| Paper |
Title |
Page |
| WEODA01 |
Observations of Beam-beam Effects at High Intensities in the LHC |
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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| WEODA02 |
Collimation Studies with Hollow Electron Beams |
1939 |
| |
- G. Stancari, G. Annala, T.R. Johnson, G.W. Saewert, V.D. Shiltsev, D.A. Still, A. Valishev
Fermilab, Batavia, USA
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Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP).
Recent experimental studies at the Tevatron collider have shown that magnetically confined hollow electron beams can act as a new kind of collimator for high-intensity beams in storage rings. In a hollow electron beam collimator, electrons enclose the circulating beam. Their electric charge kicks halo particles transversely. If their distribution is axially symmetric, the beam core is unaffected. This device is complementary to conventional two-stage collimation systems: the electron beam can be placed arbitrarily close to the circulating beam; and particle removal is smooth, so that the device is a diffusion enhancer rather than a hard aperture limitation. The concept was tested in the Tevatron collider using a hollow electron gun installed in one of the existing electron lenses. We describe some of the technical aspects of hollow-beam scraping and the results of recent measurements.
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Slides WEODA02 [9.049 MB]
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| WEODA03 |
Design Concepts for the Large Hadron Electron Collider |
1942 |
| |
- M. Klein
The University of Liverpool, Liverpool, United Kingdom
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A report is presented on the design concepts for a high luminosity electron-nucleon collider of 1.3 TeV centre of mass energy, realized with the addition of a 60 GeV electron ring or linear accelerator to the existing proton and ion LHC beam facility, comprising machine magnets, optics, interaction region, cryogenics, rf, civil engineering and further components of the LHeC. The report on behalf of the LHeC study team is a summary of the 2011 LHeC CDR and feedback received from an international review panel.
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Slides WEODA03 [9.780 MB]
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