System test of a prototype LHCb RICH detector

A prototype of the LHCb ring imaging Cherenkov detector has been constructed. The prototype module contained a pre-production pixel hybrid photon detector, mounted on the final photon detector mechanics. The photon detector was read out at the full LHC speed of 40 MHz using the full prototype on-detector RICH electronics readout chain. The readout uses radiation-tolerant FPGA technology, 1.6 GHz optical links and 40 MHz trigger-timing and control (TTC). The photon detector was mounted in a gas vessel and Cherenkov rings have been observed from an N/sub 2/ radiator using electron and pion beams.