Hybrid Extensive Air Shower Detector Array at the University of Puebla to Study Cosmic Rays

Abstract

We describe the design of an extensive air shower detector array built in the Campus of the University of Puebla (located at 19◦N, 90◦W, 800 gcm−2) to measure the energy and arrival direction of primary cosmic rays with energies around 10 eV. The array consists of 18 liquid scintillator detectors (12 in the first stage) and 6 water Cherenkov detectors (one of 10 m cross section and five smaller ones of 1.86 m cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m. In this paper we discuss the calibration and stability of the array, and discuss the capability of hybrid arrays, such as this one consisting of water Cherenkov and liquid scintillator detectors, to allow a separation of the electromagnetic and muon components of extensive air showers. This separation plays an important role in the determination of the mass and identity of the primary cosmic ray. This facility is also used to train students interested in the field of cosmic rays.