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Franchetti, G.

Paper Title Page
TUZAAB02 Recent Developments in Understanding Beam Loss in High-intensity Synchrotrons 794
  • G. Franchetti
    GSI, Darmstadt
  Recent advances in understanding space-charge-induced beam loss and emittance growth have been achieved, which allow quantitative predictions for large number of turns (exceeding 105). In this talk we review the theoretical model of trapping by space charge effects, simulation results and experimental findings obtained at the CERN Proton Synchrotron and the heavy ion synchrotron SIS18 at GSI. The impact of these effects on the beam loss budget/beam loss control for heavy ion beams in the SIS100 synchrotron in the FAIR project will be presented. Applications of these mechanisms to e-cloud space charge interaction with hadron beams in the LHC will be also be discussed.  
slides icon Slides  
THPAN016 Improving the SIS18 Performance by use of the Orbit Response Method 3256
  • A. S. Parfenova, G. Franchetti, I. Hofmann, C. Omet
    GSI, Darmstadt
  • S.-Y. Lee
    IUCF, Bloomington, Indiana
  The SIS18 will be used as a booster for the new FAIR facility SIS100. A well-controlled linear optics of the SIS18 is necessary for further optimisation studies of nonlinear dynamics, resonance induced beam loss, dynamic aperture and nonlinear error measurements. The analysis of the orbit response matrix (ORM) is a powerful tool to calibrate the linear lattice models. We present results of several measurements on the SIS18 using the ORM and discuss the achieved improvement of the SIS18 performance.  
THPAN017 Scaling Laws for Space Charge Driven Resonances 3259
  • I. Hofmann, G. Franchetti
    GSI, Darmstadt
  Intrinsic fourth order space charge resonances may occur in linear as well as circular accelerators. The difference resonance ("emittance exchange" or "Montague" resonance) and the fourth order structure resonance lead to emittance variations depending on the strength of space charge, the crossing rate and the lattice. We present scaling laws for the Montague coupling resonance and for the fourth order structure resonance in terms of simple power law expressions that allow a straightforward application in design of accelerators subject to these mechanism.  
THPAN030 Transverse Self-Consistent Modeling of a 3D Bunch in SIS100 with MICROMAP 3292
  • C. Benedetti, S. Rambaldi, G. Turchetti
    Bologna University, Bologna
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  Funding: EU-DESIGN STUDY (contract 515873 - DIRACsecondary-Beams)

We present the upgrade of the MICROMAP beam dynamics simulation library to include a 2 1/2 D space charge modeling of a 3D bunch using local slices in z. We discuss the parallelization technique, the performances, several tests and comparison with existing well-established analytical/numerical results in order to validate the code. An application to the SIS100 synchrotron of the FAIR project at GSI is outlined.

THPAN074 Space-Charge Compensation Options for the LHC Injector Complex 3390
  • F. Zimmermann, M. Aiba, M. Chanel, U. Dorda, R. Garoby, J.-P. Koutchouk, M. Martini, E. Metral, Y. Papaphilippou, W. Scandale
    CERN, Geneva
  • G. Franchetti
    GSI, Darmstadt
  • V. D. Shiltsev
    Fermilab, Batavia, Illinois
  Space-charge effects have been identified as the most serious intensity limitation in the CERN PS and PS booster, on the way towards ultimate LHC performance and beyond. We here explore the application of several previously proposed space-compensation methods to the two LHC pre-injector rings, for each scheme discussing its potential benefit, ease of implementation, beam-dynamics risk, and the R&D programme required. The methods considered include tune shift and resonance compensation via octupoles, nonlinear chromaticity, or electron lenses, and beam neutralization by an electron cloud, plasma or negative ions.  
THPAN075 Modeling Incoherent Electron Cloud Effects 3393
  • F. Zimmermann, E. Benedetto, G. Rumolo, D. Schulte, R. Tomas
    CERN, Geneva
  • W. Fischer
    BNL, Upton, Long Island, New York
  • G. Franchetti
    GSI, Darmstadt
  • K. Ohmi
    KEK, Ibaraki
  • M. T.F. Pivi, T. O. Raubenheimer
    SLAC, Menlo Park, California
  • K. G. Sonnad, J.-L. Vay
    LBNL, Berkeley, California
  Incoherent effects driven by an electron cloud could seriously limit the beam lifetime in proton storage rings or blow up the vertical emittance in positron ones. Different approaches to modeling these effects each have their own merits and drawbacks. We compare the simulation results and computing time requirements from a number of dedicated codes under development over the last years, and describe the respective approximations for the beam-electron cloud interaction, the accelerator structure, and the optical lattice, made in each of these codes. Examples considered include the LHC, CERN SPS, RHIC, and the ILC damping ring. Tentative conclusions are drawn and a strategy for further codes development is outlined.