Fading study and readout optimization for routinely use of LiF:Mg,Ti thermoluminescent detectors for personal dosimetry

Abstract

LiF:Mg,Ti thermoluminescent dosimeters (TLDs) are frequently used for personal dosimetry by individual monitoring services (IMS) all over the world. This study focused on the investigation and accurate description of thermoluminescent signal fading in these dosimeters. The routine readout procedure was performed with the controlled heating of the detector elements according to defined time-temperature profiles (TTPs). The output of this procedure was a temperature dependent light signal, called glow curve. Additionally, the readout optimization was achieved with the simulation and validation of glow curves with different fast readout TTPs. The TLDs were annealed, irradiated and read out with different storing times at an ambient temperature of 25 °C. Six batches of each 100 TLDs were irradiated and read out with different TTPs and compared afterwards. A fading study with several Harshaw TLD-100 dosimeters was performed, in which the results were responses to describe the pre-irradiation fading and the post-irradiation fading with mathematical functions that give a correction factor for the dose calculation.