A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Boccardi, A.

Paper Title Page
TUPC098 Results of the LHC Prototype Chromaticity Measurement System Studies in the CERN-SPS 1290
 
  • R. J. Steinhagen, A. Boccardi, T. Bohl, M. Gasior, O. R. Jones, J. Wenninger
    CERN, Geneva
  • K. K. Kasinski
    AGH, Cracow
 
  Tune and chromaticity control is an integral part of safe and reliable LHC operation. Tight tolerances on the maximum transverse beam excursions allow oscillation amplitudes of less than 30 um. This leaves only a small margin for transverse beam and momentum excitations required for measuring tune and chromaticity. This contribution discusses the baseline LHC continuous chromaticity measurement with results from tests at the CERN-SPS. The system is based on continuous tracking of the tune using a phase-locked-loop (PLL) while modulating the beam momentum. The high PLL tune resolution achieved ( ~1·10-6 ) made it possible to detect chromaticity changes well below the nominally required 1 unit for relative momentum modulations of only 2·10-5. The sensitive tune measurement front-end employed allowed the PLL excitation and radial amplitudes to be kept below a few tens of micrometers. These results show that this type of measurement can be considered as practically non-perturbative permitting its use even during nominal LHC operation.