First evaluations of the neighbor logic of the digital SiPM tile

For a high resolution PET/MRI insert, we are using pixelated scintillator arrays with 1 mm pitch in combination with digital SiPM arrays. The pitch of the digital SiPM arrays is 4 mm. Therefore, a light-sharing technique is used to identify individual crystals. Information from several sensors, a cluster, is needed to identify the crystal in which a gamma photon has been converted to scintillation photons. We present first evaluations of the neighbor logic (NL) of the PDPe DLS 3200-22 dSiPM. The NL allows the use of strict trigger validation criteria while delivering the complete light distribution on the sensor tile. Measurements are performed at ~10°C sensor temperature. We compare the measurement with enabled NL to a standard triggering scheme which needs to use low trigger validation thresholds in order to achieve the same performance. Positioning of clusters is performed using a center-of-gravity algorithm. We show that the NL trigger scheme allows to achieve a better energy resolution and improved crystal identification. Furthermore, we show that the NL allows to recover more clusters containing light distributions with less missing relevant information while reducing the noise level in the data by more than one order of magnitude.