Effects of Fully Filling Deep Electron/Hole Traps in Optically Stimulated Luminescence Dosimeters in the Kilovoltage Energy Range

• Published in: Journal of radiation protection and research Vol. 47; no. 3; pp. 134 - 142
• Main Authors: Chun, Minsoo, Jin, Hyeongmin, Lee, Sung Young, Kwon, Ohyun, Choi, Chang Heon, Park, Jong Min, Kim, Jung-in
• Format: Journal Article
• Language: Korean
• Published: 2022
• Subjects: kGy Pre-irradiation; OSL Dosimeters in kV Ranges; Dose Sensitivity; Deep Electron/Hole Trap
• ISSN: 2508-1888; 2466-2461

Background: This study investigated the characteristics of optically stimulated luminescence dosimeters (OSLDs) with fully filled deep electron/hole traps in the kV energy ranges. Materials and Methods: The experimental group consisted of InLight nanoDots, whose deep electron/hole traps were fully filled with 5 kGy pre-irradiation (OSLDexp), whereas the non-pre-irradiated OSLDs were arranged as a control group (OSLDcont). Absorbed doses for 75, 80, 85, 90, 95, 100, and 105 kVp with 200 mA and 40 ms were measured and defined as the unit doses for each energy value. A bleaching device equipped with a 520-nm long-pass filter was used, and the strong beam mode was used to read out signal counts. The characteristics were investigated in terms of fading, dose sensitivities according to the accumulated doses, and dose linearity. Results and Discussion: In OSLDexp, the average normalized counts (sensitivities) were 12.7%, 14.0%, 15.0%, 10.2%, 18.0%, 17.9%, and 17.3% higher compared with those in OSLDcont for 75, 80, 90, 95, 100, and 105 kVp, respectively. The dose accumulation and bleaching time did not significantly alter the sensitivity, regardless of the filling of deep traps for all radiation qualities. Both OSLDexp and OSLDcont exhibited good linearity, by showing coefficients determination (R2) > 0.99. The OSL sensitivities can be increased by filling of deep electron/hole traps in the energy ranges between 75 and 105 kVp, and they exhibited no significant variations according to the bleaching time.