Characterization of AMIGA binary signals with SiPMs

ANA MARTINA BOTTI; FEDERICO SÁNCHEZ; ALAN FUSTER; MATÍAS ROLF HAMPEL; ALEJANDRO ALMELA; MARÍA BELÉN ANDRADA; ANGEL CANCIO; ALBERTO ETCHEGOYEN; LUCIANO FERREYRO; JUAN MANUEL FIGUEIRA; BEATRIZ GARCÍA; NICOLÁS GONZÁLEZ; EWA HOLT; JOHANNES HULSMAN; MARIELA JOSEBACHUILI; AGUSTÍN LUCERO; DIEGO MELO; SARAH MÜLLER; MATIAS PERLIN; MANUEL PLATINO; DIEGO RAVIGNANI; MATÍAS RONCORONI; CHRISTIAN SARMIENTO-CANO; DAVID SCHMIDT; GAIA SILLI; ÁLVARO TABOADA; BRIAN WUNDHEILER

Otro; Pierre Auger Collaboration internal note; 2018

In this GAP note, lab measurements of 4 scintillator bars identical as those in AMIGA modules are analyzed to asses the main characteristics of the binary signals ofthe detector. Using a muon telescope as external trigger, both muons and background signals were studied at two different discriminator thresholds (2.5 SPEs and 3.5 SPEs) to quantify the signal over noise ratio in different scenarios (both as raw data and after reconstruction strategies). The main source of noise at 2.5 SPEs is produced by SiPMs dark rate. At 3.5 SPEs, the  main  source  of  noise arrives from the bars and cannot be separated from muon signals.  In both scenarios, an inhibition window of 12 digital samples will contain more than 99% of the muon signals. A counting efficiency of (98.5±0.3)% or (98.7±0.5)% setting a discrimination threshold of 2.5 or 3.5 SPEs in 10 m2 modules can be achieved by choosing a proper strategy. Finally, data from module ID 108, at station ID 1764, was also analyzed to compare with results obtained in the lab. The pros and cons of each strategy are discussed.