Speaker
Description
In the last two decades Resistive Plate Chambers were employed in the Cosmic Ray Experiments COVER-PLASTEX and ARGO/YBJ. In both experiments the detectors were housed indoors, likely owing to gas distribution requirements and the need to control environment variables that directly affect RPCs operational stability. But in experiments where Extended Air Shower (EAS) sampling is necessary, large area arrays composed by dispersed stations are required, making this kind of approach impossible. In this situation, it will be mandatory to have detectors that could be deployed in standalone stations, with very sparse opportunities for maintenance, and with good resilience to environmental conditions. Aiming to meet these requirements, we started some years ago [1] the development of RPCs for Autonomous Stations. The results from indoor tests and measurements were very promising [2], both concerning performance and stability under very low gas flow rate, which is the main requirement for Autonomous Stations. In this work we update the indoor results and show the first ones concerning outdoor stable operation. In particular, a dynamic adjustment of the high voltage is applied to keep gas gain constant. Evolution in time of E/N, background current/rate and efficiency will be presented. [1] L. Lopes et al., Study of standalone RPC detectors for cosmic ray experiments in outdoor environment, 2013 JINST 8 T03004. [2] L. Lopes et al., Study Resistive Plate Chambers for the Pierre Auger array upgrade, 2014 JINST 9 C10023.
