Development of the RICH detectors in LHCb

For particle identification, LHCb plans to use two RICH detectors, one covering the charged particle momentum range 1–65 GeV/c using aerogel and C4F10 radiators and the other covering up to 150 GeV/c using CF4 radiator. Hybrid photo diodes (HPD) with 80 mm photocathode diameter are being developed to detect the Cherenkov photons in the wavelength range 200–600 nm. The HPDs encapsulate silicon pixel anodes bump bonded to binary readout chips processed using 0.25 μm CMOS technology. Results obtained with prototype radiators and HPDs in test beams will be presented and the design and development of these RICH detectors will be reviewed.