부산대학교 도서관

The purpose of this study is to make a study of clinical characteristics and fading effect of CVD diamond detectors with different thickness as applying for radiotherapy. Measurements were performed for 6MV, 10MV photon and 6MeV, 9MeV, 12MeV, 15MeV electron with 0.2mm-CVD and 0.5mm-CVD. The CVD fading effect caused by indoor light in blight room and darkroom, and the linearity of dose response for 0cGy to 4000cGy were measured. We also measured the oblique factor caused by difference incident angle and the energy dependence factor of CVD for Co-60 and linear accelerator beams. Our results show that the indoor light will make CVD fading acutely. The fading effect is not obvious when reading is performed no more than 60 minutes after irradiating. The TL response decrease 49.24% for 0.5mm-CVD and 71.11% for 0.2mm-CVD as they were placed in bright room for 46 hours. The linearity of TL response of CVD is good for dose get up to 500cGy, the R-square values are 0.993 and 0.991 for 0.5mm-CVD and 0.2mm-CVD, respectively. As the CVD are irradiated up to 4000cGy, the R-square values are 0.995 and 0.991 respectively. The energy dependence factors of CVD for photon beam don’t vary greatly but vary greatly for 12MeV and 15MeV electron that energy dependence factors are greater than 1.04. Furthermore, the oblique factors also increase with increased incident angle.