Study on the optical fiber attenuation of the UMD using the integrator channel

F. SANCHEZ (VER ADJUNTO)

Malargüe

Otro; PUBLICACION INTERNA COLABORACION AUGER (GAP NOTE); 2021

Observatorio Pierre Auger

In this GAP note, the attenuation in the optical fiber of the modules of the Underground MuonDetector (UMD) is studied using two datasets: ADC calibration files and shower events. For bothcases, the mean charge generated by a single muon was obtained for each scintillator strip. Thisobservable presented a clear anti correlation with the fiber length of the strip, which is consistentwith the expectations from extrapolations of laboratory measurements. An effective attenuationlength was obtained for both datasets by the means of an exponential fit, showing good agreementbetween them and with the laboratory. Finally, charge values of the single-muon signal obtainedwith the calibration files were found to be systematically higher than those in the shower events.This is consistent with ADC calibration files being biased towards muons with larger zenith angles.