The cross-section ratios for the 59 Co(n,a) 56 Mn and 59 Co(n,2n) 58 Co reactions as well as for ... more The cross-section ratios for the 59 Co(n,a) 56 Mn and 59 Co(n,2n) 58 Co reactions as well as for the 90 Zr(n,2n) 89m+g Zr and 93 Nb(n,2n) 92m Nb reactions are usually used by the activation method for the purpose of neutron spectrometry around 14 MeV in a neutron generator having TiT target at fixed acceleration voltage 150 keV. The results are compared with the theoretically calculated values. Comparing the superiority of both the "Zr/Nbratio" method, and the " Cor 6 Mn-ratio" method is discussed.
The aerosol particles inside and beside the nuclear facilities in the ambient air are considered ... more The aerosol particles inside and beside the nuclear facilities in the ambient air are considered as the main causes of nuclear activities. These aerosols may be loaded with radioactive isotopes that adsorbed on its surface. Especially in the facility such a cyclotron where the radionuclides where produced and other production process be involved. The radioactivity registered due to elemental composition of indoor and outdoor air in radiation controlled areas are of drawback importance on the workers health, will be a good indicator for air quality and some health effects of workers in this facility. The analysis of the air samples was performed using γ-ray spectroscopy technique. The results show a similar composition of the indoor and outdoor dust which most of it has mineral origin. It was observed that the concentration of long lived radioactive isotopes such as 238 U, 226 Ra, and its daughter's increases in all indoor samples in detriment of a decrease in the concentration of these radioactive isotopes in the services laboratories, compared to hot laboratories. For the fission deliberated elements such as 137 Cs, 138 Cs, 131 I, 133 I, and 135 I only small traces were detected.
Manganese targets were performed. Excitation functions for the nat In(p,x) 113 Sn , 114m, 115m In... more Manganese targets were performed. Excitation functions for the nat In(p,x) 113 Sn , 114m, 115m In, nat Mn(p,x) 55 Fe, 54 Mn and 51 Cr from thresholds up to 17.4 MeV. Protons have been measured experimentally by the stacked-foil technique. High resolution HPGe gamma spectrometry have been used. Two stacks were irradiated by proton beams with energies 14.7 and 18 MeV for both Mn and In targets using the MGC-20 cyclotron at Nuclear Research Center (NRC), AEA, Egypt. The integral yields for 55 Fe, 54 Mn, 113 Sn, 114m In and 115m In at 16.5 MeV were found to be 0.28 , 0.17, 1.0, 0.02 and 10.0 MBq/A·h, respectively. The theoretical analysis of the excitation functions has been done employing both ALICE-IPPE and EMPIRE-2.19 codes. Theoretical calculations with the experimental data as well as the previously reported measurements are presented.
Thin target yields of 99m Tc radionuclide produced on accelerator by means of the reactions nat M... more Thin target yields of 99m Tc radionuclide produced on accelerator by means of the reactions nat Mo(p,x) from threshold up to 18 MeV are given. The experimental data have been measured employing the stacked foil activation technique. To the best of our knowledge the theoretical analysis of the excitation functions based on the EMPIRE-II code, used for the first time, gave good agree the theoretical and experimental data. This code could be used to predict the cross sections of the isomeric states for the 100 Mo(p,x) 99m Tc. Effects of various free parameters used in the calculations are also discussed. A significant contribution of pre-equilibrium CN component has been observed at these energies. Methods of cyclotron production of 99m Tc are considered.
The HPGe detector efficiency is measured as a function of source to detector separation using dis... more The HPGe detector efficiency is measured as a function of source to detector separation using disc sources of 131I with diameter ranging from 10 to 400 mm. Detector efficiencies are characterized using single photon point-like standard sources at different distances; the calculated efficiencies for disc sources were analyzed by utilizing the double point detector model (DPDM) and the efficiency transfer method. The developed approach provided satisfactory results. The axial variation and radial dependence for disc sources efficiency determination in gamma-ray spectrometry were described with bothgamma ray standard sources and measured samples as their extended sources.
The concept of double points detector model approach (DPDM) is developed as a procedure to find t... more The concept of double points detector model approach (DPDM) is developed as a procedure to find the full energy peak efficiency of the coaxial 120 cm3 closed hyperpure germanium (HPGe) detectors. Usually in the experimental nuclear physics work, which involves using HPGe detector for gamma-ray spectrometry, the full energy peak efficiency function must represent adequately the HPGe detector response. In the current work the gamma-ray energy in the range from 60 keV to 1332 keV and gamma-ray intensity changes by changing source to detector distance from 10 mm to 800 mm. The detector was characterized using a number of point-like standard sources. The calculated efficiencies obtained by (DPDM) are in good agreement with experimental data
The cross-section ratios for the 59 Co(n,a) 56 Mn and 59 Co(n,2n) 58 Co reactions as well as for ... more The cross-section ratios for the 59 Co(n,a) 56 Mn and 59 Co(n,2n) 58 Co reactions as well as for the 90 Zr(n,2n) 89m+g Zr and 93 Nb(n,2n) 92m Nb reactions are usually used by the activation method for the purpose of neutron spectrometry around 14 MeV in a neutron generator having TiT target at fixed acceleration voltage 150 keV. The results are compared with the theoretically calculated values. Comparing the superiority of both the "Zr/Nbratio" method, and the " Cor 6 Mn-ratio" method is discussed.
