The new trigger/GPS module for the EEE project

Abstract

The Extreme Energy Events Project is an experiment devoted to the study of the Extensive Atmospheric Showers (EAS) which consists of a network of Multigap Resistive Plate Chambers (MRPCs) muon telescopes distributed over a very large area ∼ 3 t i m e s 1 0 5 k m 2 . It requires a precise time synchronization to correlate the information collected from each single detector. The data acquisition system of each telescope is equipped with a trigger unit and a GPS receiver to perform precision timing of events. The Global Positioning System (GPS) unit provides the one pulse per second signal (1PPS) which is used to create a timestamp in UTC time. A novel VME trigger unit for the EEE telescopes was developed, including an embedded GPS engine for timing application. The trigger/GPS unit is presented, including some preliminary measurements of its time resolution. • The VME trigger unit includes an engine GPS to create the timestamp in UTC time. • The absolute time of an event is built by adding both the TDCs and the GPS data. • GPS unit provides the one pulse per second signal (1PPS) to synchronize the TDCs. • The time resolution measured for the 1PPS is less then ∼ 5 ns.