The HERA-B ring imaging Cherenkov detector

The HERA-B RICH system is designed and prototyped. It will be fully assembled by the end of 1998. It will constitute an efficient and reliable means for charged particle identification over the momentum range 4–80GeV/c. Its principal role will be to provide B0(B̄0) flavor tagging via kaon-pion separation. An overall description of the design features is provided. The principal innovation is the design of the focal plane photon detector. This employs Hamamatsu R5900 multianode photomultipliers exclusively. Each PMT is outfitted with a specially designed UVT acrylic lens telescope system for light collection purposes.