The effects of annealing and irradiation on the sensitivity and superlinearity properties of the 110oC thermoluminescence peak of quartz

Quartz samples which undergo heating and irradiation treatments exhibit changes in their sensitivity to irradiation, as well as in their TL dose response. These changes of thermoluminescence (TL) sensitivity and superlinearity of the 110 deg. C TL peak of quartz have been the subject of several experimental and theoretical studies, because they form the basis of the predose technique for dating ceramics and for accident dosimetry. In an effort to separate experimentally the effects of irradiation and annealing on the predose effect, three quartz samples of different origin were prepared under three different conditions: unannealed samples, samples annealed at 500 deg. C, and samples annealed at 900 deg. C. Complete TL versus dose and sensitivity S versus predose curves were obtained for the dose range of 0.1<D<400Gy. Additional complete sets of data were obtained for samples that underwent a combined predose irradiation and a heat treatment to 500 deg. C. Although the TL versus dose curves and the sensitivity versus predose data showed very different behaviors, preannealing the samples at 900 deg. C removed the observed differences that are due to the thermal or irradiation history of the quartz samples. The experimental data is consistent with the assumption that high-temperature anneals and/or high dose irradiation of the samples reduces the concentration of available competitor sites. The concentration of these competitor sites, as described by the Zimmerman model of quartz, is identified as the most important factor in causing the observed differences in predose behavior between quartz samples of different origin. Strong evidence in support of this competitor theory is provided by the estimated equivalent doses (EDs) for the three quartz samples