The LHC 450 GeV to 7 TeV Synchrotron Radiation Profile Monitor using a Superconducting Undulator

In LHC it will be important to measure with precision and in a non-destructive way the proton beam profiles from 450 GeV to 7 TeV. The chosen Synchrotron Radiation Monitor will make use of a two-period 5 T superconducting Undulator coupled to the D3 bending magnet in IR4. From the various variants studied, this combination is the only one which can cover the whole LHC energy range. By locating both magnets in the same cryostat, it will be possible to minimise the light source length for best precision. The undulator and telescope parameters and basic design are described. The evolution of the synchrotron radiation patterns as well as the performance with respect to sensitivity, depth of field and diffraction along the energy ramp are given.