An improved reconstruction method for the AMIGA detectors

J.M. FIGUEIRA, THE PIERRE AUGER COLLABORATION (VER A. LUCERO EN LISTA AUTORES ARCHIVO ADJUNTO)

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Conferencia; The 35th International Cosmic Ray Conference, ICRC 2017; 2017

The Auger Muon and Infill Ground Array (AMIGA) is a muon detector that is currently being built as part of AugerPrime, the Pierre Auger Observatory upgrade. It consists of 30 m^2 plastic scintillator counters buried 2.3 m underground and water-Cherenkov detectors at the surface, organized in a periodic 750 m triangular array, and deployed over an area of 23.5 km^2. Each counter is composed of three 10 m^2 modules segmented into 64 scintillator strips. An engineering array of AMIGA is presently operating and includes 7 counters in a hexagonal layout. Two positions were further equipped with "twin" detectors to assess the reconstruction uncertainties. AMIGA allows the muon content of air showers with primary energies above 10^17 eV to be directly measured. In this work, the detector reconstruction strategy is revisited and the bias induced by particles traversing two adjacent strips, the so-called corner-clipping effect, is thoroughly analyzed. A bias correction based on end-to-end simulations of both the air showers and the detector response, as well as the timing distribution of the signals are presented. The impact of the reconstruction method on the arrival times of muons in real data is also shown.