Author: Langner, A.
Paper Title Page
TUPFI039 Optics Performance of the LHC During the 2012 Run 1433
 
  • 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
 
  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.  
 
TUPFI041 Operating the LHC Off-momentum for p-Pb Collisions 1439
 
  • 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
 
  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.