GLAS-PPE/1999-2125th September 1999
a1University of Cambridge, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK. a2CERN, PPE Division, 1211 Geneva 23, Switzerland. a3University of Glasgow, Department of Physics, Glasgow G12 8QQ, UK. a4Imperial College of Science Technology & Medicine, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK. a5University of Oxford, Department of Nuclear Physics, Keble Road, Oxford OX1 3RH, UK. a7Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK.
A prototype Ring-Imaging Cherenkov detector has been operated in a charged particle test beam. Cherenkov photons are imaged onto a plane of hybrid photo-diode detectors. The geometrical arrangement of the prototype and data-taking conditions are described. An analysis of the detector performance, using silica aerogel, air and C4F10 gas radiators, is presented. The photon yields and observed Cherenkov angle resolutions are found to be in good agreement with Monte Carlo simulation and satisfy the requirements of the RICH 1 detector in the LHCb experiment.