Pure thermal sensitisation and pre-dose effect of OSL in both unfired and annealed quartz samples

Abstract

The sensitisation of quartz has attracted much attention since its thorough understanding is important in luminescence studies and dating applications. The present investigation examines the influence of pure thermal activation and predose treatments on the sensitisation of different components of linearly modulated optically stimulated luminescence (LM-OSL) measured at room temperature (RT) thereby eliminating undesired thermal quenching effects. Annealed and unfired quartz samples from Nigeria were used. The OSL measurements were carried out using an automated RISØTL/OSL reader (model-TL/OSL–DA–15). A new approach was adopted to match each of the resolved components of the RT-LM-OSL to respective thermoluminescence (TL) peaks that share the same electron trap and recombination centers. Pure thermal activation and pre-dose treatments respectively affect the sensitisation of all the components of the RT-LM-OSL in a similar manner as the one reported for the 110°C TL peak but without thermal quenching contributions. Component C4 in annealed samples that was identified to share the same electron trap and recombination centers with the 110°C TL peak was also proved appropriate for RT-LM-OSL, instead of the initial part of the continuous wave (CW) OSL signal, thus the methods can serve as complementary dating methods.