Status and performance of the underground muon detector of the Pierre Auger Observatory

A. BOTTI; AUGER COLLABORATION (VER F. SANCHEZ EN PUBL. ADJUNTA)

Berlin

Conferencia; 37th International Cosmic Ray COnference (ICRC 2021); 2021

The Auger Muons and Infill for the Ground Array (AMIGA) is an enhancement of the Pierre AugerObservatory, whose purpose is to lower the energy threshold of the observatory down to 10^16.5eV, and to measure the muonic content of air showers directly. These measurements will significantlycontribute to the determination of primary particle masses in the range between the second kneeand the ankle, to the study of hadronic interaction models with air showers, and, in turn, to theunderstanding of the muon puzzle. The underground muon detector of AMIGA is concomitantto two triangular grids of water-Cherenkov stations with spacings of 433 and 750 m; each gridposition is equipped with a 30 m2 plastic scintillator buried at 2.3 m depth. After the engineeringarray completion in early 2018 and general improvements to the design, the production phasecommenced. In this work, we report on the status of the underground muon detector, the progressof its deployment, and the performance achieved after two years of operation. The detectorconstruction is foreseen to finish by mid-2022.