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Schmidt, R.

Paper Title Page
MOPLS005 A Staged Approach to LHC Commissioning 538
 
  • R. Bailey, O.S. Brüning, P. Collier, M. Lamont, R.J. Lauckner, R. Schmidt
    CERN, Geneva
 
  After a brief reminder of the performance goals of the LHC, the overall strategy proposed for commissioning the machine with protons is presented. A thorough commissioning of the LHC hardware systems, presently ongoing, will lead into a staged approach for the first two years of operation with the beam, allowing both the complexity of the machine operation and the destructive power of the high intensity beams to be introduced in a controlled, incremental manner. The demands on the annual machine schedule are discussed, including the need to incorporate dedicated running for ions and proton-proton total cross section measurements. An important pre-commissioning milestone is the injection of the beam into a sector of the partially completed LHC; the motivation and tests planned are briefly summarised.  
TUPLS126 Interaction of the CERN Large Hadron Collider (LHC) Beam with Carbon Collimators 1798
 
  • N.A. Tahir, D. Hoffmann
    GSI, Darmstadt
  • Y. Kadi, R. Schmidt
    CERN, Geneva
  • R. Piriz
    Universidad de Castilla-La Mancha, Ciudad Real
  • A. Shutov
    IPCP, Chernogolovka, Moscow region
 
  The LHC will operate at 7 TeV with a luminosity of 1034 cm-2s-1. Each beam will have 2808 bunches, with nominal intensity per bunch of 1.1x1011 protons. The energy stored in each beam of 362 MJ. In a previous paper the mechanisms causing equipment damage in case of a failure of the machine protection system was discussed, assuming that the entire beam is deflected into a copper target. Another failure scenario is the deflection of beam into carbon material. Carbon collimators and beam absorbers are installed in many locations around the LHC to diffuse or absorb beam losses. Since their jaws are close to the beam, it is very likely that they are hit first when the beam is accidentally deflected. Here we present the results of two-dimensional hydrodynamic simulations of the heating of a solid carbon cylinder irradiated by the LHC beam with nominal parameters, carried out using the BIG-2 computer code* while the energy loss of the 7 TeV protons in carbon is calculated using the well known FLUKA code**. Our calculations suggest that the LHC beam may penetrate up to 10 m in solid carbon, resulting in a substantial damage of collimators and beam absorbers.

*V. E. Fortov et al. Nucl. Sci. Eng. 123 (1996) 169. **A. Fasso et al. The physics models of FLUKA: status and recent development, CHEP 2003, La Jolla, California, 2003.