MACARIO is a detector based on resistive plate chambers (RPCs) technology, using freon gas as a revealing medium. The study of East-West asymmetry is a fundamental phenomenon which happens in every place of the world but depends on the latitude and altitude of the detector which relates with the geomagnetic cutoff rigidity. This kind of detector is particularly useful for training students who are starting to get involved in astroparticle and particle physics and for education and outreach activities due to the compact size which allows them to familiarize themselves with instrumentation and reconstruction techniques employed on bigger projects.

The low energy cosmic rays (E < 1 TeV) are more abundant with a rate of 10’000 particles per square meter per second and down to 1 particle per square meter per second as the energy increases. One remarkable effect produced by secondary cosmic ray muons is the East-West asymmetry which implies the arrival of more particles from the West than East due to the Earth magnetic field. For these typical energies and up to a few hundred of GeV, muons mainly interact with matter by ionization, losing energy at a fairly constant rate of about 2 MeV per g/cm2. MACARIO detector is a compact muon telescope consisting of four resistive plate chambers (RPCs) with great angular and temporal resolution which records the passage of muons that reach the ground with a mean energy of 4 GeV at sea level. On this work we describe the design of MACARIO detector, the results for the asymmetry factor at different zenith angles, and the comparison of these results with simulations by CORSIKA software.