Photon Imaging of Thermoluminescence

Thermoluminescence radiation dosimetry of geological or archaeological materials, for age determinations, is susceptible to errors caused by non-uniformity of the samples. Even in synthetic dosemeters there can be problems of non-uniformity, or of cross contamination between samples. In order to observe the uniformity of the dosimetry from the samples a Photek photon imaging camera has been installed on a spectrally resolved thermoluminescence system. Data obtained in this way clearly relate problem samples to zones of high intensity emission, even when there are no obvious anomalies in the emission spectra. Additionally, the pattern and uniformity of radioluminescence can differ from that of thermoluminescence. Non-uniformity from multi-mineral mixtures can be correlated with emission spectra in those cases where there are clear differences between the spectra of the components. The imaging camera performance is comparable with the sensitivity of normal TL detection and clear dynamic images are obtained during the TL from borates or sulphates following radiation doses of