Radiation hardness of CsBr:Eu2+

In this study,results on the radiation damage of the storage phosphor CsBr:Eu2+ are presented. It is shown that a high X-ray dose causes a significant deterioration of the photostimulated luminescence accompanied by a degradation of the UV-excited Eu2+ fluorescence. Since no related dose-dependent increase of Eu3+ luminescence is observed, the decrease of Eu2+ fluorescence is attributed to an agglomeration of Eu2+ leading to luminescence quenching. The correlated diffusivity of Eu2+ ions is ascribed to the presence of aggregated F-centres such as MEu-centres observed by means of absorption spectroscopy.