MARTA aims at measuring directly the muon content of the cosmic ray air-showers
Eur. Phys. J. C (2018) 78:333 https://doi.org/10.1140/epjc/s10052-018-5820-2
Muons are detected by Resistive Plate Chamber (RPC) detectors installed beneath the Auger water-Cherenkov detectors. The water shields the RPCs from the other particles.
An engineering array of 8 stations (and 36 RPCs) will be used for detailed studies of “low energies” air-showers, for which the first interactions are closer to those tested at the LHC.
The development of autonomous, low gas flux, large surface RPCs, has been a large effort of LIP in previous years. Many RPC planes have been tested for outdoor operation at Auger. The technology was tranfered to Brazil, that participated in the production and assembly of the MARTA modules.