Speaker
Description
CERN has launched the FCC Innovation Study R&D program that will support the feasibility study for the FCC-hh, a new circular hadron collider with 100 km circumference where 16T superconducting magnets will steer proton bunches producing center-of-mass collision energies of 100TeV. Part of this R&D initiative is to rethink the design of the beam-screen chamber, a stainless steel pipe necessary to thermally shield the cold bores of the superconducting dipole magnets from the synchrotron radiation emitted by the accelerated protons. The charged particles will induce 1 GHz RF image currents into the pipes walls, whose wake fields endanger the beam stability. To counteract this effect, the interior of a beam-screen chamber is coated with a highly conductive material. Within a consortium formed in 2017 between ALBA synchrotron, the institute of high energy physics, the polytechnic university of Barcelona, the institute of material science of Barcelona and CERN, we have demonstrated the benefit of replacing the conventional beam-screen coating material, Cu, with REBa2Cu3O7-x (RE = rare earth) Coated Conductors (CCs) in order to increase the beam stability margin.
In this talk, we present the consortium achievements over these years [1], where we have worked towards understanding the high-field microwave response of CCs, and we have developed hybrid CC / Cu geometries that limit trapped field and present lower than Cu surface resistances. Our findings have placed CC’s technology as a solid candidate to replace Cu as the low surface-impedance coating of the FCC-hh beam-screen. We will also present how our research in CC’s microwave response under the extreme conditions found in the FCC [2], together with the large-area CC surface coating technology being developed within the consortium, benefits other areas of high-energy physics such as Axion detection.
[1] T. Puig et al, Supercond. Sci. Technol. 32 (2019)
[2] A. Romanov, et al. Scientific reports 10 (2020)
