Readout of the LHCb pixel hybrid photon detectors

The LHCb experiment will use two Ring-Imaging Cherenkov counters equipped with pixel hybrid photon detectors (HPDs) to measure Cherenkov light generated by high-energy particles traversing a radiative medium. Data from these detectors must provide efficient pattern recognition whilst coping with the environmental demands of LHCb: 25 ns time precision, up to 4% channel occupancy and 1 MHz selective frame readout rate. Dedicated CMOS electronics have been developed to meet the requirements of the HPD, together with special packaging and interconnect techniques which withstand the harsh production processes of the detector. Successful prototypes have been fabricated and tested and results are presented. Large-scale production has started in collaboration with European hi-tech industry and the individual steps in the process are described.