The LHC RF–2011 and beyond

The RF system performance in 2011 is presented, with statistics on the High Level faults. The few debunching events are explained. The changes to the RF parameters with respect to the previous run are reviewed . The survival of the RF to a klystron trip is studied: when half nominal current was reached in June 2011, a klystron trip was linked to the beam dump to prevent the beam circulating in the idling cavity from damaging the cavity and RF load. The action of the longitudinal blow - up on the beam current spectrum (or average longitudinal bunch profile) is shown for both protons and lead ions . The operation at 4 TeV and above is considered. Finally, a proposal for 25 ns operation and nominal beam current is presented.