LHC Luminosity Upgrade: Protecting Insertion Region Magnets from Collision Debris

The Large Hadron Collider built at CERN now enters a starting-up phase where the present design luminosity up to 1034 cm-2 s-1 will be reached after the running in phase. A possible upgrading of the machine to luminosity up to 10^35 cm^-2 s^-1 requires a new insertion region design, and will be implemented in essentially two phases. The energy from collision debris is deposited in the insertion regions and in particular in the superconducting magnet coils with a possible risk of quench. We describe here how to protect the interaction region magnets against this irradiation to keep the energy deposition below critical values estimated for safe operation. The constraint is to keep the absorber size as small as possible to leave most of the magnet aperture available for the beam. This can be done by choosing a suitable material and design minimizing the load on the cryogenic system. Here we will describe design proposals for the phase I upgrade lay-out, i.e. luminosity up to 2.5 10^34 cm^-2 s^-1.