The superconducting magnets in the Dispersion suppressors at the end of the straight sections are the main location for beam losses in cold magnets in the LHC. For the FCC this poses a problem due to the much higher beam energies. The losses in these regions mainly come from off-momentum particles due to proton-proton collisions in the experimental areas, and single-diffractive effects from interaction with primary collimators in the cleaning insertions. To protect those magnets and to ensure safe operation of the machine, a new protection system is necessary.
The requirements for the beam optics have been assessed and suitable space has been integrated in the current lattice to allow the placement of the protection system.
A collimation system has been designed and optimized with respect to energy deposition in the magnets due to particle showers from the collimators.
Tracking simulations, using the MERLIN tracking code, have been done to ensure that the new system is effective in catching the off-momentum losses. Shower simulations have been done using the FLUKA code to assess the energy deposition in the downstream magnets and compare it to quench limits.