A Modification of the Kinetic Equations Used for Describing the Thermoluminescence Phenomenon

Abstract

In the present work we discussed the validity of the traditional first-, second- and general-order kinetic equations used to describe the thermoluminescence (TL) phenomenon. These equations were written in their present forms to explain the TL glow peaks at constant value of the heating rate. However, a widespread mistake was found when one uses these equations to explain the TL at different heating rates. This mistake is a result of unreal definition of the rate of change of trapped carriers as a function of temperature. A modification of the above-mentioned equations has been considered during this work to define correctly the TL phenomenon. As a result of this modification some characteristics of the TL glow peaks, namely, the TL intensity and the total integral will be changed. Following to the present work, an emendation of Chen-Winer method used to determine the activation energy of TL glow peak was considered during this work. Also, a modification of the equation used to determine the relative value of initial concentration of the trapped carriers was considered during this work.

Isothermal annealing of a 620nm optical absorption band in Brazilian topaz crystals

“…Assuming that a heating manner in an interval of time between one point (t j À 1 ) and the following point (t j ) in Fig. 1 is linear, a TL glow curve can be given by a sum of TL intensities over M intervals of time [33][34][35][36]. The mathematical expression of the TL glow curve for a single activation energy and first-order kinetics, I(t), is given by:…”