Tests of a proximity focusing RICH with aerogel radiator and flat-panel multi-anode PMTs (H8500)

A study was carried out to measure the performance of a proximity focusing RICH with aerogel as radiator and flat-panel multi-anode PMTS as detectors of Cherenkov photons. The yield and resolution were measured by using a pion test beam. The parameters of the counter were determined for various aerogel materials, densities, thicknesses, angles of incidence, as well as a function of the incoming beam momentum. Finally, the results were used to study the feasibility of such a counter for the upgrade of the Belle spectrometer for the high luminosity operation.