The RICH with Aerogel for the LHCb Experiment

Abstract

Silica aerogel is one of the three radiators chosen for the Ring Imaging Cherenkov system of the LHCb experiment, designed to provide a powerful particle identification tool. Aerogel, in the RICH detector [1], covers the momentum range 1−10 GeV/c for π/K separation. The material is a hygroscopic quality of silica aerogel produced by the Boreskov Institute for Catalysis in collaboration with the Budker Institute of Nuclear Physics in Novosibirsk. A big effort has been put during the last few years to obtain large size tiles with high transparency and good uniformity with respect to refractive index variations from point to point, to the level of 1% of (n − 1), with n =1 .03 at λ = 543. 5n m. At the end of this R&D period, large size silica aerogel tiles with unprecedented optical quality have been delivered to us for testing, making it realistic to achieve the requested resolution in the Cherenkov angle measurement.