Total and full-energy peak efficiencies, coincidence correction factors and the source self-absor... more Total and full-energy peak efficiencies, coincidence correction factors and the source self-absorption of a p-type coaxial HPGe detector for cylindrical sources have been calculated using direct analytical expressions. In the experiments gamma aqueous sources containing several radionuclides covering the energy range from 60 to 1836 keV were used. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement.
Total and full-energy peak efficiencies, coincidence correction factors and the source self-absor... more Total and full-energy peak efficiencies, coincidence correction factors and the source self-absorption of a p-type coaxial HPGe detector for cylindrical sources have been calculated using direct analytical expressions. In the experiments gamma aqueous sources containing several radionuclides covering the energy range from 60 to 1836 keV were used. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement.
A new type of photon detector, log-conical, is proposed. The average path length traveled by an i... more A new type of photon detector, log-conical, is proposed. The average path length traveled by an incident photon of arbitrary energy as well as the geometrical solid angle are calculated in a mathematical expression to determine the efficiencies of this detector for an arbitrarily positioned isotropic radiating point source. The off-axis effect of the source position was analyzed to demonstrate
Total eÅciencies of clad right cylindrical NaI(Tl) scintillation detectors exposed to photons emi... more Total eÅciencies of clad right cylindrical NaI(Tl) scintillation detectors exposed to photons emitted by circular disk sources have been calculated by using rigid mathematical expressions. Results are tabulated for various gamma energies. # 1998 Elsevier Science Ltd. All rights reserved.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
... Mahmoud I. Abbas Corresponding Author Contact Information , a , E-mail The Corresponding Auth... more ... Mahmoud I. Abbas Corresponding Author Contact Information , a , E-mail The Corresponding Author. ... This approach is based on the direct mathematical method reported by Selim and Abbas [2], [3], [4], [5], [6], [7], [8], [9] and [10] and has been used successfully before to ...
Abstract The rate of diffusion of Zn into Fe in solid Fe/Zn diffusion couples is found to be two ... more Abstract The rate of diffusion of Zn into Fe in solid Fe/Zn diffusion couples is found to be two to four orders of magnitude greater than would be predicted by lattice diffusion. The penetration depth varies markedly from sample to sample. It is achieved primarily in an ...
The purpose of this study is to investigate some concepts regarding the role played by local airp... more The purpose of this study is to investigate some concepts regarding the role played by local airports in the economies of the regions they serve. The writers attempt to formulate a conceptual framework for the study of airports' economic development and/or growth effects on local economies. ...
A straightforward analytical formulae for the computation of total and full-energy peak efficienc... more A straightforward analytical formulae for the computation of total and full-energy peak efficiencies of NaI (Tl) and HPGe well-type detectors are deduced. In addition, the attenuation of photons by the source container and the detector end cap materials is presented in a direct mathematical expression. Results are compared with previous treatments.
Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all a... more Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all absolute measurements of the strengths of radioactive materials and to calibrate detectors. The method of high-efficiency γ counting by means of well-type HPGe and NaI (Tl) detectors is widely used and has proved a powerful tool, particularly when low-activity, small-volume environmental samples are to be analyzed by γ-ray spectrometry. In the present work, we introduce a direct analytical method for calculating the solid angle subtended by a well-type detector at axial point, non-axial point, extended circular disk and cylindrical sources. The validity of the derived analytical expressions was successfully confirmed by the comparisons with some published data (experimental and Monte Carlo).
Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all a... more Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all absolute measurements of the strengths of radioactive materials and to calibrate detectors. The method of high-efficiency γ counting by means of well-type HPGe and NaI (Tl) detectors is widely used and has proved a powerful tool, particularly when low-activity, small-volume environmental samples are to be analyzed by γ-ray spectrometry. In the present work, we introduce a direct analytical method for calculating the solid angle subtended by a well-type detector at axial point, non-axial point, extended circular disk and cylindrical sources. The validity of the derived analytical expressions was successfully confirmed by the comparisons with some published data (experimental and Monte Carlo).
