New types of mortar, M1 (60% sand, 25% cement, 10% ball clay, and 15% WO3), M2 (50% sand, 25% cem... more New types of mortar, M1 (60% sand, 25% cement, 10% ball clay, and 15% WO3), M2 (50% sand, 25% cement, 10% ball clay, and 25% WO3), M3 (60% sand, 25% cement, 10% Barite, and 15% WO3), and M4 (50% sand, 25% cement, 10% Barite, and 25% WO3), were prepared and the impact of WO3 and barite on their radiation shielding performance and mechanical properties was evaluated. The radiation attenuation factors were evaluated using five radioactive point sources, and a sodium iodide (NaI) scintillation detector (3″ × 3″) was used to detect the attenuation of gamma ray photons emitted from radioactive sources. The density values of the mortar samples lie within the range of 2.358 and 2.602 g/cm3. The compressive strength and the tensile strength of the prepared mortars increased with the increasing percentage of WO3. The M4 mortar had the highest linear attenuation coefficient (LAC) value. The LAC results demonstrated that adding barite and a high percentage of WO3 into the mortars notably enhanc...
Polymers are often used in medical applications, therefore, some novel polymers and their interac... more Polymers are often used in medical applications, therefore, some novel polymers and their interactions with photons have been studied. The gamma-ray shielding parameters for Polymethylpentene (PMP), Polybutylene terephthalate (PBT), Polyoxymethylene (POM), Polyvinylidenefluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE) polymers were determined using the Geant4 simulation and discussed in the current work. The mass attenuation coefficients (μ/ρ) were simulated at low and high energies between 0.059 and 1.408 MeV using different radionuclides. The accuracy of the Geant4 simulated results were checked with the XCOM software. The two different methods had good agreement with each other. Exposure buildup factor (EBF) was calculated and discussed in terms of polymers under study and photon energy. Effective atomic number (Zeff) and electron density (Neff) were calculated and analyzed at different energies. Additionally, the half-value layer (HVL) of the polymers was evaluated, and ...
The gamma radiation shielding ability for CaO-K2O-Na2O-P2O5 glasses were experimentally determine... more The gamma radiation shielding ability for CaO-K2O-Na2O-P2O5 glasses were experimentally determined between 0.0595 and 1.41 MeV. The experimental MAC results were compared with theoretical results obtained from the XCOM software to test the accuracy of the experimental values. Additionally, the effect of increasing the P2O5 in the glass composition, or reducing the Na2O content, was evaluated at varying energies. For the fabricated glasses, the experimental data strongly agreed with the XCOM results. The effective atomic number (Zeff) of the fabricated glasses was also determined. The Zeff values start out at their maximum (12.41–12.55) at the lowest tested energy, 0.0595 MeV, and decrease to 10.69–10.80 at 0.245 MeV. As energy further increases, the Zeff values remain almost constant between 0.344 and 1.41 MeV. The mean free path (MFP) of the fabricated glasses is investigated and we found that the lowest MFP value occurs at the lowest tested energy, 0.0595 MeV, and lies within the ...
A novel material was designed using layer-by-layer functionalization of nanobentonite with nanopo... more A novel material was designed using layer-by-layer functionalization of nanobentonite with nanopolyaniline and oleic acid to produce an efficient NBent-NPA-OA nanosorbent to adsorb the divalent ionic Zn/Co and their radioisotopes (65)Zn/(60)Co from tap water and radioactive wastewater. The new nanosorbent was characterized by Fourier-transform-infrared (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and determination of surface area. The NBent-NPA-OA particle size was ranged between 9.45 and 33.60nm according to HR-TEM analysis. The FT-IR exhibited several characteristic absorption peaks due to the existence of deposited layers of nanopolyaniline and oleic acid on the surface of nanobentonite surface. Different experimental parameters including, initial pH, contact time, nanosorbent, initial concentration of the target metals and interfering ions were varied, investiga...
The full energy peak efficiency (FEPE) of two γ-detectors by using radioactive parallelepiped sou... more The full energy peak efficiency (FEPE) of two γ-detectors by using radioactive parallelepiped sources is computed using a new analytical approach. The approach based on the efficiency transfer method (ET), the effective solid angles and explains the effect of self– absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive parallelepiped sources containing aqueous Eu-152 radionuclide which produces photons with a wide range of energies from 121 up to 1408 keV. The comparison shows a good agreement between the measured and calculated efficiencies for the detector using parallelepiped sources.
