Author: Bellodi, G.
Paper Title Page
TUPZ007 First Ion Collimation Commissioning Results at the LHC 1813
 
  • G. Bellodi, R.W. Assmann, R. Bruce, M. Cauchi, J.M. Jowett, G. Valentino, D. Wollmann
    CERN, Geneva, Switzerland
 
  First commissioning of the LHC Pb ion beams to 1.38 A TeV energy was successfully achieved in November 2010. Ion collimation has been predicted to be less efficient than for protons at the LHC, because of the complexity of the physical processes involved: nuclear fragmentation and electromagnetic dissociation in the primary collimators creating fragments with a wide range of Z/A ratios, that are not intercepted by the secondary collimators but lost in the dispersion suppressor sections of the ring. In this article we present first comparisons of measured loss maps with theoretical predictions from simulation runs with the ICOSIM code. An extrapolation to define the ultimate intensity limit for Pb beams is attempted. The scope of possible improvements in collimation efficiency coming from the installation of new collimators in the cold dispersion suppressors and combined betatron and momentum cleaning is also explored.  
 
WEPS022 Ions for LHC: Performance of the Injector Chain 2529
 
  • D. Manglunki, M. E. Angoletta, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, M. Chanel, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, E. Métral, S. Pasinelli, M. Schokker, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
    CERN, Geneva, Switzerland
 
  The first LHC Pb ion run took place at 1.38 A TeV/c per beam in autumn 2010. After a short period of running-in, the injector chain was able to fill the collider with up to 137 bunches per ring, with an intensity of 108 Pb ions/bunch, about 50% higher than the design value. This yielded a luminosity of 3E25 Hz/cm2, allowing the experiments to accumulate just under 10 inverse microbarn each during the four week run. We review the performance of the individual links of the injector chain, and address the main issues limiting the LHC luminosity, in view of reaching 1026 Hz/cm2 in 2011, and substantially beyond when the LHC energy increases after the long shutdown in 2013-14.