Speaker
Description
The Barrel Timing Layer and Tracker Support Tube (BTST) is a 2.4-meter diameter, 5.3-meter long composite sandwich structure designed to provide primary mechanical support for the Barrel Timing Layer, Outer Tracker, and Inner Tracker detectors of the CMS detector for the HL-LHC. This presentation provides updates on mechanical loading tests, metrology, and simulation validations following a mock loading exercise conducted after a transportation-related road accident in June 2025. The talk also addresses findings from manufacturing quality control and addresses the next steps in the integration and installation of the BTST at CERN. Key learnings from the development of accurate material models—reflecting as-manufactured properties and realistic boundary conditions necessary to simulate worst-case loading scenarios expected during installation into the calorimeter with the temporary support structure (Eiffel tower)—are discussed. The realistic installation and integration simulation are used to establish safe operating procedures, and evaluate any potential modifications needed to external temporary supports. Additionally, the metrology techniques used for validation of the BTST, along with plans for QA/QC, will be presented. This talk serves as a follow-up to previous presentations at FTDM 2024, which covered the initial design, simulation, and manufacturing process of the BTST.