Energy and angular dependence of the small-type OSL dosimeter in nuclear medicine regions using Monte Carlo simulation

Abstract

Radiation doses received by patients and medical staff from examinations using X-rays and radioactive materials have been increasing, and a reliable radiation dosimetry system is a necessity. An OSL dosimeter can be used and applied in such situations. However at this time, its property for nuclear medicine region is unclear. When we calculate the basic properties in this region using the Monte-Carlo simulation code, the consideration of secondary electron equilibrium is important. The aim of this study is to propose a compact irradiation system for simulation study, and use it to evaluate the energy and angular dependence of the small-type OSL dosimeter. The proposed system uses a phantom of acrylic and we examined which phantom thickness will be used considering the accuracy of the simulation and the contamination from scattered rays. Then, this system was applied to determine angular and energy dependences of the small-type OSL dosimeter. Experiments using the OSL dosimeter were performed in order to check the accuracy of the simulations. In addition when simulating the response of the OSL dosimeter, we determined the basic parameters of the detection material. We performed several situations, and concluded that the following parameters were in good agreement with the experiment: a detection layer of 100% Al2O3 with a density of 1.41 g/cm3.