The KFA TierPET: performance characteristics and measurements

We will present first results of the KFA Tier-PET, a positron emission tomograph with flexible geometry dedicated to in vivo studies of small animals. The flexible geometry allows us to change between measurements with high spatial resolution and measurements with increased sensitivity at the cost of resolution. The detectors consist of yttrium aluminium perovskit scintillator arrays which are glued together from 20/spl times/20 optically isolated crystals, coupled to position sensitive photomultiplier tubes. The fundamental design features concerning crystal dimensions and detector arrangement have been simulated. Based on this data, the definite dimensional outline of the crystals was determined. The YAP:Ce matrix in combination with a position sensitive photomultiplier leads to a detector block with a high spatial resolution. In first measurements a system sensitivity of 1.8 kcps//spl mu/Ci/ml has been evaluated for a detector-to-detector distance of 16 cm.