Development Of Dosimeter With Line Arrayed Pixels For Radioactive Source Tracking System To Improve Radiation Safety

Radioisotopes such as Co-60 and Ir-192 are widely used in the field of non-destructive testing (NDT); thus, radiation safety control is becoming very important. In this study, the applicability of Mercury (II) Iodide (HgI2) to the source tracking system was evaluated. After evaluating the electrical characteristics of the line arrayed dosimeter based on HgI2, to verify the reliability, the characteristics of the position tracking of Ir-192 were analyzed. The results show that the reproducibility (RSD) was equal to or lower than 0.015 and linearity (R-sq) was equal to or higher than 0.99, which indicates high reliability. The maximum measurement distance was defined as 6.780 cm through the percentage interval distance evaluation. In the position sensitivity evaluation, the variation in the sensitivity of the signal with respect to the position of the source and peak value interval for each pixel corresponding to its actual isocenter interval was measured. Furthermore, based on this, the outputs of all pixels were normalized by calculating and applying the correction factor for each pixel. However, as the distance from the isocenter increased, the signal deviation between pixels tended to increase. This is likely to be caused by the degradation of the signal due to dose reduction and the increase in the relative noise effect. These results are expected to enable the development of a dosimeter capable of 2-dimentional tracking of radioactive sources with improved position sensitivity.