Thesis defense of Martin Bieker

Experiments at particle accelerators, such as the Large Hadron Collider (LHC), are at risk of damage due to the high-energy beams. The Beam Conditions Monitor (BCM) protects the LHCb detector at the LHC. It measures the particle flux with diamond sensors at two positions near the interaction point. If the measured signals exceed safe levels, the BCM automatically triggers a dump of the LHC beams. The LHCb detector was upgraded from 2018 to 2022. Consequently, the BCM needed to be adapted to a five-fold increase in instantaneous luminosity and a new detector geometry. Moreover, the pre-existing BCM hardware card is no longer supported due to an experiment-wide replacement of the readout electronics. This thesis presents the Machine Interface Beam Abort Decision (MIBAD) system as the BCM readout for the post-upgrade era. The development of the system, encompassing hardware, firmware, and software, is detailed. The main emphasis of this work is the implementation of the beam abort decision logic. As a vital part of the BCM safety system, the MIBAD continuously evaluates the beam conditions while meeting strict requirements regarding reliability and availability. A review of the testing and commissioning phase, as well as the experiences in the first months of operation, indicate that these goals have been met. The upgraded BCM, equipped with the MIBAD system, has safeguarded the LHCb detector since June 2023.

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