Abstract
The phenomenon of thermoluminescence (TL) cannot yet be said to be completely understood, and cases of anomalous results from TL dating programmes are not infrequent, although explanations are rarely given. It is therefore useful to put TL dating into a firmer physical framework in which all relevant phenomena can be adequately described, whence the best action can be taken to avoid spurious results. However, TL dating embraces many varied aspects of physics, and a solution to all the problems is not a simple task. This thesis is intended to be an experimental study of some of the main physical techniques in thermoluminescence dating. Following a brief review of the whole field, selected areas presented here have been investigated in more detail. A new TL reader has been implemented with novel design features, including microprocessor controlled heating cycles, a switch-mode power supply direct current heating, all based on a modular concept to facilitate future improvements in the hardware. The use of a microprocessor as the heating controller should enable further development (eg. data collection and processing) to be a straightforward task. Non-linear heating profiles can be generated for glow curve analysis and for providing pre-heat zones. The radioisotope content of ceramics and soils is important in TL dating, and a comparison of commonly used radio assay techniques has been made with the aim of assigning a minimum detectable activity to each technique for a given required accuracy. The analytical methods have been applied to various ceramic samples, and the derived dose rates within the shards are calculated and presented for comparison. Some theoretical aspects of TL described in this thesis include a computer model to simulate common TL phenomena, which is used to investigate the effects of varying the model parameters. A complete solution of the equations determining glow curve shapes produced by hyperbolic heating profiles is presented, with techniques for extracting the mathematical constants describing the model, from them. A brief intercomparison of five quartz samples of differing origins is presented with a trace element analysis of the samples to determine whether there exists a correlation between trace element concentration and the magnitude of the TL properties.