CERN (Conseil Européen pour la Recherche Nucléaire) is one of the world’s most prestigious organisations for scientific research. The development of the LHC, which sits 100 metres underground below the French-Swiss border, ranks as one of their biggest achievements. At 27 km long, it is the largest particle accelerator on the planet, and also the largest-ever human-made machine.
The LHC is made up mostly of superconducting cryomagnets of different lengths between 6 and 15 metres and uses hugely powerful electric and magnetic fields to accelerate, guide and then smash particles together for important scientific study. Each consists of a container tube, called the Vacuum Vessel, and the highly delicate inner equipment with the cryomagnets, called the Cold Mass.
The Applus+ Laboratories engineering team was tasked to develop bespoke tooling for the assembly (and disassembly) of the High Luminosity LHC (HL-LHC) cryomagnets. This was not merely a case of putting the Cold Mass together. CERN required tooling versatile enough to dissemble the ‘old generation’ cryomagnets already mounted, and replace them with ‘new generation’ cryomagnets, which were not identical in form to the old.
The biggest challenge would be finding a suitable way to manoeuver the Cold Mass, which in the case of the HL-LHC project can weigh up to 24Tn, in and out of the Vacuum Vessel. We were asked to provide a system that didn’t use wheels or rollers, as these could make it difficult to keep the cryomagnets in exactly the right positions inside the Vacuum Vessel.
What’s more, as the LHC’s cryomagnets vary in size from one another, a completely new system would need to be invented which would be adaptable to all the different sizes and configurations.
Adding even more gravity to the task at hand, we were asked to create two versions of the same tooling – one for CERN and one for FERMILAB, in the USA.
Our experts used their knowledge of materials, FEM analysis and electrical and mechanical design to create an innovative guiding system, as well as a synchronized lifting system. The final product was made up of:
- An assembly table to equip the Cold Mass
- An adjustable table that can be configured to support different-sized Vacuum Vessels
- A synchronized lifting system to lift and hold the Cold Mass in place
- Winches to pull the Cold Mass in and out of the vessel
- Extension rails, working in conjunction with low-friction Vesconite pads, to safely and efficiently guide the Cold Mass in and out
The result of innovative design, testing expertise and apt engineering
Thanks to our testing expertise and full-scale engineering facilities, we were able to test the structural systems to validate the results of the FEM simulation carried out in the design stage. Our resources also enabled us to conduct validation testing of the Vesconite pads, a key element for the assembly process.
The tooling can be configured to assemble 10 different variants of cryomagnets, making it the ideal solution for the LHC’s different-sized magnets. What’s more, it can be programmed to insert and remove the Cold Mass at two different speeds if required, 100 and 1000 millimetres per minute. Ergonomics and usability were considered throughout the design process, to ensure we delivered an effective, turnkey product.
Mike Struik, Project Engineer at CERN: ‘I was very satisfied with the quality and versatility of the tooling developed by the experts at Applus+, as well as how easy they were to collaborate with.’