Floodmap measurement of a pixellated gamma scintillation detector module using fully integrated readout

Scintillation crystal arrays with narrow pitch are a very powerful tool to develop high spatial resolution γ ray detectors, e.g. as they are used in preclinical PET applications. In order to keep the number of detector channels as low as possible, light guides are used. As a result, the light from one crystal is spread over a number of larger detector elements, which allow a reconstruction of the position of the scintillation process by analyzing the energy contribution of several adjacent channels. In this case a proper measurement of the light distribution is very demanding, because missing channels with low amount of optical photons could significantly influence the position estimation. In this paper we present a fully integrated system comprising the scintillator crystals, a light spreader, SiPM photon detectors, and ASIC readout electronics that include a neighbor logic to improve position estimation. We show first flood histogram measurement which demonstrates clear identification of most of the crystals.