Relationship between thermoluminescence and thermally stimulated exoelectron emission of BeO thin film dosemeters

BeO thin films have been suggested as TSEE dosemeters. Apart from TSEE they also show thermoluminescence. Their TL properties are very similar to those of BeO ceramics with respect to temperature position of the maxima, spectral distribution of the emitted light, optical fading and mass specific TL sensitivity. For both TSEE and TL optical fading is more pronounced at the low temperature glow peaks. However, TSEE and TL originate from different centres whose relationship to the corresponding centres in ceramic BeO is discussed. Previously emptied emission centres are refilled by phototransfer during UV irradiation. Thus dose reassessment is feasible. The TSEE signal can still be re-established after a dose readout heating cycle up to 6000C, whereas TL is annealed completely already below 3000C. (author)