An international journal published by K. N. Toosi University of Technology

Document Type : Research Article


1 Department of Radiation Application, Shahid Beheshti University, Tehran, Iran

2 Reactor and Nuclear Safety Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran


 The neutron transmutation doping method is widely used in various fields, such as solar cells, hybrid cars, etc. The Silicon doping process can provide direct commercial income for nuclear research reactors. In this study, we aim to find the optimal location for silicon doping in the thermal column nose of the Tehran research reactor. For this purpose, computational MCNPX and ORIGEN2 codes were used to calculate the neutronic and radioactivity parameters of the silicon ingot. The important parameters such as the thermal to fast neutron ratio, heat deposition by gamma and neutron, and the radioactivity level of the silicon ingot and the produced radioisotopes have been determined to obtain the optimal irradiation channel. The results showed that the irradiation channel placed in the thermal column at a distance of 90 cm from the center of the TRR core has optimal conditions for the implementation of silicon doping. The channel provides a thermal neutron flux in order of 1.721012‎-1‎ which is the least acceptable value to achieve a proposed neutron fluence during the operation cycles of TRR reactor. Also, the channel has the least possible heat deposition inside the silicon ingot of about 191 W. In addition, the thermal to fast neutron flux ratio of about 311 is enough higher than the determined IAEA limit for NTD.


  • Optimal location for silicon doping in the thermal column of the TRR has been investigated.
  • Parameters such as the thermal to fast neutron ratio and heat deposition by gamma and neutron have been obtained.
  • The activity level of the silicon ingot and the produced radioisotopes have been obtained.
  • The parameters have been determined based on Monte Carlo calculations.
  • The P-32 radioactivity level must be lower than the allowed value determined by IEAE.


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