A large RICH detector is used in NA62 to suppress the muon contamination in
the charged pion sample by a factor of 100 in the momentum range between 15 and
35 GeV/c. Cherenkov light is collected by 1952 photomultipliers placed at the
upstream end. In this paper the characterization of the photomultipliers and
the dedicated Frontend and Data Acquisition electronics are described, the time
resolution and the light detection efficiency measurement are presented.Comment: 15 pages, 11 figure
