Blue- and infrared-light stimulated luminescence of microcline and the effect of optical bleaching on its thermoluminescence

Abstract

We report blue-light stimulated luminescence (BSL) and infrared-light stimulated luminescence (IRSL) of microcline along with the effect of optical bleaching on its thermoluminescence (TL) glow peaks. Analysis of BSL and IRSL decay curves of the sample shows that the decay curves are composed of a fast component C1 and a slow component C2. The decay time of these components depends somewhat on dose. For components C1 and C2 of BSL, the decay times are consistent at (3.47 ± 0.31) s and (27.19 ± 1.39) s respectively for doses within 1–10 Gy but become faster for dose beyond 10 Gy. On the other hand, the decay times of the component C1 of IRSL for any doses between 1 Gy and 100 Gy are consistent at (8.61 ± 2.10) s and that of C2 at (44.97 ± 6.43) s. The difference in decay times between BSL and IRSL emission are attributed to nature of transitions involved in BSL and IRSL emissions. Analysis of BSL and IRSL dose responses shows that the BSL decay curves as well as its components C1 and C2, each produce a linear response within 1 Gy–10 Gy and increases exponential thereafter. In comparison, the dose response of the IRSL as well as that of its components are linear between 1 Gy and 100 Gy. Studies comparing the effect of optical bleaching on the TL intensity suggests that use of infrared light for this purpose can produce a relatively longer linear dose response than that following bleaching by blue light.