TL Glow Curve and Kinetic Parameters of Amethyst Exposed to High Dose of Gamma Radiation

Abstract

To know if a certain thermoluminescent (TL) peak is suitable for dosimetry, it is important to determine its lifetime. The mean lifetime may be calculated using the geometrical factor of the TL glow curve to determine the kinetic parameters such as activation energy and frequency factor of electrons in traps. The kinetic parameters to the peak at 202 ºC of a natural amethyst from Brazil, were obtained by using the peak shape methods applied on the TL glow curve, before and after deconvolution procedure. The peak at 202 °C was chosen because lies between 180 °C and 400 °C, a region of interest for dosimetric applications. Before deconvolution, the calculated lifetime for the peak at 202 °C was relatively short close to 35 days. However, the calculated lifetime after deconvolution was around 312 days, suggesting a longer lifetime. The results showed the importance of deconvolution for the calculation of the kinetic parameters of the TL peak of amethyst exposed to high dose of gamma radiation.