TORCH — an innovative high-precision time-of-flight PID detector for the LHCb upgrade

TORCH is a Cherenkov time-of-flight detector being developed as a particle identification system for the upgraded LHCb experiment. The DIRC-type detector is located at 10m distance from the interaction point with an area of 30m2 and is formed from 10mm thick synthetic amorphous fused silica plates. In this Cherenkov radiator the photons that propagate by total internal reflection to the plate edge are focussed onto an array of position-sensitive micro-channel plate sensors. Combining the photon timings the goal is to achieve a σ = 15 ps timing resolution per particle, yielding 3σ pion-kaon separation up to 10 GeV/c or better. Requirements for the photon detectors are presented together with preliminary prototype results. Preparations for the upcoming test beam are discussed. Optical design studies have been performed for using one of the available bar boxes of the BaBar DIRC detector containing assembled quartz radiator bars in a future test beam experiment.