Speaker
Description
CERN’s next generation hadron collider, the Future Circular Collider (FCC-hh) will achieve an increase in center-of-mass collision energies of a factor seven when compared to the Large Hadron Collider (LHC), reaching 100 TeV. To handle the higher energy levels of the orbiting particle beam and shield the magnet cold bore from the synchrotron radiation produced by the accelerated charged particles, a new beam screen design is necessary. Due to its proximity to the beam, the beam screen must present a low surface impedance to ensure beam stability and minimize the heat produced by the image currents induced by the beam in the beam screen.
Delaminated Rare Earth-Ba2Cu3Ox (REBCO) High Temperature Superconductors (HTS) Coated Conductors (CC) are proposed as a coating solution for the FCC beam screen, as a means to achieve the necessary low surface impedance. However, due to the trapped fields in HTS exposed to external magnetic fields, a full REBCO coating would decrease the field quality in the beam surroundings, once again threatening beam stability. To avoid this, a hybrid coating composed of alternated longitudinal segments of REBCO and Cu is proposed.
In this talk, we present our research achievements over these years, where we have worked towards understanding the high-field microwave response of REBCO CCs and we have demonstrated its better-than Cu surface resistance up to fields of 16T. We analyze the behavior of the Beam Screen with the hybrid coating when exposed to the bending and focusing magnets of the FCC by the means of Finite Elements Method numerical computation, focusing on the effect of different coating topologies in the field homogeneity inside the vacuum chamber. We will also present our developments on a coating technique using CCs to cover flat and curved surfaces (such as those needed for the beam-screen chamber of the FCC-hh).
