Multianode Photomultiplier Tubes for the LHCb RICH Photodetectors

The LHCB experiment is being built at the Large Hadron Collider facility at CERN in Geneva, Switzerland. The aim of the experiment is the precise measurement of CP violation parameters in the B-meson system. A critical requirement of the detector is a good pion/kaon separation provided by two Ring Imaging CHerenkov (RICH) counters. This thesis presents studies on the feasibility of using Multianode PhotoMultiplier Tubes (MaPMTs) as photodetectors in the LHCb RICH. We will establish the performances of MaPMTs in magnetic fields and also investigate how to shield them. Finally we present a testbeam analysis of a cluster of MaPMTs equipped with lenses at the CERN PS beam. The purpose of this testbeam was to demonstrate the operation of MaPMTS in a RICH prototype using the LHCb readout electronics

Performance of multi-anode photomultiplier tubes for the LHCb RICH detectors

An array of Multi-anode Photomultiplier Tubes (MaPMT) was evaluated for use in the LHCb Ring Imaging Cherenkov (RICH) detectors using a prototype RICH detector in a charged particle beam. The MaPMT performance was measured with different radiator gases with and without lenses. The performance of the MaPMTs in terms of photon yield and pixel cross-talk is presented. (c) 2005 Elsevier B.V. All rights reserved

Performance of 8- and 12-dynode stage multianode photo-multipliers

We report on studies of 64-channel Multianode Photo-Multiplier Tubes (MaPMTs) as photo-detectors for Ring Imaging CHerenkov (RICH) counters. The newly available 8-dynode stage MaPMT was tested in particle beams at CERN. The MaPMT signals were read out directly with the Beetle1.2 chip which was designed for the LHCb environment and operates at 40 MHz. The photon yield and signal losses were determined for a cluster of 3×3 close-packed MaPMTs. The performance of the 8-dynode stage MaPMT was compared to that of the 12-dynode stage MaPMT which has a larger intrinsic gain