Development of lightweight carbon-fiber mirrors for the RICH 1 detector of LHCb

摘要

The design, manufacture and characterization of lightweight carbon-fiber spherical converging mirrors for the RICH 1 Cherenkov detector of the LHCb experiment at CERN are described. The mirrors need to be lightweight to minimize the material for traversing particles and fluorocarbon-compatible to avoid degradation in the C_4F_(10) gas radiator of RICH 1. Four large-sized carbon-fiber mirrors covering a total surface area of ～2 m~2 were installed in RICH 1 in July 2007. The mirrors have a radius of curvature of ～2700 mm, a high reflectivity of ～90% in the 200-600 nm wavelength band, a low areal density of ～5kg/m~2 equivalent to ～1.2% of a radiation length. Results of the radiation and fluorocarbon testing of the mirror prototypes are also reported.