University of Wisconsin-Madison Physical Sciences Lab

Learn More: CMS

Photo of PSL Engineer Dan Wenman and Tim Sailor

PSL oversaw the fabrication of part of the enormous particle detector known as the Compact Muon Solenoid (CMS), part of the Large Hadron Collider (LHC) built at CERN. The CMS detector is looking for evidence of the theoretical Higgs particle, and is designed to recognize other particles that might function as alternative to the Higgs within the Standard Model.

PSL was in charge of the end caps of the detector which consist of muon detection chambers sandwiched in between radiation-absorbing steel disks. Each end cap weighs about 3000 tons and has three steel disks 14 meters in diameter. The disks have to be situated upright, like a coin balancing on edge, yet also be extremely stable. Each disk is made of many pieces joined together. The joints must be very strong to resist pulling apart under the 4 Tesla magnetic field created by the solenoid. The disks must also be separable and moveable to have access to the muon chambers and the inner parts of the detector. PSL was involved in the electronics, design, and integration of the muon chambers, which are up to 3.3 meters long.

PSL’s work was so effective that CERN has increased our scope, adding funding for design and integration of beam pipe support during the installation and servicing of the massive detector.

PSL was instrumental in developing tooling for assembly of the detector. PSL employees designed, built and tested in the PSL high bay a manipulator used to install hundreds of muon chambers of differing shapes and masses at many orientations on the CMS end caps.

CMS Outreach has movies and photos. The progress of CMS construction can be viewed through web cams at CERN and in the PSL photo repository for CMS.