The Trigger System of the H.E.S.S. Telescope Array
  H.E.S.S. -- The High Energy Stereoscopic System-- is a new system of large atmospheric Cherenkov telescopes for GeV/TeV Gamma-ray astronomy. This paper describes the trigger system of H.E.S.S. with emphasis on the multi-telescope array level trigger. The system trigger requires the simultaneous detection of air-showers by several telescopes at the hardware level. This requirement allows a suppression of background events which in turn leads to a lower system energy threshold for the detection of Gamma-rays. The implementation of the H.E.S.S. trigger system is presented along with data taken to characterise its performance. 
S. Funk, G. Hermann, J. Hinton, D. Berge, K. Bernloehr, W. Hofmann, P.   Nayman, F. Toussenel, P. Vincent