Speaker
Description
The CMS Silicon Pixel and Strip detectors have been central to charged-particle tracking since the beginning of LHC operations in Run 1, and, in their Phase-1 configuration, throughout Run 2 and Run 3 under progressively more demanding conditions of luminosity, pileup, and radiation. This talk presents a comprehensive overview of the operational experience accumulated throughout Phase-1, highlighting key lessons learned from more than a decade of detector operation and the collection of several hundred inverse femtobarns of data. We review the evolution of detector performance as a function of increasing integrated luminosity, with particular emphasis on the cumulative effects of radiation damage on silicon sensors and front-end electronics. While the pixel detector was replaced in 2017, both pixel and strip systems have operated over extended periods in an environment of sustained high radiation, making the CMS tracker one of the most extensively irradiated silicon detector systems ever deployed. Strategies developed to mitigate performance degradation—including advanced calibration workflows, alignment procedures, and continuous data-quality monitoring—have enabled the tracker to maintain excellent tracking and vertexing performance throughout its lifetime. Operational challenges such as detector aging, cooling and power stability, and maintenance interventions are discussed, together with the solutions implemented to ensure reliable data-taking up to the end of operations. With the end of Run 3 marking the completion of LHC-era operations for the current CMS tracker, and the transition to Long Shutdown 3 (LS3), these results provide a unique and comprehensive view of silicon detector performance over its full lifetime. This guides the design and operation of future tracking systems for the HL-LHC.