Reliability assessment of CMS Drift Tubes readout electronics for the HL-LHC upgrade

The new readout electronics of the CMS Drift Tubes detector has been evaluated in terms of its reliability. Starting with a brief overview of the main functionalities of the board, operating requirements and critical elements, an initial estimate of the hardware robustness with respect to expected faults over time is then presented. A global figure of merit is derived by means of a custom-developed software model accounting for the reliability data of each component and applying proper derating based on worst-case operating conditions. This also provides the opportunity to highlight some peculiar design choices intended to limit the various stress sources related to the detector operating environment. Finally, the functional robustness of the board with respect to ionizing radiation is presented, discussing the setup, objectives, and results of two measurement campaigns that were undertaken for this purpose at the Trento Proton Therapy Centre. Most importantly, apart from analysing the type and conditions of occurrence of every observed component failure, the resilience of the hardware/firmware combination is debated, projecting the expected need for intervention during the future High-Luminosity (HL) LHC runs.