The ARGO-YBJ ground-based detector allows to investigate many issues in gamma-ray astronomy and cosmic ray physics spanning a large energy range by means of its ability to operate down to a few hundreds of GeV up to a few PeV. The apparatus consists of a single layer of about 2000 Resistive Plate Chambers (RPCs) for a total instrumented area of ~6700 m2. The whole detector has been fully equiped with final front-end, trigger and DAQ electronics and is in data taking since last February. The detection of small size showers is one of main tasks of the ARGO-YBJ experiment. The maximum trigger rate due to cosmic rays that the system can acquire is 15 KHz with a data transfer rate of about 16 MB/s. In this paper the design and performance of the trigger system will be described.

ARGO-YBJ collaboration

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 5 (HE part 2), pages 1065-1068