ABSTRACT In this work, the full energy peak efficiency for a system of two NaI gamma detectors us... more ABSTRACT In this work, the full energy peak efficiency for a system of two NaI gamma detectors using spherical radioactive sources is evaluated by applying a new numerical algorithm method, since experimental calibration using volumetric sources is a dominant problem of practical gamma spectrometry. The new method is based on the efficiency transfer technique, where the effective solid angles, the effect of self-absorption of the source matrix, and absorption by the source container and the detector housing materials on detector efficiency are considered. The experimental calibration procedure was done using radioactive spherical sources containing aqueous Eu-152 radionuclide, which produces photons with a wide range of energies from 121.78 up to 1408.03 keV. The comparison shows good agreement between the measured and calculated efficiencies for the detector using spherical sources.
ABSTRACT This work provides an approach to determine the efficiency of γ-ray detectors with a goo... more ABSTRACT This work provides an approach to determine the efficiency of γ-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficiency transfer formula (ET), the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive (Cylindrical & Marinelli) sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the (NaI & HPGe) detectors using volumetric radioactive sources.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013
ABSTRACT The present work investigates the validity of extending the efficiency transfer techniqu... more ABSTRACT The present work investigates the validity of extending the efficiency transfer technique (ET) to accommodate detection system composed of more than one detector [two NaI (Tl) detectors]. An arbitrary located radioactive point and volumetric cylindrical sources [152Eu aqueous radioactive sources covering the energy range from 121 keV up to 1408 keV] were used in order to get the full-energy peak efficiency (FEPE) based on the effective solid angle ratio. In addition, self attenuation of source matrix, the attenuation by the source container and the detector housing materials are also treated. Results are compared with those measured by a combination of two NaI(Tl) detectors of different volumes (3″×3″ and 2″×2″) with resolution (FWHM) at 662 keV equal to 7.5% and 8.5% respectively. The comparison between the calculated and the measured full-energy peak efficiency values reveal a good agreement.
A new theoretical approach was used to calibrate and calculate the full-energy peak efficiency of... more A new theoretical approach was used to calibrate and calculate the full-energy peak efficiency of the NaI (Tl) detectors based on the direct statistical method proposed by Selim and Abbas for cylindrical detectors. In addition, the self-attenuation of the source matrix, the attenuation by the source container and the detector housing materials were considered in the mathematical treatment. Results were compared with those measured by a cylindrical NaI (Tl) detector with resolution (FWHM) at 662 keV equal to 7.5 %. (152)Eu aqueous radioactive spherical sources covering the energy range from 121 to 1408 keV were used. In comparison, the calculated and the measured full-energy peak efficiency values were in good agreement.
The change in electrical properties of TGS crystals due to induced defects created by fast neutro... more The change in electrical properties of TGS crystals due to induced defects created by fast neutron irradiation of two different energies (2 and 14 MeV) and different integrated neutron fluxes have been studied in the vicinity of phase transition. It is observed that the electrical conductivity increases with increase of neutron fluence up to 1.7 × 10 n · cm
The influence of fast neutron irradiation of different energies (2 and 14 MeV) and neutron integr... more The influence of fast neutron irradiation of different energies (2 and 14 MeV) and neutron integrated flux on triglycine sulphate, TGS, single crystal has been studied during the measurements of the thermal expansion coefficient αii (i=1,2,3). A remarkable change in thermal expansion coefficient αii was observed in the vicinity of Curie temperature Tc with the change of neutron integrated flux.
To calibrate the co-axial HPGe semiconductor detectors, we introduce a new theoretical approach b... more To calibrate the co-axial HPGe semiconductor detectors, we introduce a new theoretical approach based on the Direct Statistical method proposed by Selim and Abbas (1995, 1996) to calculate the full-energy peak efficiency for cylindrical detectors. The present method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the geometrical solid angle Ω, to obtain a simple formula for the efficiency. In addition, the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius), the attenuation factors of the source container and the detector housing materials are also treated by calculating the average path length within these materials. (152)Eu aqueous radioactive sources covering the energy range from 121 to 1408 keV were used. Remarkable agreement between the measured and the calculated efficiencies was achieved with discrepancies less than 2%.
