WEOAG  —  Circular Colliders   (25-Jun-08   10:00—10:40)

Chair: S. Tazzari, INFN-Roma II, Roma

Paper Title Page
WEOAG01 Prospects for a Large Hadron Electron Collider (LHeC) at the LHC 1903
 
  • M. Klein
    Liverpool University, Science Faculty, Liverpool
  • H. Aksakal
    N. U, Nigde
  • F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, J. M. Jowett, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, F. Zimmermann, A. de Roeck
    CERN, Geneva
  • S. Chattopadhyay, J. B. Dainton
    Cockcroft Institute, Warrington, Cheshire
  • A. K. Ciftci
    Ankara University, Faculty of Sciences, Tandogan/Ankara
  • A. Eide
    EPFL, Lausanne
  • B. J. Holzer
    DESY, Hamburg
  • P. Newman
    Birmingham University, Birmingham
  • E. Perez
    CEA, Gif-sur-Yvette
  • S. Sultansoy
    TOBB ETU, Ankara
  • A. Vivoli
    LAL, Orsay
  • F. J. Willeke
    BNL, Upton, New York
 
  The LHeC collides a lepton beam with one of the intense, LHC, hadron beams. It achieves both e± interactions with quarks at the terascale, at eq masses in excess of 1 TeV, with a luminosity of about 1033 cm-2 s-1, and it also enables a sub-femtoscopic probe of hadronic matter at unprecedented chromodynamic energy density, at Bjorken-x values down to 10-6 in the deep inelastic scattering domain. The LHeC combines the LHC infrastructure with recent advances in radio-frequency, in linear acceleration and in other associated technologies, to enable two proposals for TeV ep collisions: a "ring-ring" option in which 7 TeV protons (and ions) collide with about 70 GeV electrons/positrons in a storage ring in the LHC tunnel and a "linac-ring" option based on an independent superconducting linear accelerator enabling single-pass collisions of electrons and positrons of up to about 140 GeV with an LHC hadron beam. Both options will be presented and compared. Steps are outlined for completing a Conceptual Design Review of the accelerator complex, beam delivery, luminosity, physics and implications for experiment, following declared support by ECFA and by CERN for a CDR.  
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WEOAG02 Measurements of Heavy Ion Beam Losses from Collimation 1906
 
  • R. Bruce, R. W. Assmann, G. Bellodi, C. Bracco, H.-H. Braun, S. S. Gilardoni, E. B. Holzer, J. M. Jowett, S. Redaelli, Th. Weiler, C. Zamantzas
    CERN, Geneva
 
  The collimation efficiency for Pb82+ ion beams in the LHC is predicted to be much lower than for protons. Nuclear fragmentation and electromagnetic dissociation in the primary collimators create fragments with a wide range of Z/A ratios, which are not intercepted by the secondary collimators but lost where the dispersion has grown sufficiently large. In this article we present measurements of loss patterns caused by a prototype LHC collimator in the CERN SPS. The loss maps show a qualitative difference between Pb82+ ions and protons, with the maximum loss rate observed at different places in the ring. This behaviour was predicted by simulations and provides a valuable benchmark of the simulations done for the LHC.  
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