MaPMT Relative Efficiency Measurements for the LHCb RICH Upgrade

Abstract

The Large Hadron Collider beauty experiment (LHCb) at CERN is aimed to study flavor-physics. The Ring Imaging Cherenkov detector system (RICH), which provides particle identification, have been operating successfully since 2010. During the second Long Shutdown of the LHC of 2019-2020, the RICH detectors will be upgraded to maintain the excellent PID performance with a five-fold increase of instantaneous luminosity. In addition, the detector will be readout at the full LHC bunch-crossing rate of 40 MHz using a flexible software based trigger. To cope with that changes the current hybrid photon detectors will be replaced by Hamamatsu R13472 multi-anode photomultipliers (MaPMT) with external brand new frontend electronics. The new photodetectors and the associated electronics have been subjected to calibration procedures. The high-voltage working point determination, relative efficiency measurements of MaPMT pixels and their calibration procedure for the RICH detector system will be presented.