To identify π and K in the region of 1.0 ∼ 2.5 GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained resul...

abstract: A prototype of Proximity Focussing Ring Imaging Cherenkov counter has been built and tested with several radiator materials using separately cosmic-ray particles and 12 C beam fragmentation products at several energies. Counter prototype and experimental setup are described, and the results of measurements reported and compared with simulation results. The performances are discussed i...

Some conceptual design features of the total internally re ecting, imaging Cherenkov counter (DIRC) are described. Limits of the DIRC approach to particle identi cation, and a few features of alternative DIRC designs, are brie y explored. Invited talk presented at the Third International Workshop on Ring Imaging Cherenkov Detectors Ein-Gedi, Dead Sea, Israel November 15-20, 1998 Work supported ...

A very thin, solid radiator, totally internally reflecting, imaging Cherenkov counter (DIRC) is described. This device is well matched to the hadronic charged particle identification requirements at an asymmetric e+eB Factory.