Lead Oxide Mixture Detector Using Parylene C Type Layer for Improved Stability in High-Energy Computed Tomography

摘要

High-energy cone-beam computed tomography scanning has received much attention in the field of non-destructive testing of heavy equipment, and large-area two dimensional detectors have been actively studied. In this work, to improve image quality of high energy radiation detector, we fabricated a unit cell sensor that includes an insulator layer by using parylene C type material and investigated its characteristics. PbI2 was used as the photoconductor, and by adding PbO, we aimed to improve the stability of the image quality and P/D ratio. In terms of reproducibility, the mixture sensor showed improved results compared to the pure sensor, with relative standard deviations of 0.13% at 2 MeV and 0.62% at 5 MeV. In terms of linearity, the R-sq values of the pure and mixture sensors were more than 0.9999, with excellent linearity and slightly higher sensitivity for the pure sensor. The mixture sensor showed a photocurrent/drift current (P/D) ratio 2 times higher than that of the pure sensor when the drift current was relatively low. Therefore, the results of the present study indicate the possibility of improving sensor stability and image quality for image detection through the formation of a passive layer in mixture sensors.