Paper |
Title |
Page |
THPAN075 |
Modeling Incoherent Electron Cloud Effects
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3393 |
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- 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
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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.
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FRPMN038 |
Simulation of Synchro-betatron Sideband Instability caused by Electron Clouds at KEKB
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4033 |
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- J. W. Flanagan
- E. Benedetto
CERN, Geneva
- J. Hyunchang
POSTECH, Pohang, Kyungbuk
- K. Ohmi
KEK, Ibaraki
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Electron cloud causes a fast head-tail instability above a threshold density. Experiments at KEKB showed synchro-betatron sideband, which indicates the head-tail instability. The sideband appears near νy+kνs, where 1<k<2, that differs from ordinary instability seen near νy-νs. We investigate the origin of the sideband using a computer simulation.
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FRPMN076 |
Nominal LHC Beam Instability Observations in the CERN Proton Synchrotron
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4222 |
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- R. R. Steerenberg
- G. Arduini, E. Benedetto, A. Blas, W. Hofle, E. Metral, M. Morvillo, C. Rossi, G. Rumolo
CERN, Geneva
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The nominal LHC beam has been produced successfully in the CERN Proton Synchrotron since 2003. However, after having restarted the CERN PS in spring 2006, the LHC beam was set-up and observed to be unstable on the 26 GeV/c extraction flat top. An intensive measurement campaign was made to understand the instability and to trace its source. This paper presents the observations, possible explanations and the necessary measures to be taken in order to avoid this instability in the future.
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