First major structure of the future CMS tracker arrives at CERN

The first major mechanical structure of the future CMS tracker has arrived at CERN, as preparations continue for the High-Luminosity LHC (HiLumi LHC). The current tracker needs replacing to prepare the detector for the higher collision rates expected at the HiLumi LHC.

Built and assembled by teams at the IPHC (CNRS/University of Strasbourg) in France, the Tracker Barrel 2S (TB2S) wheel is a 2.3-metre-long structure that forms the outer mechanical framework of the CMS detector’s future tracker.

Designed from lightweight carbon-fibre composite materials, the TB2S wheel combines high mechanical precision with the strength needed to support hundreds of kilograms of detector components. Starting from 2027, more than 4 thousand 2S-type silicon sensor modules, each consisting of two silicon microstrip sensors separated by 1.8 mm, will be installed on the structure.

The project was launched in 2017, with the journey from Strasbourg to CERN taking place in July in a specially designed transport container. It will now undergo further measurements before silicon modules are integrated. This structure will become the backbone of the new CMS tracker, enabling the experiment to record the unprecedented volume of data that will be produced in the HiLumi LHC era.

Find out more on the CNRS IN2P3 website (available in French only).