LHCb RICH 2 engineering design review report

The LHCb detector is a single arm spectrometer designed to exploit the large number of b-hadrons produced at the LHC in order to make precision studies of CP asymmetries and of rare decays in the B-meson system. It is therefore essential for the experiment that the detector configuration includes a particle identification system with high separation power between kaons and pions. We will present in this note the engineering solutions for the lightweight, high precision Ring Imaging Cherenkov detector, RICH2, of the spectrometer. The design is built around a large space frame used as a high stability support for the optical system and as a supporting structure for the magnetic shielding needed for the photon detectors. All material not essential for the operation of the detector is located outside the acceptance of the spectrometer. The space frame also defines the Cherenkov gas volume.