Summary

The major outstanding issue for the LHC-B RICH detector is the demonstration of a photodetector that matches LHC-B requirements. For the pixel HPD it is envisaged to produce and test a 80 mm diameter tube whilst a pixel chip is developed in parallel that meets the experimental needs. Test in 1998 are planned for the pad HPD using the 2048 pad detector under vacuum with the designed focussing and then eventually with a bialkali photocathode.

The RICH prototype tests have been successful. Clear Cherenkov rings from gas and aerogel radiators have been observed for the first time using HPD's as photon detectors. The preliminary measured photon yields are compatible within 30% of expectations based on simulations. Further analysis of the data is investigating the reconstruction resolution of the Cherenkov angle for each recorded hit from both the gas and aerogel radiators. Further prototype testbeam runs are being planned to study RICH 2. It is also planned to use the RICH prototype to test the various photodetectors as they become available.