Definition of luminescence dating

Posted by / 18-Aug-2020 10:25

Heating ceramic in a furnace resets TL accumulated by clay and other materials; from this time on, TL begins growing again as time passes; the more concentrated radioactivity where ceramic is, the quicker TL grows.

Thus by measuring TL we can date an object since the last time it was heated above 400°C.

(Chemistry) phosphorescence of certain materials or objects as a result of heating.

It is caused by pre-irradiation of the material inducing defects which are removed by the heat, the energy released appearing as light: used in archaeological dating dates, Bronson deduced five phases of occupation: phases II, III, and IV (spanning the first to seventh centuries) represent a proto-historic period, with fully-fledged state development occurring during the transition between phases IV and V, that is, the seventh century.

The accumulation of trapped electrons, and the gaps left behind in the spaces they vacated, occurs at a measurable rate proportional to the radiation received from a specimen’s immediate environment.

When a specimen is reheated, the trapped energy is released in the form of light (thermoluminescence) as the electrons escape.

Subsequent heating of the crystal can release some of these trapped electrons with an associated emission of light.

The amount of light produced is a specific and measurable phenomenon.

Material and objects of archaeological or historical interest that can be dated by thermoluminescence analysis are ceramics, brick, hearths, fire pits, kiln and smelter walls, heat treated flint or other heat-processed materials, the residues of industrial activity such as slag, incidentally fire-cracked rocks, and even originally unfired materials such adobe and daub if they had been heated in an accidental fire.

The wavelength of the emitted light is characteristic of the luminescent substance and not of the incident radiation.

Thermoluminescence (TL) is the process in which a mineral emits light while it is being heated: it is a stimulated emission process occurring when the thermally excited emission of light follows the previous absorption of energy from radiation.

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Apparently there is no rhyme or reason in the distribution of luminescence throughout the plant or animal kingdom.