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Sapinski, M.

Paper Title Page
TUPTPF066 Operational Limits of Wire Scanners on LHC Beam 274
 
  • M. Sapinski, T. Kroyer
    CERN, Geneva
 
 

Wire scanners are instruments to measure the transverse beam profile. The measurement is performed by moving a thin wire across the path of the particle beam while monitoring the secondary particles. One of the limiting factor in application of wire scanners for high-intensity beams is the wire resistance to high temperature. In this work a heat flow equation for a carbon wire passing through a particle beam is solved. The equation contains modeling of wire heating induced by electromagnetic field of the beam and by electronic energy loss of the protons passing through the wire. The cooling processes considered are conduction, radiation, thermionic emission and sublimation enthalpy. Due to the equation nonlinearity a numerical approach based on discretization of the wire movement is used. An estimation of the wire sublimation rate is made. The model is tested on SPS and LEP data. An other limitation of a wire scanner application is a superconducting environment. The energy deposition in the magnet coils of downstream superconducting LHC magnets is estimated using Geant4 simulation package. In conclusions the limits of Wire Scanner operation on LHC beams are drawn.