A novel camera type for very high energy gamma-astronomy

Full text: Results of the FACT project are presented. The significant progress of semiconductor photodetectors in the past years, resulting in the development of Geiger-mode avalanche photodiodes (G-APD), allows to realise a novel camera type for imaging air Cherenkov telescopes. The project 'First G-APD Camera Test' (FACT), initiated by ETH Zuerich, uses G-APDs to measure Cherenkov light from airshowers originating from very high energetic gamma-rays. G-APDs offer enhanced properties compared to standard photomultipliers (e.g. compactness, homogeneous angular acceptance and tolerance of bright light). The camera is foreseen for the DWARF telescope which will be dedicated to the long-term monitoring of bright blazars. (author)