Paper |
Title |
Other Keywords |
Page |
TUPZ029 |
Observation of Coherent Beam-beam Effects in the LHC |
simulation, emittance, damping, collider |
1870 |
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- X. Buffat
EPFL, Lausanne, Switzerland
- R. Calaga, S.M. White
BNL, Upton, Long Island, New York, USA
- R. Giachino, W. Herr, G. Papotti, T. Pieloni
CERN, Geneva, Switzerland
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Early collisions in the LHC with a very limited number of bunches with high intensities indicated the presence of coherent beam-beam driven oscillations. Here we discuss the experimental results and compare with the expectations.
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WEODA01 |
Observations of Beam-beam Effects at High Intensities in the LHC |
luminosity, emittance, dynamic-aperture, brightness |
1936 |
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- W. Herr, R. Alemany-Fernandez, R. Giachino, G. Papotti, T. Pieloni
CERN, Geneva, Switzerland
- R. Calaga
BNL, Upton, Long Island, New York, USA
- E. Laface
ESS, Lund, Sweden
- M. Schaumann
RWTH, Aachen, Germany
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First observations with colliding beams in the LHC with bunch intensities close to nominal and above are reported. In 2010 the LHC initially operated with few bunches spaced around the circumference. Beam-beam tune shifts exceeding significantly the design value have been observed. In a later stage crossing angles were introduced around the experiments to allow the collisions of bunch trains. We report the first experience with head-on as well as long range interactions of high intensity bunches and discuss the possible performance reach.
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Slides WEODA01 [0.409 MB]
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WEPC081 |
Beam-Beam Induced Orbit Effects at LHC |
luminosity, simulation, closed-orbit, collider |
2208 |
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- M. Schaumann, R. Alemany-Fernandez
CERN, Geneva, Switzerland
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For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are presented in this paper.
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