CHICOS Detector Stations

The California HIgh school Cosmic ray ObServatory (CHICOS) is a large area (presently 400 square kilometers) ground array for the study of ultra high energy cosmic rays located in the Los Angeles area. Each CHICOS station employs two 1m scintillation counters from the decommissioned CYGNUS array [1] instrumented with 3” or 5” photomultiplier tubes from the decommissioned Palo Verde neutrino experiment [2]. We have developed a PC-based data acquisition system for these remote stations. Data are processed and transferred automatically over the internet once per day. At present there are 43 sites operating reliably.