• L. Sermeus, M.J. Barnes, T. Fowler
  CERN, Geneva

A five-turn continuous extraction is currently used to transfer the proton beam from the CERN PS to the SPS. This extraction uses an electrostatic septum to cut the filament beam into five slices, causing losses of about 15 %. These losses would be an even greater drawback when the beam intensity is further increased for the CERN Neutrinos to Gran Sasso facility. To overcome this, a Multi-Turn Extraction (MTE) has been implemented, in which the beam is separated, prior to extraction, into a central beam core and four islands. Each beamlet is extracted using a set of kickers and a magnetic septum. For the kickers two new pulse generators have been built, each containing a lumped element Pulse Forming Network (PFN) of 12.5 Ohms, 80 kV and 10.5 μs. For cost reasons existing 15 Ω transmission line kicker magnets are reused. The PFN characteristic impedance deliberately mismatches that of the magnets to allow a higher maximum kick. The PFN design has been optimised such that undesirable side-effects of the impedance mismatch on kick rise-time and flat-top remain within acceptable limits. The kicker systems put in place for the current first phase of MTE are presented.

• J. Borburgh, B. Balhan, M.J. Barnes, T. Fowler, M. Hourican, M. Palm, A. Prost, L. Sermeus, T. Stadlbauer
  CERN, Geneva
• F. Hinterschuster
  TU Vienna, Wien
• T. Kramer
  EBG MedAustron, Wr. Neustadt

The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and different types of ions for cancer therapy and research. Ten different types of bumpers, septa and kickers will be used in the low energy beam transfer line, the synchrotron and the high energy extraction lines. They are presently being designed in collaboration with CERN. Both 2D and 3D finite element simulations have been carried out to verify and optimize the field strength and homogeneity for each type of magnet and, where applicable, the transient field response. The detailed designs for the injection and dump bumpers, the magnetic septa and the fast chopper dipoles are presented. A novel design for the electrostatic septa is outlined.

• M. Giovannozzi, E. Benedetto, A. Blas, T. Bohl, S. Cettour Cave, K. Cornelis, D.G. Cotte, H. Damerau, M. Delrieux, J. Fleuret, F. Follin, T. Fowler, P. Freyermuth, H. Genoud, S.S. Gilardoni, S. Hancock, O. Hans, Y. Le Borgne, D. Manglunki, E. Matli, G. Metral, E. Métral, M. Newman, L. Pereira, F.C. Peters, Y. Riva, F. Roncarolo, L. Sermeus, R.R. Steerenberg, B. Vandorpe, J. Wenninger
  CERN, Geneva
• F. Franchi
  ESRF, Grenoble

Following the analysis of the results obtained during the first year of beam commissioning of the CERN multi-turn extraction, a number of changes have been introduced in the beam manipulations performed in the CERN Proton Synchrotron. This includes a different control of the linear chromaticity, the setting of the non-linear magnets used to split the beam, and the longitudinal structure in the PS. The results obtained during the 2009 run are presented and discussed in detail, including the beam performance in both the PS and the SPS, as well as the optics measurements in the transfer line between the two circular machines.

Slides