Characterization of AMIGA binary signals with SiPMs

A. BOTTI; F. SÁNCHEZ; A. FUSTER; M. R. HAMPEL; A. ALMELA; B. ANDRADA; A. CANCIO; A. ETCHEGOYEN; L. FERREYRO; J. M. FIGUEIRA; B. GARCÍA; N. GONZÁLEZ; E. HOLT; J. HULSMAN; M. JOSEBACHUILI; A. LUCERO; D. MELO; S. MÜLLER; M. PERLIN; M. PLATINO; D. RAVIGNANI; M. RONCORONI; C. SARMIENTO-CANO; D. SCHMIDT; G. SILLI; A. TABOADA; B. WUNDHEILER

PUBLICACION INTERNA DE LA COLABORACION INTERNACIONAL AUGER

Pierre Auger Observatory

Año: 2018

2250-835X

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 of 25 the detector. Using a muon telescope as external trigger, both muons and background signals were studied at two dierent discriminator thresholds (2.5 SPEs and 3.5 SPEs) to quantify the signal over noise ratio in dierent 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 30 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 eciency 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 35 results obtained in the lab. The pros and cons of each strategy are discussed.