Field quality in low-β superconducting quadrupoles and impact on the beam dynamics for the Large Hadron Collider upgrade

A possible scenario for the luminosity upgrade of the Large Hadron Collider is based on large aperture quadrupoles to lower β^* in the interaction regions. Here we analyze the measurements relative to the field quality of the RHIC and LHC superconducting quadrupoles to find out the dependence of field errors on the size of the magnet aperture. Data are interpreted in the framework of a Monte Carlo analysis giving the reproducibility in the coil positioning reached in each production. We show that this precision is likely to be independent of the magnet aperture. Using this result, we can carry out an estimate of the impact of the field quality on the beam dynamics for the collision optics.