| Paper |
Title |
Page |
| TUPAN048 |
Beam-beam Effects With an External Noise in LHC
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1496 |
| |
- K. Ohmi
KEK, Ibaraki
- R. Calaga
BNL, Upton, Long Island, New York
- W. Hofle, R. Tomas, F. Zimmermann
CERN, Geneva
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Proton beam do not have any damping mechanism for an incoherent betatron motion. A noise, which kicks beam particles in the transverse plane, gives a coherent betatron amplitude. Nonlinear force due to the beam-beam interactions causes a decoherence for the betatron motion with keeping an amplitude of each beam particle, with the result that an emittance growth arises. We focus fast transverse turn by turn noises caused by a bunch by bunch feedback system and a cavity phase zitter in crab collision.
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| FRPMN076 |
Nominal LHC Beam Instability Observations in the CERN Proton Synchrotron
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4222 |
| |
- 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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