Evaluation of the first Silicon Photomultiplier matrices for a small animal PET scanner

A high resolution small animal PET scanner that employs Silicon Photomultiplier (SiPM) matrices as photodetectors is under development at the University of Pisa. The first SiPM matrices fabricated by the Center for Scientific and Technological Research, FBK-irst, Trento, Italy, are being evaluated for this purpose. The devices are composed of 16 (4×4) pixel elements of 1 mm × 1 mm in a common substrate. The first tests have been carried out employing the ASIC MAROC2 for the readout. Energy and timing resolution, and position determination tests have been carried out coupling both pixellated and continuous LYSO scintillator crystals to the matrix, and the results have been compared with the ones obtained for single SiPMs.