An improved reconstruction method for the AMIGA detectors

J.M. FIGUERIA, FOR THE PIERRE AUGER COLLABORATION; AUGER COLLABORATION (VER F. SANCHEZ EN PUBL. ADJUNTA)

Bexco

Conferencia; 35th International Cosmic Ray Conference (ICRC); 2017

The Auger Muon and Infill Ground Array (AMIGA) is a muon detector that is currently beingbuilt as part of AugerPrime, the upgrade of the Pierre Auger Observatory. It consists of 30 m2plastic 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 km2. Eachcounter is composed of three 10 m2 modules segmented into 64 scintillator strips. Two positionsof the engineering array were further equipped with "twin" detectors to assess reconstructionuncertainties. AMIGA allows for direct measurement of the muon content of air showers withprimary energies above 10^17 eV. In this work, the detector reconstruction strategy is revisited andthe bias induced by particles traversing two adjacent strips, the so-called corner-clipping effect, isthoroughly analyzed. A bias correction based on end-to-end simulations of both the air showersand the detector response is presented. The improved reconstruction method was applied to experimentaldata acquired by the AMIGA engineering array, and preliminary results of the muoncontent estimator rho450 (muon density 450 m from the shower axis) are presented.