The electronic system for a TOF PET prostate probe

In the framework of TOPEM (TOf PEt Mri) R&D program funded by Istituto Nazionale di Fisica Nucleare (INFN, Italy) a readout system for a matrix of Silicon PhotoMultipliers (SiPM) has been developed. The overall project has been already presented elsewhere: here the main focus is on the readout system that is based on existing components, available in the physic research community. The electronic system completely handles a SiPM matrix made up to 128 pixels, measuring both timing and charge information for each hit pixel. Although the device has been designed as dedicated unit for the TOPEM internal detector, a coincidence logic has been implemented, permitting to interface an external detector and trigger the data acquisition, implementing a complete, small angle TOF-PET system. The data acquisition is based on Linux PC, interfaced to the controller board using USB 2.0, running up to 25 MByte/s. Moreover, the controller can handle a 2^nd SiPM matrix (or other sensor such as Position Sensitive PhotoMultiplier Tube - PSPMT) which can be used to build a more complicated detector (i.e. dual side scintillator readout for Depth Of Interaction measurement) or the external detector itself. The system is completely running and laboratory tests are ongoing.