Real-time FPGA design for the L0-trigger of the RICH detector of the NA62 experiment at CERN SPS

The NA62 experiment aims at measuring rare kaon decays, in order to precisely test the standard model. The RICH (Ring Imaging CHerenkov) detector of the experiment is instrumental in charged-particle identification and in measurement of their crossing time, with a resolution better than 100 ps. Here we describe the design of the Level-0 trigger system for the RICH, which provides a precise time reference by counting the input hit multiplicity within programmable fine-time windows. Since the design does not use spatial information and stands the maximum input rate of TDC-based NA62 systems, it can be deployed also in other subdetectors.