The NA62 LAV front-end electronics and the L0 trigger generating firmware

The aim of the NA62 experiment is to measure the branching ratio of the decay K + ! p + n ̄ n to within about 10%. The large-angle photon vetoes (LAVs) must detect particles with better than 1 ns time resolution and 10% energy resolution over a very large energy range in order to reject the dominant background: photons coming from p + p 0 decays. A low threshold, large dynamic range, time-over-threshold based solution has been developed for the LAV front end electronics (LAV-FEE). Our custom 32 channel 9U board uses a pair of low threshold discriminators for each channel to produce LVDS logic signals. The achieved time resolution obtained in laboratory, coupled to a readout board based on the HPTDC chip developed at CERN, is 100 ps. For LAV-FEE, a FPGA-based level-0 trigger providing slewing-corrected trigger time with similar precision has also been developed.