Optical and scintillation properties of large LuAlO3 : Ce3+ crystals

The LuAlO3 : Ce3+ system has been shown to be a promising scintillator for medical imaging devices. Recently, efforts were focused on the improvement of its scintillating properties. Several large crystals with various cerium concentrations were grown. Absorption and excitation spectra were measured in a range extending from the visible to the vacuum ultraviolet (VUV). Emission spectra, fluorescence decay times and light yields, both under γ-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. (author)