Fabrication and testing system for plastic scintillator muon counters used in cosmic showers detection

摘要

In this paper we present the fabrication, testing and initial calibration system for scintillator modules to beused as muon counters for cosmic ray particle shower detection, developed in the ITeDA facilities. Each muon counterhas an area of 30 m2, divided in three scintillator modules of 10 m2, and is made of plastic scintillator strips with dopedoptical fibers glued to them, which guide the light to 64 pixel photomultiplier tubes. Each module is buried to detectonly the muon component of the cosmic shower. The scintillator modules are tested with a 'scanner' that consists of anx - y positioning system that moves a 5 mCi137Cs 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. Acomplete description and specifications of the fabrication process and materials used for the construction of the scintillatormodules is presented. Also, a complete scanning process of a 64 strip scintillator module is performed and results arepresented and compared with an initial calibration performed with a muon telescope.