Measuring Beta Functions and Dispersion in the Early LHC

Achieving nominal beam conditions in the LHC requires a small beta beating and a small dispersion mismatch. We compare the linear optics errors expected from linear and nonlinear magnetic field imperfections and magnet mis-alignments with the required values. The measurement procedures are simulated in a machine with collimators, realistic aperture restrictions, and different bunch intensities, in order to infer the expected measurement accuracies for beta beating and dispersion. Consequences for possibly required beam-based correction tools are discussed.