The study of small and large size LuAlO/sub 3/:Ce/sup 3+/

The LuAlO/sub 3/:Ce/sup 3+/ system was shown to be a promising scintillator for medical imaging devices. Recently, efforts were focused on the improvement of its scintillating properties. Several large size crystals with various cerium concentrations were grown. Emission spectra, fluorescence decay times and light yields, both under /spl gamma/-ray and X-ray excitation, were measured under various experimental conditions. A reabsorption process is shown to take place in this material. This process is responsible for the observed decrease of the light yield when increasing the size of the sample.