A Mercury (Ii) Oxide Dosimeter For Locating The Radioactive Source In Industrial Radiography Equipment

The gamma projector used in the NDT radiographic testing field is exposed to radiation sources due to equipment aging and user carelessness. Therefore, evaluations using various photoconductor materials, such as a dosimeter to confirm the location of the source have been carried out. However, since HgO has unstable electrical properties caused by oxidation in the air, it is difficult to evaluate its performance of radiation measurement. In this study, to solve this problem, a 1 cmx1 cm unit cell sensor was fabricated and a passive layer of 10 similar to 30 mu m thickness was formed using parylene. Then, the drift current and sensitivity according to the input voltage were evaluated to present the electrical characteristics, and the reproducibility, linearity, and PID were evaluated to show the performance. The electrical characteristics of the fabricated HgO dosimeter showed that the drift current decreased as the passive layer thickness increased, and the input voltage for optimum performance was -250 V. Reproducibility satisfies the criteria within 1.5% by showing an RSD of 1.39% at 30 mu m thickness. Linearity showed R-2 above 0.9990 in all sensors. In addition, the maximum measurement distance evaluated by PID was 12.9 cm. The results of this study suggest that HgO can be used as a candidate photoconductor material in various measurement fields. This study has great significance in evaluating the electrical properties and measurement performance of HgO.