The trigger system of the Pierre Auger Surface Detector: operation, efficiency and stability

D. ALLARD; E. ARMENGAUD; I. ALLEKOTTE; P. ALLISON; J. AUBLIN; M. AVE; P. BAULEO; J. BEATTY; T. BEAU; X. BERTOU; P. BILLOIR; C. BONIFAZI; A. CHOU; J. CHYE; S. DAGORET-CAMPAGNE; A. DOROFEEV; P.L. GHIA; M. GOMEZ BERISSO; A. GORGI; J.C. HAMILTON; J. HARTON; R. KNAPIK; C. LACHAUD; I. LHENRY-YVON; A. LETESSIER-SELVON; J. MATTHEWS; C. MEDINA; R. MEYHANDAN; G. NAVARRA; D. NITZ; E. PARIZOT; B. REVENU; Z. SZADKOWSKI; T. YAMAMOTO

Pune, India

Conferencia; 29th International Cosmic Ray Conference; 2005

The trigger system of the Surface Detector (SD) of the Pierre Auger Observatory is described, from the identification of candidate showers (E>1 EeV) at the level of a single station, among a huge background (mainly single muons), up to the selection of real events and the rejection of random coincidences at a higher central trigger level (including the reconstruction accuracy). Efficiency of a single station trigger is evaluated using real data , and the high performance of event selection hierarchy will be demonstrated.