Study of the fluorescence detector upgrade of the Auber observatory for cosmic rays

D.G. MELO, A. ETCHEGOYEN, M.I. MICHELETTI AND A.C. ROVERO

Cuzco, Peru

Simposio; VII Latin american symposium on nuclear physics and applications; 2007

The Pierre Auger Observatory (PAO) consists of two kinds of detectors: fluorescence detectors (FD) and surface detectors (SD). In this work we evaluate the effect, on the number and quality of the reconstructed events, of new telescopes (or "eyes") with an enhanced field of view (FOV) up to approximately 60 degrees in elevation. By using numerical simulations, we calculated the mean total efficiency of the eye, the resolution of reconstruction of the basic parameters that characterize the primary cosmic rays (CR) and the elongation rate. To do this, we considered showers of protons and irons with energies of log(E/eV) between 17.50 and 18.25, impinging inside a circular area, placed in front of the eye at distances varying between 3.5 and 11 km. The extension of the FOV of the eye turns to be very convenient for the selected energy range, due to the fact thatthe atmospheric depths where the showers develop their maximum number of secondary particles (Xmax) are directly observed by the extended eye in most of the cases. Being this y^max a parametersensible to the chemical composition of the primary cosmic ray,  its correct determination is very important in composition studies.