Development of a TOP counter for the Super B factory

We will in this paper discuss a novel concept for a ring imaging Cherenkov detector. It measures the time of propagation of the Cherenkov photons in a quartz radiator. The photon detectors are micro-channel-plate photo-multipliers with GaAsP photo-cathodes. The performance has been estimated to give a separation better than 3.5 σ between K and π at 4 GeV / c . This detector, together with a compact focusing system to correct the chromatic effect, will have an even better resolution. We will show that it can achieve more than 4.2 σ separation between K and π at 4 GeV / c . This detector is well suited for experiments at the Super B factory.