Cleaning Performance with 11T Dipoles and Local Dispersion Suppressor Collimation at the LHC

The limiting location of the present LHC machine in terms of losses on cold magnets are the dispersion suppressors downstream of the betatron collimation insertion (IR7). These losses are dominated by off-energy protons that have by-passed the upstream secondary collimation system but are lost where the dispersion starts to rise. A solution under consideration for intercepting these losses is the addition of new collimators in the dispersive area. This paper discusses first a proposition for the new layout in the DS, where space is made for the new collimators by replacing an existing dipole by shorter and stronger magnets. Furthermore, simulations with SixTrack are presented, which quantify the gain in cleaning from the new collimators.