Status and perspectives of vacuum-based photon detectors

In this overview article vacuum-based photon detectors are reviewed emphasizing their applications in Cherenkov imaging devices. After the discussion of the basic detector stages such as photo cathode, electron multiplication, and (anode) readout, the status and recent progress with single- and multi-anode dynode photomultipliers (PMTs), hybrid (avalanche) photodetectors and microchannel-plate PMTs are presented. For all of these devices selected examples of their current and planned applications in neutrino, astroparticle, and high energy physics experiments are given. Possible future developments and innovations are also debated. The last part of this review is dedicated to a comparison of important performance parameters like particle detection efficiency, gain inside a magnetic field, rate capability, aging and lifetime issues, and radiation tolerance.