Support document for LHCb RICH front-end electronics

Three types of Photo-detector are currently being investigated for the possible use in the LHC-B RICH detector.There are 340000 channels of electronics and, depending on the choice of photo-detector, a probable signal of 5000e/photon has to be processed. The signals are stored at a rate of 40Mhz and selectively read-out at two levels at 1Mhz and 40Khz to output buffers for further processing. This note briefly describes the photo-detectors and possible implementation of schemes to capture and read-out the data.1