Nahid Hajiloo; Mostafa Mohammadi; Omid N. Ghodsi; Hamideh Daneshvar; Soheil Moghtader
Abstract
The International Atomic Energy Agency (IAEA), sends dosimeters annually to Secondary Standard Dosimetry Laboratories (SSDL) around the world, to calibrate their radiation field. Therefore, they mainly send thermo-luminescent dosimeters as transfer dosimeters to the SSDL laboratories, to be irradiated ...
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The International Atomic Energy Agency (IAEA), sends dosimeters annually to Secondary Standard Dosimetry Laboratories (SSDL) around the world, to calibrate their radiation field. Therefore, they mainly send thermo-luminescent dosimeters as transfer dosimeters to the SSDL laboratories, to be irradiated under the requested conditions and sent back to the IAEA laboratories for reading. In this way, by reading the dosimeters, the uncertainty of the dosimetry carried out by SSDL and, consequently, the calibration of its radiation fields is determined. In this research, with the aim of feasibility of comparative dosimetry program by SSDL laboratory for radiation therapy centers, this program was carried out for a number of centers. In this way, TLD-700 thermoluminescence dosimeters were irradiated in the same conditions in the SSDL laboratory and also in the selected centers to a certain amount. After reading and applying the correction coefficients and calibration factors, the obtained results were compared with the measurement results using ion chamber reference dosimeter. In this work the uncertainty of the dosimetry using TLD tablet was less than 1.12% in comparison to the reference ionization chamber dosimeter and was within the acceptable range of less than 3%.
Nahid Hajiloo
Abstract
In this work, the impact of magnetic field presence on the central axis depth-dose curves of helium ion beams inside a heterogeneous phantom with air and bone layers was investigated. According to the calculations, presence of the magnetic field has a considerable impact on the dose distribution of helium ...
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In this work, the impact of magnetic field presence on the central axis depth-dose curves of helium ion beams inside a heterogeneous phantom with air and bone layers was investigated. According to the calculations, presence of the magnetic field has a considerable impact on the dose distribution of helium beams depending on the field strength and beam energy. A 32.3% abrupt increase and 92.5% reduction in dose were observed at the boundary between the water-air and the water-bone layer insert, respectively. The accuracy of the simulation was evaluated by verifying the depth dose curves of helium ion beams in a water phantom with experimental data.
