Monte Carlo simulations for the Pierre Auger Observatory using the VO auger grid resources

PIERRE AUGER COLLABORATION; A. MARIAZZI

Berlin

Conferencia; 37th International Cosmic Ray Conference (ICRC2021); 2021

The Pierre Auger Observatory, located near Malargüe, Argentina, is the world?s largest cosmic-raydetector. It comprises a 3000 km2surface detector and 27 fluorescence telescopes, which measurethe lateral and longitudinal distributions of the many millions of air-shower particles producedin the interactions initiated by a cosmic ray in the Earth?s atmosphere. The determination of thenature of cosmic rays and studies of the detector performances rely on extensive Monte Carlosimulations describing the physics processes occurring in extensive air showers and the detectorresponses.The aim of the Monte Carlo simulations task is to produce and provide the Auger Collaborationwith reference libraries used in a wide variety of analyses. All multipurpose detector simulationsare currently produced in local clusters using Slurm and HTCondor. The bulk of the showersimulations are produced on the grid, via the Virtual Organization auger, using the DIRACmiddleware. The job submission is made via python scripts using the DIRAC-API.The Auger site is undergoing a major upgrade, which includes the installation of new types ofdetectors, demanding increased simulation resources. The novel detection of the radio componentof extensive air showers is the most challenging endeavor, requiring dedicated shower simulationswith very long computation times, not optimized for the grid production.For data redundancy, the simulations are stored on the Lyon server and the grid Disk Pool Managerand are accessible to the Auger members via iRODS and DIRAC, respectively. The CERN VMFile System is used for software distribution where, soon, the Auger Offline software will also bemade available.