Single level isothermal TL-decay (with energy level distribution and retrapping)

A simple theoretical model is developed for thermoluminescent isothermal decay of a single level having an activation energy distribution ρ(E) with retrapping present during the annealing process. The model is solvable for the thermoluminescent-emission from a level with a Gaussian distribution for ρ(E). This solution is given in an approximate analytic closed form to facilitate the examination of the role played by the various controlling parameters of the process. It was found very valuable to also treat the case of linearly increasing temperature annealing (i.e. the standardly obtained glow curve) with the same model. The analytic treatment of this process is mathematically more complicated and the solution is only attempted for the initial rise region of the thermoluminescence (TL) as temperature increases. Finally, the theoretical analysis that is developed is applied to preliminary experimental results obtained for the TL emission from TLD-400 ribbon. The ribbon form of this material appears to exhibit a single glow peak in the temperature range 300 < T (K) < 800. These results are very satisfactory and lead to acceptable physical parameters. (author)