Total and full-energy peak efficiencies, coincidence correction factors and the source self-absor... more Total and full-energy peak efficiencies, coincidence correction factors and the source self-absorption of a p-type coaxial HPGe detector for cylindrical sources have been calculated using direct analytical expressions. In the experiments gamma aqueous sources containing several radionuclides covering the energy range from 60 to 1836 keV were used. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement.
Total and full-energy peak efficiencies, coincidence correction factors and the source self-absor... more Total and full-energy peak efficiencies, coincidence correction factors and the source self-absorption of a p-type coaxial HPGe detector for cylindrical sources have been calculated using direct analytical expressions. In the experiments gamma aqueous sources containing several radionuclides covering the energy range from 60 to 1836 keV were used. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement.
A new type of photon detector, log-conical, is proposed. The average path length traveled by an i... more A new type of photon detector, log-conical, is proposed. The average path length traveled by an incident photon of arbitrary energy as well as the geometrical solid angle are calculated in a mathematical expression to determine the efficiencies of this detector for an arbitrarily positioned isotropic radiating point source. The off-axis effect of the source position was analyzed to demonstrate
Total eÅciencies of clad right cylindrical NaI(Tl) scintillation detectors exposed to photons emi... more Total eÅciencies of clad right cylindrical NaI(Tl) scintillation detectors exposed to photons emitted by circular disk sources have been calculated by using rigid mathematical expressions. Results are tabulated for various gamma energies. # 1998 Elsevier Science Ltd. All rights reserved.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
... Mahmoud I. Abbas Corresponding Author Contact Information , a , E-mail The Corresponding Auth... more ... Mahmoud I. Abbas Corresponding Author Contact Information , a , E-mail The Corresponding Author. ... This approach is based on the direct mathematical method reported by Selim and Abbas [2], [3], [4], [5], [6], [7], [8], [9] and [10] and has been used successfully before to ...
Abstract The rate of diffusion of Zn into Fe in solid Fe/Zn diffusion couples is found to be two ... more Abstract The rate of diffusion of Zn into Fe in solid Fe/Zn diffusion couples is found to be two to four orders of magnitude greater than would be predicted by lattice diffusion. The penetration depth varies markedly from sample to sample. It is achieved primarily in an ...
The purpose of this study is to investigate some concepts regarding the role played by local airp... more The purpose of this study is to investigate some concepts regarding the role played by local airports in the economies of the regions they serve. The writers attempt to formulate a conceptual framework for the study of airports' economic development and/or growth effects on local economies. ...
A straightforward analytical formulae for the computation of total and full-energy peak efficienc... more A straightforward analytical formulae for the computation of total and full-energy peak efficiencies of NaI (Tl) and HPGe well-type detectors are deduced. In addition, the attenuation of photons by the source container and the detector end cap materials is presented in a direct mathematical expression. Results are compared with previous treatments.
Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all a... more Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all absolute measurements of the strengths of radioactive materials and to calibrate detectors. The method of high-efficiency γ counting by means of well-type HPGe and NaI (Tl) detectors is widely used and has proved a powerful tool, particularly when low-activity, small-volume environmental samples are to be analyzed by γ-ray spectrometry. In the present work, we introduce a direct analytical method for calculating the solid angle subtended by a well-type detector at axial point, non-axial point, extended circular disk and cylindrical sources. The validity of the derived analytical expressions was successfully confirmed by the comparisons with some published data (experimental and Monte Carlo).
Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all a... more Knowledge of the solid angle (and consequently, the geometrical efficiency) is essential in all absolute measurements of the strengths of radioactive materials and to calibrate detectors. The method of high-efficiency γ counting by means of well-type HPGe and NaI (Tl) detectors is widely used and has proved a powerful tool, particularly when low-activity, small-volume environmental samples are to be analyzed by γ-ray spectrometry. In the present work, we introduce a direct analytical method for calculating the solid angle subtended by a well-type detector at axial point, non-axial point, extended circular disk and cylindrical sources. The validity of the derived analytical expressions was successfully confirmed by the comparisons with some published data (experimental and Monte Carlo).
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