PCDA — A massively parallel, scalable, precise, FPGA-based coincidence detector array

In Positron Emission Tomography (PET) and Quantum Optics, the quality of the reconstructed images is directly proportional to the quality of the employed coincidence detectors, which provide important timing information about the location of the emitted nuclear particles. This paper proposes a new circuitry, called precise coincidence detector (PCD). It consists of two RS latches, is of low complexity, and fully synthesizable in FPGAs. A first, non-optimized prototype on a standard Cyclone IV FPGA achieves a coincidence window smaller than 100 ps, which is more than ten times better than reported elesewhere. Because of its very low complexity, a standard FPGA can host tens of thousands of PCD elements, which can support the construction of high-precision, cost-effective tomographs.