|LHC Proton Beams Diagnostics using Synchrotron Radiation (CERN-2004-007)|
|L. Ponce, R. Jung, F. Méot|
To carry out the transverse diagnostic of the LHC proton beams, it is planned to use a synchrotron light monitor. In order to optimize the performance over the whole LHC energy range (from 450 GeV up to 7 TeV), a comparative study of various types of source was undertaken. First of all based on analytical models making it possible to determine the angular spectral energy density emitted by these sources, then using simplifying models like the low frequency model or the interference between sources derivations, the study was completed by numerical simulations to evaluate the sources performances in more real use conditions. The results obtained made it possible to propose the installation of a two 28~cm long periods superconducting undulator, combined with a separation dipole to make it possible to measure profiles over all the energy ramp. Lastly, the monitor performance evaluation is supplemented by a detailed analysis of the optical system. First of all, the components of the telescope are described in order to evaluate the thresholds of detection. Then, the effects of diffraction and depth of field which constitute the limits of the system resolution were studied numerically. These results made it possible to come to the construction of a RS monitor making it possible to satisfy the LHC beams diagnostic requirements.