The AMIGA enhancement of the Pierre Auger Observatory

S MALDERA FOR THE PIERRE AUGER COLLABORATION, B. WUNDHEILER

Conferencia; International Conference on Advanced Technology and Particle Physics; 2013

The AMIGA (Auger Muons and Infill for the Ground Array) enhancement of the Auger Surface Detector consists of a 23.5 km^2 infill area instrumented with water?Cherenkov detector stations accompanied by 30 m^2 of scintillator counters, buried 2.3 m underground. The spacing of 750 m between the surface detectors extends the energy range as low as 3 × 10^17 eV, thus allowing the study of the energy region where the transition between galactic and extra?galactic cosmic rays is expected to take place. We describe the reconstruction of the events observed with the infill water?Cherenkov detector array and the derived energy spectrum. We also discuss the basic properties of the muon detector modules obtained from measurements and tests during the construction phase and from the first data in the field.