New types of mortar, M1 (60% sand, 25% cement, 10% ball clay, and 15% WO3), M2 (50% sand, 25% cem... more New types of mortar, M1 (60% sand, 25% cement, 10% ball clay, and 15% WO3), M2 (50% sand, 25% cement, 10% ball clay, and 25% WO3), M3 (60% sand, 25% cement, 10% Barite, and 15% WO3), and M4 (50% sand, 25% cement, 10% Barite, and 25% WO3), were prepared and the impact of WO3 and barite on their radiation shielding performance and mechanical properties was evaluated. The radiation attenuation factors were evaluated using five radioactive point sources, and a sodium iodide (NaI) scintillation detector (3″ × 3″) was used to detect the attenuation of gamma ray photons emitted from radioactive sources. The density values of the mortar samples lie within the range of 2.358 and 2.602 g/cm3. The compressive strength and the tensile strength of the prepared mortars increased with the increasing percentage of WO3. The M4 mortar had the highest linear attenuation coefficient (LAC) value. The LAC results demonstrated that adding barite and a high percentage of WO3 into the mortars notably enhanc...
Polymers are often used in medical applications, therefore, some novel polymers and their interac... more Polymers are often used in medical applications, therefore, some novel polymers and their interactions with photons have been studied. The gamma-ray shielding parameters for Polymethylpentene (PMP), Polybutylene terephthalate (PBT), Polyoxymethylene (POM), Polyvinylidenefluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE) polymers were determined using the Geant4 simulation and discussed in the current work. The mass attenuation coefficients (μ/ρ) were simulated at low and high energies between 0.059 and 1.408 MeV using different radionuclides. The accuracy of the Geant4 simulated results were checked with the XCOM software. The two different methods had good agreement with each other. Exposure buildup factor (EBF) was calculated and discussed in terms of polymers under study and photon energy. Effective atomic number (Zeff) and electron density (Neff) were calculated and analyzed at different energies. Additionally, the half-value layer (HVL) of the polymers was evaluated, and ...
The gamma radiation shielding ability for CaO-K2O-Na2O-P2O5 glasses were experimentally determine... more The gamma radiation shielding ability for CaO-K2O-Na2O-P2O5 glasses were experimentally determined between 0.0595 and 1.41 MeV. The experimental MAC results were compared with theoretical results obtained from the XCOM software to test the accuracy of the experimental values. Additionally, the effect of increasing the P2O5 in the glass composition, or reducing the Na2O content, was evaluated at varying energies. For the fabricated glasses, the experimental data strongly agreed with the XCOM results. The effective atomic number (Zeff) of the fabricated glasses was also determined. The Zeff values start out at their maximum (12.41–12.55) at the lowest tested energy, 0.0595 MeV, and decrease to 10.69–10.80 at 0.245 MeV. As energy further increases, the Zeff values remain almost constant between 0.344 and 1.41 MeV. The mean free path (MFP) of the fabricated glasses is investigated and we found that the lowest MFP value occurs at the lowest tested energy, 0.0595 MeV, and lies within the ...
A novel material was designed using layer-by-layer functionalization of nanobentonite with nanopo... more A novel material was designed using layer-by-layer functionalization of nanobentonite with nanopolyaniline and oleic acid to produce an efficient NBent-NPA-OA nanosorbent to adsorb the divalent ionic Zn/Co and their radioisotopes (65)Zn/(60)Co from tap water and radioactive wastewater. The new nanosorbent was characterized by Fourier-transform-infrared (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and determination of surface area. The NBent-NPA-OA particle size was ranged between 9.45 and 33.60nm according to HR-TEM analysis. The FT-IR exhibited several characteristic absorption peaks due to the existence of deposited layers of nanopolyaniline and oleic acid on the surface of nanobentonite surface. Different experimental parameters including, initial pH, contact time, nanosorbent, initial concentration of the target metals and interfering ions were varied, investiga...
The full energy peak efficiency (FEPE) of two γ-detectors by using radioactive parallelepiped sou... more The full energy peak efficiency (FEPE) of two γ-detectors by using radioactive parallelepiped sources is computed using a new analytical approach. The approach based on the efficiency transfer method (ET), the effective solid angles and explains the effect of self– absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive parallelepiped sources containing aqueous Eu-152 radionuclide which produces photons with a wide range of energies from 121 up to 1408 keV. The comparison shows a good agreement between the measured and calculated efficiencies for the detector using parallelepiped sources.
