Definition of luminescence dating
These crystalline solids are constantly subjected to ionizing radiation from their environment, which causes some energized electrons to become trapped in defects in the molecular crystal structure.An input of energy, such as heat, is required to free these trapped electrons.Apparently there is no rhyme or reason in the distribution of luminescence throughout the plant or animal kingdom.The distinction between light and luminescence was first pointed out by Wiedemann .
I came to full awareness under the luminescence of the infirmary's overhead.
Since measured TL depends on time of exposition to natural radiations but also on the intensity of these radiations, to achieve a precise dating we need information about radioactivity of the area where the object was found.
During TL analysis, the sample is reheated by a controlled heating process, so the energy is released in the form of light (thermoluminescence) as the electrons escape.
Energy absorbed from ionising radiation (alpha, beta, gamma, cosmic rays) frees electrons to move through the crystal lattice and some are trapped at imperfections in the lattice.
Subsequent heating of the crystal can release some of these trapped electrons with an associated emission of light.A non-negligible part of materials which ceramic is usually made of (like quartz and feldspars) is thermoluminescent: those materials have trap states that can capture electrons after interaction with alfa, beta and gamma rays existing in nature.