Development of an optical front-end readout system for the LHCb RICH detectors.

The development of a front-end readout system for the LHCb Ring Imaging Cherenkov (RICH) detectors is in progress. The baseline choice for the RICH photon detector front-end electronics is a binary readout ASIC for an encapsulated silicon pixel detector. This paper describes a system to transmit the binary data with address ID and error codes, from a radiation harsh environment while keeping synchronisation. The total data read out for the fixed Level-0 readout period of 900ns is 32x36x440 non-zero-suppressed bits per Level-0 trigger, with a sustained Level-0 trigger rate of 1MHz. Multimode fibres driven by VCSEL devices are used to transmit data to the off-detector Level-1 electronics located in a non-radiation environment. The data are stored in 512Kbit deep QDR buffers.