Detection techniques for the RICHs of LHCb

At CERN (The European Laboratory for Particle Physics) the Large Electron-Positron Collider LEP will be substituted by LHC: a Large Hadron Collider. It will be installed in the same tunnel, will collide proton beams with energies around 7-on-7 T eV with a nominal luminosity over the range 1 <-> 5 . 10*34cm 2s 1 or heavy ions such as lead with a total collision energy in excess of 1250 TeV/nucleus. Four experiments will be installed around LHC: ATLAS (A Toroidal Lhc Apparatus), CMS (Compact Muon Solenoid), ALICE (A Large Ion Collider Experiment) and LHCb (the Large Hadron Collider Beauty experiment). The present thesis will describe, after a brief introduction about the whole experiment LHCb and the physics motivations that have led to propose such a detector, the R&D work made on the RICH (Ring Imaging CHerenkov detector) of LHCb to which the author has participated to.