Speaker
Description
The ATLAS Inner Detector will be entirely replaced with a state-of-the-art all-silicon tracking detector (ITk) during the 2026–2028 upgrade, designed to withstand the demanding conditions of the High Luminosity LHC (HL-LHC). The pixel detector, positioned at the core of ITk, will feature 3D sensor technology in the innermost layer (L0), where the expected particle fluence reaches up to 2 × 10¹⁶ neq/cm², while the outer layers (L1–L4) will utilize n-in-p planar hybrid modules with sensor thicknesses of 150 μm and 100 μm.
As part of the ATLAS Upgrade UK's contribution to the ITk project, the UK cluster is responsible for the production, assembly, and quality control of endcap pixel QUAD modules. Each quad module consists of four 2 cm × 2 cm ITkPixV2 readout chips bump-bonded to a single 4 cm × 4 cm planar pixel sensor. The first batch of production modules has now been fabricated and subjected to an extensive characterization campaign. Electrical performance was assessed before and after parylene coating under both warm (+20°C) and cold (-15°C) conditions. Mechanical robustness was evaluated through thermal cycling between high (+45°C) and low (-45°C and -55°C) temperatures, while long-term stability was verified by operating the module under continuous bias for 48 hours. Throughout these procedures, key parameters such as temperature, humidity, low voltage, and high voltage were continuously monitored, with an interlock system ensuring operational safety.
To validate tracking performance, one of the characterized modules underwent a beam test at CERN using a 120 GeV pion beam, demonstrating high signal efficiency. This presentation will provide an overview of the endcap pixel module production process, focusing on key characterization results and performance evaluations at various stages.
| Workshop topics | Detector systems |
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