Afterglow characteristics of an X-ray irradiated imaging plate

The effect of time and temperature dependence of the afterglow intensity are measured for several kinds of commercial imaging plates composed of BaFBr0.85I0.15:Eu2+ and BaFBr:Eu2+. Emission spectra of the afterglow reveal a single band with a maximum around 400 nm. It is found that the afterglow intensity is usually increased with increasing temperature. The time dependence of the afterglow is analysed using a recombination model particularly in relation to the temperature and the distance between electrons and holes. It is shown that theoretical curves with three reasonable parameters are in good agreement with the experimental data. A relation between afterglow and fading is also discussed using the proposed recombination model. (author)