Recent progress on the observation of Cherenkov light from cosmic air-showers using G-APDs

G-APDs are novel semiconductor photon detectors with a photon detection efficiency (PDE) that potentially can be three times higher than the PDE of a classical photomultiplier (PMT). We study G-APDs with a main focus of their application in air Cherenkov telescopes for very high energy ground-based gamma-ray astrophysics where G-APDs could considerably improve the sensitivity of telescopes. The first detection of Cherenkov light from air showers was reported by us at last years DPG meeting. Here we report on more advanced studies with a small G-APD detector unit installed onto the camera entrance window of the MAGIC telescope, and a quantitative comparison of the performance of G-APDs with the PMTs used in MAGIC. We also discuss next steps to build a full prototype camera on a medium size telescope, and long-term perspectives to use G-APD in Cherenkov telescope arrays, as for example in the CTA project