Air Shower Measurement with a SiPM Based Scintillator Detector

We developed an optical module based on silicon photomultipliers (SiPMs) designed for a wide variety of applications especially in scintillator detectors and laboratory measurements. To test the module, a Scintillator Surface Detector developed for AugerPrime, the upgrade of the Pierre Auger Observatory, was modified and is operating in the Argentinean Pampas. It is the first SiPM based scintillator detector successfully measuring air showers induced by ultra-high energy cosmic rays. The main goal of the development was exploiting the advantages of SiPMs compared to conventional photomultiplier tubes, specifically their mechanical and optical robustness, their high photon detection efficiency and their lower operating voltage. Two SiPMs are read out in parallel and equipped with light guides to increase the sensitive area. Their signal is split into three independent gain stages to exploit the full dynamic range from a breakdown of a single SiPM cell to a simultaneous breakdown of all cells. The bias voltage supply, which corrects for the temperature, is integrated into the module, and it is powered and controlled through a USB connection. This setup guarantees an easy usage of the module in many applications. We present the module and will show results from the field measurements.