The clock and control signal distribution system for the NA48 experiment

In the NA48 experiment at CERN, several detector subsystems located at distances of up to 200 m between each other produce data on a continuous basis and feed them into pipelines. Triggers are produced after variable delay times by two different systems for charged and for all-neutral kaon decays. To allow the retrieval of the corresponding data from the various subsystems and their merging into complex events by means of timestamps, a special, highly stable global clock distribution system has been developed. The design principles and the setup of the clock system are described and results for clock stability monitoring and automated correction of the signal transmission speed are reported.