Investigations of the Parameter Space for the LHC Luminosity Upgrade

Increasing the LHC luminosity by a factor of ten is a major challenge, especially for the beam-beam long-range interactions and even more for the magnet technology and insertion layout. To help identifying consistent solutions in this multi-dimensional constrained space, a parametric model of an LHC insertion was prepared, based on the present LHC layout, i.e. ?quadrupole first? and small crossing angle. The model deals with the layout, beam optics, beam-beam effect, superconductor margin and peak heat deposition in the coils. The approach is simplified to obtain a large gain in the optimization time. This study puts in evidence, as critical for the luminosity upgrade, the following actions: enlarging significantly the quadrupole aperture, moving the insertion towards the interaction point, using the highest available critical field superconductors and complementing the insertion with an early separation scheme. The luminosity reach can then be extended to 2×1035 cm-2s-1 while 1×1035 can be obtained with significantly reduced requirements (lower beam currents, simpler RF system?).