Evaluation of a new high QE photomultiplier for air Cherenkov telescopes

Abstract We report on the progress of a prototype hybrid photomultiplier (PMT), comprising a high QE, red extended GaAsP photocathode and an avalanche diode as electron bombarded anode with internal gain. These PMTs, with a larger cathode, are planned for the upgrade of the 17 m diameter MAGIC telescope for ground-based gamma (γ) astronomy.