Paper |
Title |
Page |
TUPFI039 |
Optics Performance of the LHC During the 2012 Run |
1433 |
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- P. Skowroński, T. Bach, M. Giovannozzi, A. Langner, Y.I. Levinsen, E.H. Maclean, T. Persson, S. Redaelli, T. Risselada, M. Solfaroli Camillocci, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
- M.J. McAteer
The University of Texas at Austin, Austin, USA
- R. Miyamoto
ESS, Lund, Sweden
- T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
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During 2012 the LHC was operating at 4TeV with beta star at ATLAS and CMS interaction points of 0.6m. During dedicated machine studies the nominal LHC optics was also setup with beta star of 0.4m. A huge effort was put into the optics commissioning leading to a record low peak beta-beating of around 7%. We describe the correction procedures and discuss the measurement results.
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TUPFI041 |
Operating the LHC Off-momentum for p-Pb Collisions |
1439 |
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- R. Versteegen, R. Bruce, J.M. Jowett, A. Langner, Y.I. Levinsen, E.H. Maclean, M.J. McAteer, T. Persson, S. Redaelli, B. Salvachua, P. Skowroński, M. Solfaroli Camillocci, R. Tomás, G. Valentino, J. Wenninger
CERN, Geneva, Switzerland
- E.H. Maclean
JAI, Oxford, United Kingdom
- M.J. McAteer
The University of Texas at Austin, Austin, USA
- T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
- G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta
- S.M. White
BNL, Upton, Long Island, New York, USA
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The first high-luminosity p-Pb run at the LHC took place in January-February 2013 at an energy of 4 Z TeV per beam. The RF frequency difference of proton and Pb is about 60 Hz for equal magnetic rigidities, which means that beams move slightly to off-momentum, non-central, orbits during physics when frequencies are locked together. The resulting optical perturbations ("beta-beating") restrict the available aperture and required a special correction. This was also the first operation of the LHC with low beta in all four experiments and required a specific collimation set up. Predictions from offline calculations of beta-beating correction are compared with measurements during the optics commissioning and collimator set up.
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