(b) A glow-curve from incandescence resulting from the second heating of the sample to a high temperature. Bleaching rates of quartz (q) and feldspar (f) stimulated using TL and OSL (green light) conducted by Godfrey-Smith et al. For the OSL, both quartz and feldspar used a green laser and a detection window of 380 nm which is violet to near-UV . Examples of TL (a, b) and OSL (c, d) emission spectra (adapted with permission from Ref. For TL spectra, the sharp rise in emissions beyond 650 nm is largely from incandescence (rather than from electrons evicted from traps). Main emission wavelengths for quartz and feldspars used in luminescence dating as well as wavelengths employed for stimulation.It is important to note that incandescence is also realized above 400°C during the first heating (redrawn from Ref. Sensitivity ranges for some detectors are also shown. Main methods employed in determining the equivalent dose.In earth sciences and archaeological applications, the dielectric materials are usually minerals such as feldspar and quartz.The materials are also sometimes referred to as dosimeters .Measuring the amount of energy released in conjunction with a determination of the rate at which the energy was accumulated allows an age to be calculated, indicating time that has elapsed since the storage of energy began.Luminescence methods can generally be used to date materials that range in age from a few decades to about 100,000 years.However, ages of up to several hundred thousands of years have been reported in some studies .
When the minerals are stimulated, they release the stored energy in the form of light, from which the term luminescence is derived.Physics » "Luminescence - An Outlook on the Phenomena and their Applications", book edited by Jagannathan Thirumalai, ISBN 978-9-5, Print ISBN 978-9-8, Published: November 10, 2016 under CC BY 3.0 license. Both electrons and holes diffuse within the lattice. An energy level diagram that illustrates how ionizing radiation creates luminescence centers in crystal lattices (redrawn from Ref. (a) Following irradiation, electrons are expelled from their original sites leaving holes behind.Stimulation of energy release by heating is referred to as TL.
When light is used, on the other hand, the technique is described as OSL.
Growth curves are unique to each sample being analyzed such that new measurements have to be made and a new curve constructed for every sample being dated. Examples of growth curves for quartz taken to saturation (redrawn after ).