Thermoluminescence of NaF and NaF:Tm phosphors exposed to beta particle irradiation

This work reports the synthesis and beta particle excited thermoluminescence (TL) characteristics of NaF and NaF:Tm phosphors synthesized via wet precipitation. The samples were subjected to thermal annealing at 750 °C for 5, 10, and 24 h in an air atmosphere. A sensitization effect is observed in repeated irradiation-TL readout cycles. The sensitization effect significantly decreases with increasing duration of thermal treatments and with decreasing irradiation dose. Furthermore, doping with Tm simplifies the shape of the glow curves in the region of maximum thermoluminescent intensity, located between 200 and 250 °C, a temperature range considered suitable for thermoluminescent dosimetry. The integrated TL is a linear function of the irradiation dose for the tested dose range (0.05 Gy-1.78 Gy). NaF is presented as a promising alternative to LiF for developing highly sensitive TL dosimeters, and it is concluded that NaF is a promising phosphor material, warranting further research into its dosimetric capabilities.