Study of standalone RPC detectors for cosmic ray experiments in outdoor environment

The capability of covering very large areas at low cost, besides showing excellent performance in many aspects, motivated the application of RPCs to Nuclear and High Energy Physics and also to Cosmic Ray Physics research in experiments such as COVER-PLASTEX and ARGO/YBJ. The RPCs capabilities could be used to measure new observables, or to improve resolution of actual ones, namely the sensitivity to the details of the depth development of extensive air showers from muon time distributions. Since these detectors so far have been used in indoor conditions, the main challenge is to develop detectors that can operate under harsh conditions, low energy budget, low cost per unit area, with very sparse opportunities for maintenance, and with good resilience to environmental conditions. Since the greatest challenges are the high voltage distribution/insulation and gas tightness we confine the detector in a sealed plastic box. With this approach we decouple the readout electrodes from the high voltage, allowing for different readout electrode distributions and respecting the requirements of each system with reduced effort. The detector is impervious to humidity and requires only 0.4 cm3/min of gas flow rate, equivalent to 1 kg/year of R-134a.