Effect of high gamma doses on the sensitization of natural quartz used for thermoluminescence dosimetry

Abstract

This article reports the sensitization of the glow peak at 300 °C in crystalline quartz by using high doses of gamma radiation. Five lots of samples were prepared from single crystals extracted from different geological occurrences in Brazil. The specimens were submitted to high doses of 60Co radiation starting at 25 kGy and going up to a cumulative dose of 350 kGy. After each high dose application, the samples were submitted to a thermal treatment and then irradiated with gamma radiation doses ranging from 2 to 20 mGy. The thermoluminescence (TL) response for each quartz lot was then determined. The results showed a remarkable increase in the TL peak at 300 °C for samples from three of the lots after the administration of a dose of 25 kGy. The pre-dose necessary to obtain the maximum in sensitization was dependent on the origin of the quartz samples and on their Al, Li and OH impurity contents.