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Papaphilippou, Y.

Paper Title Page
MOPC009 Experiments on LHC Long-Range Beam-Beam Compensation and Crossing Schemes at the CERN SPS in 2004 686
 
  • F. Zimmermann, J.-P. Koutchouk, F. Roncarolo, J. Wenninger
    CERN, Geneva
  • Y. Papaphilippou
    ESRF, Grenoble
  • T. Sen, V.D. Shiltsev
    Fermilab, Batavia, Illinois
 
  Experiments with two prototype long-range beam-beam compensators (current-carrying wires) during the 2004 CERN SPS run explored the efficiency of a proposed long-range beam-beam compensation for the LHC. In addition, the SPS compensators were also used to 'simulate' the effect of different planes of crossing at two LHC interaction points. We present the experimental results and compare them with computer simulations.  
WOAC010 Measurement of Linear Lattice Functions in the ESRF Storage Ring Using Turn-by-Turn Data 698
 
  • Y. Papaphilippou, L. Farvacque, J.-L. Revol, V. Serriere
    ESRF, Grenoble
  • S.-L. Bailey
    The College of William and Mary, Williamsburg
 
  A model-independent method to measure linear optics functions has been tested in turn-by-turn data from the ESRF storage ring. This method does not necessitate neither the knowledge of the model nor magnetic element manipulation. It uses only the positions measured in consecutive BPMs of betatron oscillations issued by small transverse kicks. The phase advances and tunes necessary to construct the transfer matrices are issued by refined Fourier analysis. The method's precision is compared with classical methods such as response matrix analysis and beam matrix construction.  
RPAE027 Linear Optics Measurements in the ESRF Booster 1973
 
  • Y. Papaphilippou, L. Farvacque, E. Plouviez
    ESRF, Grenoble
  • A. Mostacci, A. Patriarca
    Rome University La Sapienza, Roma
 
  A series of experiments has been conducted in the ESRF booster in order to measure its linear optics. A steerer response matrix was developed and used to optimise the orbit correction at injection by developing a refined model. This matrix was also used to measure the beta functions along the accelerating cycle and the steerer calibration. Dispersion was also measured with classical RF scans and compared to theory. Finally, chromaticity measurements were performed for different sextupole settings enabling their calibration and optimisation.  
RPAE028 Lattice Upgrade Options for the ESRF Storage Ring 2047
 
  • Y. Papaphilippou, P. Elleaume, L. Farvacque, A. Ropert
    ESRF, Grenoble
 
  Several scenarios of lattice upgrade for the ESRF storage ring are under study. In order to minimise the cost, their design is based on the length constraints of the existing tunnel with the ID beamlines kept in place. The goal is to shrink the emittance in order to increase the undulator brilliance. The two main options are a double bend achromat structure with non-uniform field dipoles and a triple bend achromat lattice. The two scenarios are detailed and compared with respect to their linear optics solutions, correction of chromatic effects and non-linear dynamics. An attempt to reveal the horizontal effective emittance dependence on important design parameters, such as optics functions maxima, chromaticity and dynamic aperture, is also undertaken. Technological challenges concerning magnet design with small physical aperture in a reduced space are also addressed.  
RPAE029 Analytical Considerations for Reducing the Effective Emittance with Variable Dipole Field Strengths 2086
 
  • Y. Papaphilippou, P. Elleaume
    ESRF, Grenoble
 
  The basic optics design scope in lepton rings is to match the sections in either side of the bending magnets in order to minimise the equilibrium emittance. A further important emittance reduction can be achieved by incorporating dipoles for which the deflecting field varies along the electron beam path in the magnet. The figure of merit for such lattices when used in a synchrotron light source is the minimization of the so-called effective emittance. The effective emittance is computed in the middle of the undulator straight section as the product of the rms size and divergence and therefore includes contributions from the betatron emittance and from the electron energy spread. In this paper, analytical formulas are obtained for the minimum betatron and effective emittance in arbitrary dipole fields and the associated optics function at the dipole entrance. Examples are given for specific dipole field functions and their properties with respect to the effective emittance minimisation. Finally, the effective emittance is parameterised with respect to standard cell optics properties, such as the phase advance, the maximum beta and dispersion functions and the focusing element strengths.