• O. Boine-Frankenheim, O. Chorniy
  GSI, Darmstadt

The conservation of the longitudinal beam quality through the SIS-18/100 synchrotron chain is of major importance for the FAIR accelerator project as well as for the SIS-18 upgrade. The generation of a short, intense heavy ion bunch at the end of the machine cycle defines a tight budget for the tolerable longitudinal emittance growth. Potential sources of bunch quality degradation are intensity effects and non-adiabatic rf ramps during the rf capture in SIS-18 and during the barrier bucket pre-compression in SIS-100. The time spend on rf manipulations has to be as small as possible in order to maximize the repetition rate. We report about theoretical and experimental studies in SIS-18 of optimized voltage ramps for rf capture into single and double rf buckets, including space charge and beam-loading effects. Further we show that longitudinal space charge can improve the efficiency of rf manipulations. As an example we present an optimized barrier bucket pre-compression scheme for SIS-100.

• G. Franchetti, W.B. Bayer, F. Becker, O. Chorniy, P. Forck, T. Giacomini, I. Hofmann, M.M. Kirk, T.S. Mohite, C. Omet, A.S. Parfenova, P. Schütt
  GSI, Darmstadt

The prediction of beam loss for long term storage of a high intensity beam is a challenging task essential for the SIS100 design. On this ground an experimental campaign using a high intensity beam has been performed at GSI on the SIS18 synchrotron with the purpose of extending a previous benchmarking experiment made at the CERN-PS in the years 2002-2003. We report here the results of this experimental campaign and the benchmarking with the simulation predictions.