A large air shower array to search for astrophysical sources emitting [gamma]-rays with energies >=1014 eV

Abstract

We describe the technical details and the performance of a large array which detects both the electron and muon components in extensive air showers with energies >= 1014 eV. The array was designed to search for [gamma]-rays from astrophysical sources. The background of cosmic rays is reduced by the selection of muon poor events. The array consists of 1089 scintillation detectors on the surface covering an area of 0.23 km2 and 1024 scintillation counters of 2.5 m2 each, buried 3 m below the surface for muon detection. Each of the surface detectors has its own local electronics and local data storage controlled by a microprocessor. The array is located at Dugway, Utah USA (40.2[deg]N, 112.8[deg]W) where the average atmospheric depth is 870 g/cm2.