Small Extensive Air Shower detector array – a tool for global cosmic-ray research

The CREDO collaboration studies cosmic-ray related phenomena on a large scale, searching for so called Cosmic-Ray Ensembles (CRE) and other unusual correlations and anomalies of non local nature. Such studies require data on Extensive Air Showers (EAS) and flux of secondary cosmic-ray particles that covers large areas. To perform such measurements, a large network of inexpensive detectors working continuously is necessary, and this work presents a design of such a device. It comprises several small (5 cm $\times$ 5 cm $\times$ 1 cm) scintillator detectors connected in a flat coincidence circuit, which makes it a desktop-size device. This station is designed to work for months or even years without human intervention, as it can send collected data directly to the database through internet. Cost of a complete device ranges from 1000 $\$$ to 2000 $\$$ depending on the number of detectors used. Results of measurements performed with the use of a constructed prototype are compared with estimations based on the analysis of CORSIKA simulations of EAS with Geant4 simulation of scintillator detectors response. They indicate that the proposed device is capable to measure flux of cosmic rays with high statistics and can reliably distinguish EAS events from signals originating from various backgrounds. It is a good candidate for a component of a large-scale network that should be able to not only monitor cosmic-ray flux in real time, but also provide data for studies of CRE and other phenomena related to cosmic rays.