The ATLAS experiment will be upgraded with a new Inner Tracker (ITk) detector for the High-Luminosity phase of the Large Hadron Collider.
The ITk, a fully silicon-based detector, will replace the current Inner Detector, enhancing its tracking performance through increased acceptance and improved spatial and time resolution.
The ITk will operate in a very harsh radiation environment, requiring an optimal cooling system to deliver effective performance and protect the components from damage.
In the ITk pixel outer endcaps, the cooling is provided by bi-phase CO$_2$ that flows through the local supports, carbon-based structures that secure the pixel sensors in place.
The design and construction of these local supports present several challenges, which have led to an extensive R&D campaign over the past few years that included testing numerous prototypes.
The local support assembly demands meticulous procedures and state-of-the-art technology to achieve the high level of precision necessary to meet the design specifications and prevent operational failures.
A series of Quality Control tests, including metrology and infrared thermography measurements, have been implemented to assess the thermo-mechanical properties of the local supports and identify defective objects.
This document will cover the techniques used, the major challenges encountered during the R&D phase, and the solutions developed. Additionally, highlights from the ongoing production campaign will also be shown.