Determination of trap parameters of 225ºC thermoluminescence glow peak of Natural Quartz

Abstract

To determine if a certain thermoluminescent peak is useful for dosimetry, it is important to know its lifetime. The lifetime is calculated using the trap parameters, energy of thermal activation Et and frequency factor s. The trap parameters of the peak 225ºC of quartz samples were obtained using different and complementary methods: peak shape, curve fitting and initial rise methods. That peak occur in temperature range  150ºC-250ºC that corresponds to the intermediate energy level, commonly used for retrospective dosimetry. Presenting relatively short lifetime, those peaks can be used for dose determination due to an accident, and it is expected that geological thermoluminescence signal should be weak compared to that grown from artificial radiation. The values of Et  and of s derived from the applied methods lead to the lifetime of 10 years when the material is submitted to 25oC of environment temperature.