Time-resolved luminescence of low sensitivity quartz from crystalline rocks M.L. Chithambo, F. Preusser, K. Ramseyer and F.O. Ogundare Abstract Time-resolved luminescence spectra of low sensitivity natural quartz from crystalline rocks are presented. The luminescence was pulse-stimulated at width using 470 nm blue light from quartz separated from plutonic, metamorphic, volcanic and hydrothermal samples. Measurements were made at 20 °C. All samples show evidence of a short lifetime component less than long although in several cases too weak in intensity to be evaluated accurately. On the other hand, the value of the principal lifetime component varies considerably being about in metamorphic quartz, in plutonic quartz, and in one example of hydrothermal quartz. The results illustrate a new feature of luminescence from quartz for which lifetimes less than or greater than have never been reported at room temperature before. It is argued that the thermal provenance of the quartz and so the annealing it will have experienced influences the size of the observed lifetime. In particular, the results are explained in terms of a model consisting of three luminescence centers with the dominant lifetime linked to preferential recombination at one center depending on the thermal history of the sample and hence the hole concentration of the center. 1. Introduction Optically stimulated luminescence (OSL) from quartz, an ubiquitous natural dosimeter, has normally been measured using continuous optical stimulation. In this method, the luminescence is recorded simultaneously with stimulation light of essentially constant intensity. The luminescence and scattered stimulation light are discriminated by judicious use of band pass filters to transmit the luminescence and transmission filters to attenuate the intensity of the scattered stimulation light (Bøtter-Jensen, 1997 and Galloway et al., 1997 ). The intensity of the emitted luminescence decreases in time approximately exponentially to produce a decay curve. Typical decay curves can be deconvoluted by non-linear regression into three principal components; the fast, medium and slow component, respectively (Bailey et al., 1997 , Chithambo and Galloway, 2001a and Smith and Rhodes, 1994 ). However, Bulur et al. (2000) , using linearly ramped stimulation light, reported examples consisting of more than three components owing to the presence of multiple slow components. Further application of linearly modulated stimulation of luminescence showed that physical characteristics of each of the components, such as the photoionization cross-section, are not necessarily similar (Kuhns et al., 2000 ). Working along similar lines of investigation,