The LHCb pixel hybrid photon detectors

The Ring Imaging Cherenkov counters of the LHCb experiment use an innovative type of photon detector, the pixel Hybrid Photon Detector. The Cherenkov photons are detected by 484 such devices. The production of the photon detectors is now complete, and the devices have all been fully qualified in dedicated laboratory test facilities. The quantum efficiencies far exceed expectations, with peak values in excess of 30%. We also present the measured ion feedback rates, dead/noisy pixel fractions and dark count rates.