Thermoluminescence

Some mineral substances such as fluorite store energy when exposed to ultraviolet or other ionising radiation. This energy is released in the form of light when the mineral is heated; the phenomenon is distinct from that of black body radiation.

The amount of light given off is proportional to the dose of radiation received. In thermoluminescence dating, this can be used to date buried objects that have been heated in the past (eg pottery) since the dose received from radioactive elements in the soil, cosmic rays etc is proportional to age. This phenomenon has been used for Thermoluminescent dosimeters, to measure the radiation dose received by a chip of suitable material that is carried around by a person or placed with an object.

Thermoluminescence is a common [geochronology] tool for dating pottery or other 'fired' archeological materials, as heat empties or resets the thermoluminescent signature of the material (Figure 1). Subsequent 'recharging' of this material from ambient radiation can then be empirically dated by the simple equation:

Age = (subsequently accumulated dose of ambient radiation)/(dose accumulated per year)

This technique was modified for use as a "passive sand migration analysis tool" by [http://www.jcronline.org/perlserv/?request=get-abstract&doi=10.2112%2F04-0406.1 Keizars, "et al.", 2008] (Figure 2). This study shows direct consequences resulting from the improper replenishment of starving beaches using fine sands. Beach nourishment is a problem worldwide and receives large amounts of attention due to the millions of dollars spent yearly in order to keep beaches beautified for tourists (e.g. [http://www.signonsandiego.com/news/science/20061225-0031-waikikisand.html Waikiki, Hawaii)] . Sands with sizes 90-150 μm (very fine sand) were found to migrate from the swash zone 67% faster than sand grains of 150-212 μm (fine sand; Figure 3). Furthermore, the [http://www.jcronline.org/perlserv/?request=get-abstract&doi=10.2112%2F04-0406.1 Keizars, "et al.", 2008] technique was shown to provide a "passive" method of policing sand replenishment and a "passive" method of observing riverine or other sand inputs along shorelines (Figure 4).

Literature

* "Thermoluminescence dating" by M J Aitken, ISBN 0-12-046381-4
* [http://www.sciam.com/article.cfm?articleID=0006AA6A-9D17-1C75-9B81809EC588EF21&pageNumber=2&catID=4 The Dating Game] Scientific American June 11, 2001 page 2
* Keizars, K.Z. 2003. NRTL as a method of analysis of sand transport along the coast of the St. Joseph Peninsula, Florida. GAC/MAC 2003. Presentation: Brock University, St. Catherines, Ontario, Canada.
* [http://www.jcronline.org/perlserv/?request=get-abstract&doi=10.2112%2F04-0406.1 Ķeizars, Z.] , Forrest, B., Rink, W.J. 2008. Natural Residual Thermoluminescence as a Method of Analysis of Sand Transport along the Coast of the St. Joseph Peninsula, Florida. Journal of Coastal Research, 24: 500-507.
*Keizars, Z. 2008b. NRTL trends observed in the sands of St. Joseph Peninsula, Florida. Queen's University. Presentation: Queen's University, Kingston, Ontario, Canada.


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Thermoluminescence — de fluorite. La thermoluminescence est un phénomène physique lié à la capacité de certains cristaux d accumuler l énergie cédée par les rayonnements ionisants issus de la radioactivité et de restituer cette énergie sous forme de lumière lorsqu… …   Wikipédia en Français

  • thermoluminescence — [ tɛrmolyminesɑ̃s ] n. f. • 1897; de thermo et luminescence ♦ Sc. Luminescence provoquée par l élévation de la température d une substance préalablement excitée par irradiation. Datation par thermoluminescence (ou datation TL) d objets… …   Encyclopédie Universelle

  • Thermoluminescence — Ther mo*lu mi*nes cence, n. (Physics) Luminescence exhibited by a substance on being moderately heated. It is shown esp. by certain substances that have been exposed to the action of light or to X rays. {Ther mo*lu mi*nes cent}, a. [Webster 1913… …   The Collaborative International Dictionary of English

  • thermoluminescence — [thʉr΄mōlo͞o΄mə nes′əns] n. [ THERMO + LUMINESCENCE] the release in the form of light of stored energy from a substance when it is heated thermoluminescent adj …   English World dictionary

  • thermoluminescence — noun Etymology: International Scientific Vocabulary Date: 1897 1. phosphorescence developed in a previously excited substance upon gentle heating 2. the determination of the age of old material (as pottery) by the amount of thermoluminescence it… …   New Collegiate Dictionary

  • thermoluminescence — thermoluminescent, adj. /therr moh looh meuh nes euhns/, n. Physics. phosphorescence produced by the heating of a substance. [1895 1900; THERMO + LUMINESCENCE] * * * Emission of light from certain heated substances as a result of previous… …   Universalium

  • thermoluminescence — termoliuminescencija statusas T sritis Standartizacija ir metrologija apibrėžtis Šviesos ar kietąja rentgeno spinduliuote sužadinto šildomo kristalo švytėjimas. atitikmenys: angl. thermoluminescence vok. Thermolumineszenz, f rus.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • thermoluminescence — šiluminė liuminescencija statusas T sritis fizika atitikmenys: angl. thermoluminescence vok. Thermolumineszenz, f rus. термолюминесценция, f pranc. thermoluminescence, f …   Fizikos terminų žodynas

  • thermoluminescence — termoliuminescencija statusas T sritis chemija apibrėžtis Rentgeno spinduliuote sužadinto kristalo švytėjimas jį pašildžius. atitikmenys: angl. thermoluminescence rus. термолюминесценция …   Chemijos terminų aiškinamasis žodynas

  • thermoluminescence — noun The release of previously absorbed radiation upon being heated. See Also: thermoluminescent …   Wiktionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.