Summary and conclusions

A prototype of the RICH-1 detector has been constructed, and operated in the CERN T9 test beam. Focussed ring images from pions, kaons and protons are detected on a plane of HPD's, using silica aerogel, air and C₄F₁₀ gaseous radiators. The number of detected Cherenkov photons and their measured spatial precision were studied.

The number of detected photons are measured both in data and in simulated event samples. The number of photons observed for both gas and aerogel radiators is found to be in good agreement between data and simulation. The resolution with which the Cherenkov angles are reconstructed is determined and compared with simulation. The expected resolution contributions are in good agreement with their observed values. Both the photon yields and Cherenkov angle resolutions observed in data satisfy the requirements of the proposed RICH-1 detector, as part of the LHCb experiment.

Future work in intended to study the properties of the LHCb RICH-2 detector [12]. This uses an increased focal-length mirror and a single CF₄ gas radiator, to obtain an expected angular resolution of 0.35 mrad [1]. This will allow particle indentification to be extended from the upper limit of 65 GeV/c of RICH-1 to approximately 100 GeV/c. It is also planned to use the RICH prototype system to test various types of new photodetectors currently under development [13].