Techniques for Measuring Aerosols using the Central Laser Facility at the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION; GARCIA, B (400 AUTORES EN ORDEN ALFABETICO)

JOURNAL OF INSTRUMENTATION

IOP PUBLISHING LTD

Lugar: Londres; Año: 2013 vol. 8 p. 1 - 28

1748-0221

The Pierre Auger Observatory in Malargue, Argentina, is designed to study the properties of ultra-high energy cosmic rays with energies above 1018eV. It is a hybrid facility that EMploys a Fluorescence Detecor to perform nearly calorime tric measurements of Extensive Air Shower energies. To obtain   reliable calorimetric informat ion from the FD, the atmospheric conditions at the observatory need to be continuously monitored during data acquisition. In particular, light attenuation due to aerosols is an important atmospheric correction. The aerosol concentration is highly variable, so that the aerosol attenuation needs to be evaluated hourly. We use light from the Central Laser Facility, located near the center of the observatory site, having an optical signature comparable to that of the highest energy showers detected by the FD. This paper presents two procedures developed to retrieve the aerosol attenuation o f fluorescence light from CLF laser shots.Cross checks between the two methods demonstrate that results from both analyses are compatible, and that the uncertainties are well understood. The measurements of the aerosol attenuation provided by the two procedures are currently used at the Pierre Auger Observatory to reconstruct air shower data.