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Faus-Golfe, A.

Paper Title Page
TUPAN085 LHC Impedance Reduction by Nonlinear Collimation 1571
 
  • J. Resta-Lopez, A. Faus-Golfe
    IFIC, Valencia
  • F. Zimmermann
    CERN, Geneva
  
  A nonlinear collimation system can allow larger aperture for the mechanical jaws, and it thereby can help to reduce the collimator impedance, which presently limits the LHC beam intensity. Assuming the nominal LHC beam at 7 TeV, we show how a nonlinear betatronic collimation insertion would reduce considerably the LHC coherent tune shift for the most critical coupled-bunch mode as compared with the conventional baseline linear collimation system of Phase-I. In either case, the tune shifts of the most unstable modes are compared with the stability diagrams for Landau damping.  
THPMN056 Comparison of ILC Fast Beam-Beam Feedback Performance in the e-e- and e+e- Modes of Operation 2832
 
  • M. Alabau, A. Faus-Golfe
    IFIC, Valencia
  • P. Bambade
    LAL, Orsay
  • A. Latina, D. Schulte
    CERN, Geneva
  
  Several feedback loops are required in the Beam Delivery System (BDS) of the International Linear Collider (ILC) to preserve the luminosity in the presence of dynamic imperfections. Realistic simulations have been carried out to study the performance of the beam-beam deflection based fast feedback system, for both e+e- and e-e- modes of operation. The beam-beam effects in the e-e- collisions make both the luminosity and the deflections more sensitive to offsets at the IP than in the case of the e+e- collisions. This reduces the performance of the feedback system in comparison to the standard e+e- collisions, and may require a different beam parameter optimization.  
FRPMN078 Improved Algorithms to Determine Non-Linear Optics Model of the SPS from Non-Linear Chromaticity 4231
 
  • R. Tomas, G. Arduini, G. Rumolo, F. Zimmermann
    CERN, Geneva
  • R. Calaga
    BNL, Upton, Long Island, New York
  • A. Faus-Golfe
    IFIC, Valencia
  
  Funding: This work is partially supported by the U. S. DOE

In recent years several measurements of the SPS non-linear chromaticity have been performed in order to determine the non-linear optics model of the SPS machine at injection energy for different cycles. In 2006 additional measurements have been performed at injection and during the ramp for the cycle used to accelerate the LHC beam. New and more robust matching algorithms have been developed in 2006 to fit the model to the measurements up to arbitrary chromatic order. In this paper we describe the algorithms used in the analysis of the data and we summarize and compare the results from all experiments.