The trigger system for K0→2π0 decays of the NA48 experiment at CERN

A fully pipelined 40 MHz “dead-time-free” trigger system for neutral K 0 decays for the NA48 experiment 2 at CERN is described. The NA48 experiment studies CP-violation using the high intensity beam of the CERN SPS accelerator. The trigger system sums, digitises, filters and processes signals from 13 340 channels of the liquid krypton electro-magnetic calorimeter. In 1996 the calorimeter and part of the trigger electronics were installed and tested. In 1997 the system was completed and prepared to be used in the first NA48 physics data taking period.