Operation of the LHC at High luminosity and High stored energy

In 2011 the operation of the Large Hadron Collider LHC entered its first year of high luminosity production at a beam energy of 3.5 TeV. In the first months of 2011 the number of bunches was progressively increased to 1380, followed by a reduction of the transverse emittance, an increase of the bunch population and a reduction of the betatron function at the collision points. The performance improvements steps that were accumulated in 2011 eventually brought the peak luminosity to 3.6 × 1033cm−2s−1. The integrated luminosity delivered to each of the high luminosity experiments amounted to 5.6 fb−1, a factor of 5 above the initial target defined in 2010. The operational experience with high intensity and luminosity at the LHC will be presented, together with the issues that had to be tackled on the road to high intensity and luminosity.