Thermoluminescent Dosimeters

Thermoluminescence Dating

Thermoluminescent dosimetry is developed to measure the degree of radiation to which a person is exposed . The device stores the radiant energy and later releases it in the form of visible or , in some cases ultraviolet light . Thermoluminescent dosimeter consists of a crystalline material which changes its color depending on the type of ionizing radiation . During the measurement the material is heated and the thermoluminescence , as weak signal of light , is produced . That thermoluminescence is proportional to the produced dose of radiation (Atiken , 1985 ) Imperfections in natural crystalline materials lead

to dips in electronic potential and , where there is an electron trap , free electrons are either attracted or trapped . In such a way , a flux of ionizing radiation is released both from natural radioactivity and cosmic radiation . Therefore , the amount of produced light equals the amount of radiation dose (Horowitz , 1984

Thermoluminescence signal is zero at the point , where the material is heated or exposed to sunlight because pre-existing trapped electrons are removed . Ionizing radiation cases trapped electrons to accumulate and in laboratory before measuring radiation dose it is necessary to determine the time that has passed since zeroing event (Avvakumova , et al , 1990 The rate of radiation dose is estimated by measuring the alpha radioactivity of the sample material . In particular , it is necessary to estimate the uranium and potassium content . Gamma radiation of material measured is also calculated from potassium content and alpha productivity . When all the components of the radiation d estimated then radiation dose...