AMIGA at the Auger Observatory: the scintillator module testing system

MANUEL PLATINO; MATIAS ROLF HAMPEL; ALEJANDRO ALMELA; ALEJANDRO KRIEGER; DANIEL GORBEÑA; ARMANDO FERRERO; GONZALO DE LA VEGA; AGUSTÍN LUCERO; FEDERICO SUAREZ; MARIELA VIDELA; OSCAR WAINBERG; ALBERTO ETCHEGOYEN

JOURNAL OF INSTRUMENTATION

IOP PUBLISHING LTD

Lugar: Trieste; Año: 2011 vol. 6 p. 1 - 17

1748-0221

AMIGA is an extension of the Pierre Auger Observatory that will consist of 85 detector pairs each one composed of a surface water-Cherenkov detector and a buried muon counter. Each muon counter has an area of 30 m^2 and is made of scintillator strips with doped optical fibers glued to them, which guide the light to 64 pixels photomultiplier tubes. The detector pairs are arranged at 433 m and 750 m array spacings. In this paper we present the testing and initial calibration system for the scintillator modules that constitute each muon counter of AMIGA. The scintillator modules are tested with a "scanner" that consists of an x/y positioning system that moves a 5 mCi 137Cs radioactive source over the module taking data at fixed locations. The scanner both tests the module for possible fabrication defects and stores the light-attenuation curve parameters. A complete scanning process of a 64 strip scintillator module has been performed and results are presented. Also, attenuation curves obtained with scanner and with background muons are compared with satisfactory results.