Thermoluminescence kinetics in materials exposed to the low doses applicable to dating and dosimetry

Thermoluminescence (TL) kinetics have been investigated for low dose situations applicable to dating, dosimetry, and recent geological deposits. Studied were the general one-trap kinetic equation, which reduces to the well known 1st and 2nd order kinetic equations when various assumptions apply, and the interactive kinetic equations, which describe TL in materials exhibiting more than one glow peak. In materials with one glow peak the peak area varies linearly with dose; however, peak height is not linear with dose unless the TL obeys 1st order kinetics at all doses. In materials with two or more glow peaks neither peak height nor peak area varies linearly with dose, except in special situations. In fact, many peak height vs. dose curves will be supralinear with the initial low-slope region occurring at relatively low doses. These considerations indicate: (1) dating and dosimetry techniques based on assumed linear peak height vs. dose curves will usually underestimate the accumulated dose; (2) dating techniques can be improved and/or made more reliable by determining the TL kinetics of the glow peaks measured. (author)