Nuclear Instruments and Methods in Physics Research A

The TORCH, Time of internally Reflected Cherenkov Light, is proposed for the high luminosity upgrade of the LHCb experiment. The detector combines Time-of-Flight and Cherenkov techniques to achieve positive p/K/p separation on a Z3s level in the momentum range below 10 GeV/c. The required time resolution is r 50 ps for single photon signal. In a preliminary R&D phase, we have shown that already commercially available micro-channel plate tubes with 8 � 8 channels fulfil the requirements. Timing properties of the tubes have been investigated with a pulsed laser diode in single photon regime. Key results from these laboratory tests are reported. An excellent timing resolution of o 40 ps is achieved with an efficiency of � 90%.