As part of an international collaboration, CERN has recently published a Conceptual Design Review of the Future Circular Collider (FCC), a proposed particle accelerator to succeed the LHC. Under the options considered, a proto-proton accelerator with collision energies up to 100 TeV, would require approximately 4’500 Nb3Sn superconducting dipole magnets operating at 16 T fields, installed in a new tunnel of about 100 km circumference. A proposed variant, as a possible first step towards the FCC, is the incorporation of these magnets in the existing LHC tunnel infrastructure. This will provide a proton-proton collider with about twice the collision energy of the LHC, the so-called High Energy LHC (HE-LHC). The 16 T dipoles, which are considerably larger and heavier than the 8.33 T LHC dipoles, require compact cryostats to keep the overall dimensions comparable with the size of the LHC tunnel.
In this paper, we report on the design and integration work on the baseline 16T cosine-theta design dipole magnets within their cryostats. We present here, possible design options departing from the well-established solution of the LHC cryostats, including mechanical and thermal design considerations on the cryostat. We also explore the electromagnetic and mechanical coupling between the magnet and the vacuum vessel, in the case of a stray field in the cryostat space, as would be required to reduce the volume of the cold mass.