Thermally stimulated luminescence of NaF and NaF:Dy phosphors exposed to beta particle irradiation

The objective of radiation dosimetry is the measurement of radiation dose, and the most successful dosimetric technique is thermoluminescent dosimetry, based on the phenomenon of thermoluminescence (Tl), in which phosphors are used that store a fraction of the energy of incident ionizing radiation and subsequently release it in the form of light upon receiving thermal stimulation. In the present work, the synthesis and thermoluminescent characterization of NaF and NaF:Dy phosphors exposed to beta radiation are reported. The brightness curves show emission from 94 °C to 350 °C, with the absolute maximum around 200 °C, a temperature considered suitable for thermoluminescent dosimetry. A notable sensitization effect was observed in the irradiation-reading cycles for the NaF samples, which decreases by reducing the particle size of the NaF during the synthesis of the material and with the incorporation of the dopant (Dy), considerably improving the reusability of the NaF. From the experimental evidence presented, it is concluded that NaF is a promising phosphor for the development of new thermoluminescent dosimeters. (author)