Speaker
Description
Owing to their single photon sensitivity and fast rise time, micro-channel-plate photomultipliers (MCP-PMTs) make a good candidate for photon detectors for the Time Of Internally Reflected Cherenkov light detector (TORCH) that is proposed as part of the phase two upgrade of the LHCb experiment. TORCH has a target time resolution per photon of approximately 70 ps, required to achieve an approximately 3 standard deviation separation of pions and kaons at 10 GeV/c over a 10 m flight distance. A major challenge for TORCH is the high detector occupancy expected during the high-luminosity phase of the LHC, imposing a high requirement for the photon rate for the MCP detector.
A new high granularity 16-by-96 channel MCP-PMT with a directly coupled anode has been developed in conjunction with Photek Ltd. This device is designed to decrease the pixel pitch to 0.55 mm giving improved spatial resolution and importantly lower per-pixel occupancies.
This talk will cover characterisation studies that have taken place on this MCP-PMT: measurements of cross-talk, to determine the spatial resolution of the device; measurements of transit-time spread when applying different biasing potentials, to determine its time resolution; and gain and QE uniformity measurements, to test the uniformity of the device across its active area. Finally, rate capability and expected lifetime were evaluated by gain vs event rate measurements and by studying ion feedback through time delay of after pluses.
