Progress in the development of LuAlO/sub 3/-based scintillators

LuAP:Ce and mixed LuYAP:Ce crystals are the promoted scintillation materials for positron emission tomography. These scintillators are presently being studied in three directions: 1) growth of large crystals with stable properties; 2) establishment of relationships between the composition of LuYAP:Ce crystals and the scintillation properties; and 3) scintillation mechanisms in lutetium compounds. We performed the first bunch of 16 LuYAP:Ce crystals with size for the detector module (2/spl times/2/spl times/10 mm/sup 3/). The crystals show good correlation among growth parameters, light yield, and transmission spectra. To clarify the scintillation mechanism in LuAP:Ce and LuYAP:Ce crystals, measurements of absorption, emission, and excitation spectra of thermoluminescence and scintillation decay curves have been performed.