The TORCH PMT, a close packing, multi-anode, long life MCP–PMT for Cherenkov applications

Photek are currently in a three year development programme with CERN to produce a novel square PMT for the proposed TORCH detector which is aimed at the upgrade of the LHCb experiment. The PMT will be microchannel plate based for the inherent timing accuracy that this brings, and has three main novel features that need to be developed: It should be able to produce 5 C/cm 2 of accumulated anode charge without any noticeable degradation in sensitivity. It should be able to achieve a spatial resolution in the “ y ” direction of 0.4 mm and 6 mm in the “ x ” direction through a multi-anode output. Finally it should allow for close packing on 2 opposing sides with an active area fill factor target of 88% in the “ x ” direction but no specific restriction in the “ y ” direction. We will describe the work completed so far including the building and testing of prototypes intended for life-time evaluation, the software modelling of the multi-anode readout and our proposals for the continuation of the project.