The Large Hadron Collider (LHC) at CERN in Switzerland is the largest scientific experiment ever constructed. As the world’s most powerful particle accelerator, it allows scientists to study the fundamental building blocks of matter and better understand how the universe works.
One of the LHC’s two primary detectors is the Compact Muon Solenoid (CMS), a massive instrument designed to detect particles created during high-energy collisions. Despite its name, the CMS detector is one of the largest and most sophisticated particle detectors ever built.
For more than 15 years, PSL partnered with CERN to help design, build, and install critical components of the CMS detector, contributing engineering expertise to one of the world’s most ambitious scientific projects.
Engineering the CMS Endcaps
SL’s primary responsibility was the design, integration, assembly, and installation of the two CMS endcaps. Each endcap stands roughly the height of a five-story building, weighs nearly 3,000 tons, and contains more than two million hair-thin detection wires and 310,000 channels of high-speed electronics. The endcaps support the detector’s muon chambers, which identify and track muons produced during particle collisions, while massive radiation-absorbing steel disks provide structural support and shielding.
Each endcap contains three steel disks measuring 14 meters in diameter, positioned vertically while supporting thousands of tons of material. The structures had to withstand the immense forces generated by the detector’s 4-tesla superconducting magnet while remaining accessible for maintenance. PSL also led the design and integration of the muon chambers, some measuring up to 3.3 meters long, ensuring they were precisely positioned and connected to the detector’s sophisticated electronics.
In addition to engineering the detector, PSL developed specialized tooling to support assembly. Engineers designed, built, and tested a custom manipulator capable of installing hundreds of muon chambers with varying sizes, weights, and orientations. One of the project’s defining milestones came during installation, when each fully assembled endcap was carefully lowered 100 meters underground into the experimental hall without damaging a single detection wire, a remarkable achievement considering the size and complexity of the structures.
Advancing Particle Physics
The CMS detector records and analyzes particles produced during collisions inside the LHC, helping researchers test theories about the fundamental structure of matter. It played a key role in the discovery of the Higgs boson and continues to support experiments in particle physics.
PSL’s successful work on the CMS project led CERN to expand the company’s responsibilities to include the design and integration of the beam pipe support system during installation and servicing of the detector.
The CMS project demonstrates how large-scale scientific research depends on close collaboration between scientists and engineers. PSL’s contributions helped deliver critical systems that continue to support the detector’s operation today