• T. Argyropoulos, T. Bohl, T.P.R. Linnecar, E.N. Shaposhnikova, J. Tuckmantel
  CERN, Geneva

Controlled longitudinal emittance blow-up together with a fourth harmonic RF system are two techniques that are being used in the SPS in order to stabilize the beam before injecting into the LHC. The emittance blow-up has been achieved by introducing a band-limited phase noise during acceleration. Measured variations of the final emittance along the batch can be explained by the modification of the synchrotron frequency distribution due to the effect of beam loading in a double harmonic RF system.