Superconductivity occurs at the very low temperatures that are common at the LHC, the world's largest cryogenic system and one of the coldest places in the Universe! Cooling turns out to be one of the major challenges for future particle colliders that include superconducting systems. 

Cryogenics are important for both a future lepton and hadron circular collider like those explored by the FCC Study. The FCC-hh presents unique challenges for cryogenic technologies because for the first time, it will be based on 16 T superconducting magnets with Nb₃Sn windings operating at a temperature below 2 K in order to minimise the amount of superconducting material

The FCC collaboration is studying new technologies for cooling from room temperature down to 1 Kelvin with unprecedented efficiency in order to keep energy consumption as low as reasonably possible. Cryogenics and cooling systems can also find applications in areas beyond particle physics, ranging from the food processing industry to space-transport and satellites, medical devices, natural gas production, storage and transport, and also cooling appliances in every home! 

The compressor unit of the 4.5 K refrigerator at Point 6. The unit provides 18 kW cooling capacity. There are eight of these units in the complete system (Image: CERN)

The cryogenic layout of the FCC-hh machines is a direct consequence of the site constraints and thus closely linked to the ongoing territorial investigations as part of the FCC Feasibility Study. 

Key focus of ongoing R&D:

• Energy-efficient refrigeration cycles

• Highly reliable and cost-effective turbocompressors

• Non-conventional (e.g. magnetic) refrigeration processes

• Non-linear dynamic process simulation