Production of 500 pixel hybrid photon detectors for the RICH counters of LHCb

The pixel Hybrid Photon Detector (HPD) has been developed to detect the light produced by the two Ring Imaging Cherenkov (RICH) detectors of the LHCb experiment. The device is a vacuum photon detector equipped with cross-focussing electron optics and a custom anode for photoelectron detection. The production of the 500 such devices that are required to cover the photon detection surface of the LHCb RICH detectors is ongoing. A pre-series of HPDs has been manufactured and their performance assessed in the laboratory. Successful operation has also been confirmed in a test beam. Accelerated ageing tests performed on one pre-series tube show no degradation of performance.