ABSTRACT In this work, the full energy peak efficiency for a system of two NaI gamma detectors us... more ABSTRACT In this work, the full energy peak efficiency for a system of two NaI gamma detectors using spherical radioactive sources is evaluated by applying a new numerical algorithm method, since experimental calibration using volumetric sources is a dominant problem of practical gamma spectrometry. The new method is based on the efficiency transfer technique, where the effective solid angles, the effect of self-absorption of the source matrix, and absorption by the source container and the detector housing materials on detector efficiency are considered. The experimental calibration procedure was done using radioactive spherical sources containing aqueous Eu-152 radionuclide, which produces photons with a wide range of energies from 121.78 up to 1408.03 keV. The comparison shows good agreement between the measured and calculated efficiencies for the detector using spherical sources.
ABSTRACT This work provides an approach to determine the efficiency of γ-ray detectors with a goo... more ABSTRACT This work provides an approach to determine the efficiency of γ-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficiency transfer formula (ET), the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive (Cylindrical & Marinelli) sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the (NaI & HPGe) detectors using volumetric radioactive sources.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013
ABSTRACT The present work investigates the validity of extending the efficiency transfer techniqu... more ABSTRACT The present work investigates the validity of extending the efficiency transfer technique (ET) to accommodate detection system composed of more than one detector [two NaI (Tl) detectors]. An arbitrary located radioactive point and volumetric cylindrical sources [152Eu aqueous radioactive sources covering the energy range from 121 keV up to 1408 keV] were used in order to get the full-energy peak efficiency (FEPE) based on the effective solid angle ratio. In addition, self attenuation of source matrix, the attenuation by the source container and the detector housing materials are also treated. Results are compared with those measured by a combination of two NaI(Tl) detectors of different volumes (3″×3″ and 2″×2″) with resolution (FWHM) at 662 keV equal to 7.5% and 8.5% respectively. The comparison between the calculated and the measured full-energy peak efficiency values reveal a good agreement.
A new theoretical approach was used to calibrate and calculate the full-energy peak efficiency of... more A new theoretical approach was used to calibrate and calculate the full-energy peak efficiency of the NaI (Tl) detectors based on the direct statistical method proposed by Selim and Abbas for cylindrical detectors. In addition, the self-attenuation of the source matrix, the attenuation by the source container and the detector housing materials were considered in the mathematical treatment. Results were compared with those measured by a cylindrical NaI (Tl) detector with resolution (FWHM) at 662 keV equal to 7.5 %. (152)Eu aqueous radioactive spherical sources covering the energy range from 121 to 1408 keV were used. In comparison, the calculated and the measured full-energy peak efficiency values were in good agreement.
The change in electrical properties of TGS crystals due to induced defects created by fast neutro... more The change in electrical properties of TGS crystals due to induced defects created by fast neutron irradiation of two different energies (2 and 14 MeV) and different integrated neutron fluxes have been studied in the vicinity of phase transition. It is observed that the electrical conductivity increases with increase of neutron fluence up to 1.7 × 10 n · cm
The influence of fast neutron irradiation of different energies (2 and 14 MeV) and neutron integr... more The influence of fast neutron irradiation of different energies (2 and 14 MeV) and neutron integrated flux on triglycine sulphate, TGS, single crystal has been studied during the measurements of the thermal expansion coefficient αii (i=1,2,3). A remarkable change in thermal expansion coefficient αii was observed in the vicinity of Curie temperature Tc with the change of neutron integrated flux.
To calibrate the co-axial HPGe semiconductor detectors, we introduce a new theoretical approach b... more To calibrate the co-axial HPGe semiconductor detectors, we introduce a new theoretical approach based on the Direct Statistical method proposed by Selim and Abbas (1995, 1996) to calculate the full-energy peak efficiency for cylindrical detectors. The present method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the geometrical solid angle Ω, to obtain a simple formula for the efficiency. In addition, the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius), the attenuation factors of the source container and the detector housing materials are also treated by calculating the average path length within these materials. (152)Eu aqueous radioactive sources covering the energy range from 121 to 1408 keV were used. Remarkable agreement between the measured and the calculated efficiencies was achieved with discrepancies less than 2%.
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Papers by Ahmed El-Khatib