Leakage Current in the ATLAS Pixel Detector in LHC Run-3 and its Implications for Radiation Damage in Silicon Detectors.

The ATLAS Pixel detector, the innermost sentinel of the experiment, is continuously exposed to extreme radiation from proton-proton collisions at the LHC. Positioned just centimeters from the interaction point, its silicon sensors endure a bombardment that fractures their crystal lattice, fundamentally modifying their structure and degrading their performance. This damage manifests as a key operational signature: a rising leakage current.

This talk presents a diagnostic study of this leakage current from LHC Run-3, serving as a direct measure of accumulated radiation dose. We reveal how the leakage current correlates with integrated luminosity, local temperature inhomogeneities, and the sensor’s precise geometric position. Our findings demonstrate that radiation damage is dominated by proximity to the interaction point, exhibits no azimuthal dependence, and is acutely sensitive to thermal fluctuations.

These results are far more than diagnostic; they are vital for validating radiation damage models and informing the operational limits of the current detector. Furthermore, this understanding is crucial for designing the radiation-hard systems required for the high-luminosity era of the LHC, ultimately ensuring the future reliability and discovery potential of physics at the energy frontier.