Scintillation properties of mixed LuYAP crystals in view of their use in a small animal PET scanner in phoswich configuration

Phoswich detectors are currently being considered by a number of investigators for depth-of-interaction (DOI) measurements in PET. In this work, the scintillation properties of several batches of Lu_0.7Y_0.3AlO₃ crystals doped with cerium were studied. The scintillators exhibited an excellent energy resolution and a light output comparable to BGO. The light pulse shape showed two components with 25 ns and around 250 ns. The light yield nonproportionality on photon energy was studied as well as the intrinsic energy resolution. Absorption, excitation and emission spectra were measured in a range extending from visible to ultraviolet. First results in the combination of these LuYAP crystals with LSO:Ce crystals in phoswich geometry for the final PET scanner are presented. The experimental results show that the new DOI detector is applicable for high-resolution PET systems.