Investigation of sensitivity loss and recovery method of CaF2:Mn (TLD-400) thermoluminescent dosimeter irradiated to high gamma dose

The change in the sensitivity of the CaF2:Mn (TLD-400) thermoluminescent dosimeter was studied under high-dose exposure. First, the sample was exposed to 1kGy and then the sensitivity loss was checked by standard annealing and irradiating to 1 Gy and compared with the control dosimeter received the same dose of 1 Gy. Also, by applying different heating processes, the appropriate heating time is obtained to recover the lost sensitivity. In addition, the kinetic parameters of the TLD-400 TL dosimeter were determined before and after receiving a high dose, at each stage of the heating process, and recovery of sensitivity and modifications were identified. The kinetic parameters are obtained by fitting experimental data with a theoretical curve obtained from the general order model using a computer program.