The purpose of this study is to estimate internal dose to human body due to administration of I-131 using new biokinetic model of iodine. In this respect, we used international commission on radiological protection (ICRP) adult reference phantoms. Monte Carlo calculations were performed using MCNPX 2.6 code. The average dose to target organ per disintegration inside source organ, namely S facto...

Recently, a new Neutron Radiography (NR) beam line has been designed, constricted, installed and tested based on the use of E-beam tube of Tehran Research Reactor (TRR). Initial tests have been shown that the system can be used for different samples and purposes such as nuclear plates and rods fuels.  For this end the system need a suitable irradiation room which should be installed at the NR b...

A new model is presented herein to calculate optimal value for ultra-cold neutron (UCN) production rate of a UCN source. The cold neutron (CN) converter is the main component of UCN source. In this paper, we study the UCN source which contains the D2O neutron moderator, the sD2 converter, 590 Mev proton beam, and the spallation target (a mixture of Pb, D2O and Zr). In order to determine the qua...

Medical linear accelerators (linacs) are used efficiently in radiation therapy for tumor treatments. In these devices interaction of high energy photons (greater than 7 MeV) with the target, flattening filters, collimators and even body and patients bed produce secondary particles such as neutrons(photo-neutron production). The purpose of this study is measuring the neutrons dose produced in me...

The purpose of this study is to determine the dosimetric parameters of a new 125I brachytherapy seed model, using Monte Carlo (MC) simulations according to the TG-43U1 recommendation. The Monte Carlo simulated dosimetric parameters of this sourse have been provided with MCNPX v.2.6 code. The source contains a cylindrical Ag+Al2O3 marker which is located at the center of the seed and onto which...

The source energy effect on the quality of counting profile obtained using gamma ray scanning technique was investigated. A lab-scale tray type column (one-pass tray type with 51 cm diameter) along with a 1×1 inch NaI(Tl) has been applied to investigate the source energy effect. MCNPX Monte Carlo code was used to simulate the column in normal and abnormal operating conditions. Cs-137 and ...