Optimization of the LHC lattice and chromaticity

The p-p collider (LHC) that could be built in the LEP tunnel above the LEP machine requires superconducting magnets to maximize the beam energy. For a given magnetic field level, an increase of the standard FODO cell length allows a further increase of the maximum energy, at the expense of the beam dynamics. In a previous study two cell lengths have been considered assuming that the LHC and LEP quadrupoles are superposed. Further technical studies have shown that this requirement may be relaxed. This paper presents an optimization of the cell length with respect to maximum energy, dynamic aperture, perturbation of the Courant and Snyder invariants, tune shifts with amplitude and momentum. As previously, only the sextupole components (both systematic and random) in the dipole magnets have been taken into account