is micro metallic and as a result of that, it is responsible for increasing the conductivity values. Finally, the measurements of σ ac as a function of frequency confirm the hopping conduction mechanism.
In this study, synthetic silicone rubber (SR) and Bi2O3 micro- and nanoparticles were purchased. ... more In this study, synthetic silicone rubber (SR) and Bi2O3 micro- and nanoparticles were purchased. The percentages for both sizes of Bi2O3 were 10, 20 and 30 wt% as fillers. The morphological, mechanical and shielding properties were determined for all the prepared samples. The Linear Attenuation Coefficient (LAC) values of the silicon rubber (SR) without Bi2O3 and with 5, 10, 30 and 30% Bi2O3 (in micro and nano sizes) were experimentally measured using different radioactive point sources in the energy range varying from 0.06 to 1.333 MeV. Additionally, we theoretically calculated the LAC for SR with micro-Bi2O3 using XCOM software. A good agreement was noticed between the two methods. The NaI (Tl) scintillation detector and four radioactive point sources (Am-241, Ba-133, Cs-137 and Co-60) were used in the measurements. Other shielding parameters were calculated for the prepared samples, such as the Half Value Layer (HVL), Mean Free Path (MFP) and Radiation Protection Efficiency (RPE)...
Journal of Engineering Science and Technology, 2017
A new mathematical solution for the geometrical and total efficiencies integrable equations of cy... more A new mathematical solution for the geometrical and total efficiencies integrable equations of cylindrical and spherical gamma-ray detectors is proposed. The efficiencies integrable equations are based on the accurate analytical computation of the photon path length traverses within the detector active medium, and the geometrical solid angle, Ω, subtended by the source to the detector at the point of entrance. The comparison between the efficiencies calculated values by the use of both, the integrable and direct solution formulae, showing very good agreement.
We prepared red clays by introducing different percentages of PbO, Bi2O3, and CdO. In order to un... more We prepared red clays by introducing different percentages of PbO, Bi2O3, and CdO. In order to understand how the introduction of these oxides into red clay influences its attenuation ability, the mass attenuation coefficient of the clays was experimentally measured in a lab using an HPGe detector. The theoretical shielding capability of the material present was obtained using XCOM to verify the accuracy of the experimental results. We found that the experimental and theoretical values agree to a very high degree of precision. The effective atomic number (Zeff) of pure red clay, and red clay with the three metal oxides was determined. The pure red clay had the lowest Zeff of the tested samples, which means that introducing any of these three oxides into the clay will greatly enhance its Zeff, and consequently its attenuation capability. Additionally, the Zeff for red clay with 10 wt% CdO is lower than the Zeff of red clay with 10 wt% Bi2O3 and PbO. We also prepared red clay using 10...
journal of engineering science and technology, 2017
A new mathematical solution for the geometrical and total efficiencies integrable equations of cy... more A new mathematical solution for the geometrical and total efficiencies integrable equations of cylindrical and spherical gamma-ray detectors is proposed. The efficiencies integrable equations are based on the accurate analytical computation of the photon path length traverses within the detector active medium, and the geometrical solid angle, Ω, subtended by the source to the detector at the point of entrance. The comparison between the efficiencies calculated values by the use of both, the integrable and direct solution formulae, showing very good agreement.
An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.
The gamma-ray shielding ability of various Bentonite–Cement mixed materials from northeast Egypt ... more The gamma-ray shielding ability of various Bentonite–Cement mixed materials from northeast Egypt have been examined by determining their theoretical and experimental mass attenuation coefficients, μm (cm2g−1), at photon energies of 59.6, 121.78, 344.28, 661.66, 964.13, 1173.23, 1332.5 and 1408.01 keV emitted from 241Am, 137Cs, 152Eu and 60Co point sources. The μm was theoretically calculated using the chemical compositions obtained by Energy Dispersive X-ray Analysis (EDX), while a NaI (Tl) scintillation detector was used to experimentally determine the μm (cm2g−1) of the mixed samples. The theoretical values are in acceptable agreement with the experimental calculations of the XCom software. The linear attenuation coefficient (μ), mean free path (MFP), half-value layer (HVL) and the exposure buildup factor (EBF) were also calculated by knowing the μm values of the examined samples. The gamma-radiation shielding ability of the selected Bentonite–Cement mixed samples have been studie...
The aim of this study is to investigate the radiation shielding properties of novel concrete samp... more The aim of this study is to investigate the radiation shielding properties of novel concrete samples with bulk Bi2O3 and Bi2O3 nanoparticles (Bi2O3 NP) incorporated into its composition. The mass attenuation coefficient of the concrete samples without Bi2O3 and with 5 and 7 wt% bulk Bi2O3 were experimentally determined and were compared against values obtained using the XCOM and Geant4 simulations. Both methods greatly agree with the experimental values. The linear attenuation coefficients (LAC) of blank concrete (C-0), concrete with 5% bulk Bi2O3 (C-B5), and concrete with 5% nanoparticle Bi2O3 (C-N5) were determined and compared at a wide energy range. We found that the LAC follows the trend of C-0 < C-B5 < C-N5 at all the tested energies. Since both C-B5 and C-N5 have a greater LAC than C-0, these results indicate that the addition of Bi2O3 improves the shielding ability of the concretes. In addition, we investigated the influence of nanoparticle Bi2O3 on the LAC of the conc...
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