The aerosol particles inside and beside the nuclear facilities in the ambient air are considered ... more The aerosol particles inside and beside the nuclear facilities in the ambient air are considered as the main causes of nuclear activities. These aerosols may be loaded with radioactive isotopes that adsorbed on its surface. Especially in the facility such a cyclotron where the radionuclides where produced and other production process be involved. The radioactivity registered due to elemental composition of indoor and outdoor air in radiation controlled areas are of drawback importance on the workers health, will be a good indicator for air quality and some health effects of workers in this facility. The analysis of the air samples was performed using γ-ray spectroscopy technique. The results show a similar composition of the indoor and outdoor dust which most of it has mineral origin. It was observed that the concentration of long lived radioactive isotopes such as 238 U, 226 Ra, and its daughter's increases in all indoor samples in detriment of a decrease in the concentration of these radioactive isotopes in the services laboratories, compared to hot laboratories. For the fission deliberated elements such as 137 Cs, 138 Cs, 131 I, 133 I, and 135 I only small traces were detected.
Manganese targets were performed. Excitation functions for the nat In(p,x) 113 Sn , 114m, 115m In... more Manganese targets were performed. Excitation functions for the nat In(p,x) 113 Sn , 114m, 115m In, nat Mn(p,x) 55 Fe, 54 Mn and 51 Cr from thresholds up to 17.4 MeV. Protons have been measured experimentally by the stacked-foil technique. High resolution HPGe gamma spectrometry have been used. Two stacks were irradiated by proton beams with energies 14.7 and 18 MeV for both Mn and In targets using the MGC-20 cyclotron at Nuclear Research Center (NRC), AEA, Egypt. The integral yields for 55 Fe, 54 Mn, 113 Sn, 114m In and 115m In at 16.5 MeV were found to be 0.28 , 0.17, 1.0, 0.02 and 10.0 MBq/A·h, respectively. The theoretical analysis of the excitation functions has been done employing both ALICE-IPPE and EMPIRE-2.19 codes. Theoretical calculations with the experimental data as well as the previously reported measurements are presented.
Thin target yields of 99m Tc radionuclide produced on accelerator by means of the reactions nat M... more Thin target yields of 99m Tc radionuclide produced on accelerator by means of the reactions nat Mo(p,x) from threshold up to 18 MeV are given. The experimental data have been measured employing the stacked foil activation technique. To the best of our knowledge the theoretical analysis of the excitation functions based on the EMPIRE-II code, used for the first time, gave good agree the theoretical and experimental data. This code could be used to predict the cross sections of the isomeric states for the 100 Mo(p,x) 99m Tc. Effects of various free parameters used in the calculations are also discussed. A significant contribution of pre-equilibrium CN component has been observed at these energies. Methods of cyclotron production of 99m Tc are considered.
The HPGe detector efficiency is measured as a function of source to detector separation using dis... more The HPGe detector efficiency is measured as a function of source to detector separation using disc sources of 131I with diameter ranging from 10 to 400 mm. Detector efficiencies are characterized using single photon point-like standard sources at different distances; the calculated efficiencies for disc sources were analyzed by utilizing the double point detector model (DPDM) and the efficiency transfer method. The developed approach provided satisfactory results. The axial variation and radial dependence for disc sources efficiency determination in gamma-ray spectrometry were described with bothgamma ray standard sources and measured samples as their extended sources.
The concept of double points detector model approach (DPDM) is developed as a procedure to find t... more The concept of double points detector model approach (DPDM) is developed as a procedure to find the full energy peak efficiency of the coaxial 120 cm3 closed hyperpure germanium (HPGe) detectors. Usually in the experimental nuclear physics work, which involves using HPGe detector for gamma-ray spectrometry, the full energy peak efficiency function must represent adequately the HPGe detector response. In the current work the gamma-ray energy in the range from 60 keV to 1332 keV and gamma-ray intensity changes by changing source to detector distance from 10 mm to 800 mm. The detector was characterized using a number of point-like standard sources. The calculated efficiencies obtained by (DPDM) are in good agreement with experimental data
Uploads
Papers by Mohsen Challan