جستجوی مقالات مرتبط با کلیدواژه "thallium-201" در نشریات گروه "فیزیک"

This study was performed with the aim of determination of dose calibrators’ accuracy in nuclear medicine centers. Thallium-201 radiopharmaceutical was used for comparison of dose calibrators with each other and with the reference. After the measurement which was carried out in 12 centers located in tehran and other cities, and according to the data obtained from the reference, it was concluded that dose calibrators in 10 centers are with positive and 2 centers with negative errors, as compared with the reference.

Thallium-201 is one of the medical radioisotopes produced in Nuclear Research Center for Agriculture and Medicine via 203Tl (p, 3n) 201Pb reaction, using protons from cyclotron Cyclone 30. Due to high intensity of the neutrons produced from the thallium target and its copper substrate, protection against this radiation is a necessity. The radiation shield is the concrete walls of the target room accessible from outside through a multi-bend maze. In this work, we have calculated the streaming of neutrons through the maze of the target room using MCNP Monte Carlo radiation transport code. The target has been bombarded with 145 µA of 28.5 MeV protons. Equivalent dose rate of neutrons in various positions in the maze has been calculated and compared with the measured values. The maximum deviation between the calculated and measured values is found to occur at the farthest position from the source, namely at the entrance door of the maze, for which the neutron equivalent dose has been calculated as 93 mSv/hr and the corrected measured value upon using the energy spectrum weighted correction factor is 136 mSv/hr. These values are in good agreement with each other according to the shielding point of view.