Speaker
Description
The High-Granularity Timing Detector (HGTD) is a key component of the ATLAS Phase-II upgrade for the HL-LHC, employing Low-Gain Avalanche Detector (LGAD) sensors to provide precise timing and mitigate pile-up in the forward region. Each LGAD module is mounted on a dedicated Support Unit (SU) — 48 types of pure-PEEK structures, of which 839 are being fabricated. The SUs must hold the modules in accurate position to maintain good thermal contact with the aluminium cooling plate and protect the wire bonds, so any out-of-tolerance unit could degrade alignment, cooling, or bonding — making dimensional quality control of every SU essential. This talk summarizes the quality-control methodology and status of the SU measurements at IHEP. Key parameters include module height, free-state flatness, cavity width and M2 hole position, all verified with an automated analysis tool driven by a per-SU configuration. Results from the first batch of FO05 and FO06 SUs under free conditions will be presented, demonstrating the identification of out-of-tolerance modules and holes for staged acceptance of the 839-unit production.
