CERN, Geneva
The cryogenic system of the Large Hadron Collider (LHC) is the largest in the world in terms of refrigeration capacity with about 140 kW at 4.5 K, distributed superfluid helium with 25 km of superconducting magnets below 2 K and cryogen inventory above 120 tons of helium. The challenges involved in the design, construction, installation, commissioning as well as the first operating experience will be addressed. Identified weak points and actions taken will be reported with observed impact on operation. Perspectives for LHC will be presented and general considerations for future large cryogenic systems will be briefly proposed.
CERN, Geneva
In the LHC, a large number of superconducting magnets are powered remotely by 5 superconducting links at distances of 70 up to 540 m. This innovation allowed to choose more convenient locations for installing the electrical feedboxes and their related equipment. The consolidations performed after the first commissioning campaign and the operational experience with the superconducting links over a period of several months are presented. Based on the successful application of superconducting links in the LHC, such devices can be envisaged for powering future accelerator magnets. Several possible cryogenic configurations for future superconducting links are presented with their respective figures of merit from the cryogenic and practical implementation point of view.