Factors Influencing the Minimum Detectable Dose for Thermoluminescent Dosimeters.

Abstract

This study examines the range of methodologies used to determine the minimum detectable dose for LiF:Mg,Ti thermoluminescent dosimeters, emphasizing the importance of incorporating uncertainties when assessing variability in dosimeter response. Dosimeters serve various purposes, such as verifying delivered doses, personnel monitoring, environmental surveillance, and research. Each application has unique performance requirements: research may prioritize accuracy and sensitivity at low doses, while routine monitoring favors robustness and efficiency. Dosimetry goals must therefore balance precision, practicality, and resource constraints based on the specific context. This study focuses on four operational factors-dose calibrations, machine vs. oven annealing, heating rate optimization during readout, and glow curve analysis techniques-that shape the variability observed in dosimeter response. Six common methods for calculating the minimum detectable dose were identified from literature and explored in this study. The results demonstrate a wide range of minimum detectable dose values of 10 μGy to 104 μGy, which reflects the combined influence of both uncertainties and the choice of equation. Heating rate was found to have the most significant impact on variance, while annealing methods and analysis techniques had moderate effects, and calibration uncertainties showed smaller implications. Rather than striving solely for the lowest minimum detectable dose, this study features the importance of understanding how these factors influence the minimum detectable dose and applying this knowledge to achieve realistic and application-specific dosimetry goals.