Author: Strzelczyk, M.
Paper Title Page
WEEPPB014 The Magnetic Model of the LHC during the 3.5 TeV Run 2194
  • E. Todesco, N. Aquilina, M. Giovannozzi, M. Lamont, F. Schmidt, R.J. Steinhagen, M. Strzelczyk, R. Tomás
    CERN, Geneva, Switzerland
  • N.J. Sammut
    University of Malta, Information and Communication Technology, Msida, Malta
  The magnetic model of the LHC is based on a fit of the magnetic measurements through equations that model the field components (geometric, saturation, persistent) at different currents. In this paper we will review the main results related to the magnetic model during the run of the LHC in 2010-2011: with a top energy of 3.5 TeV, all components of the model but the saturation are visible. We first give an estimate of the reproducibility of the main components and multipolar errors as they can be deduced from beam measurements, i.e. orbit, tune, chromaticity, beta beating and coupling. We then review the main results relative to the decay at injection plateau, dependence on powering history, and snapback at the beginning of the ramp for both tune and chromaticity. We discuss the precision obtained in tracking the magnets during the ramp, where the persistent current components gradually disappear. We conclude by presenting the behaviour of the quadrupoles model during the squeeze. A list of the major changes implemented during the operation together with what are considered as the main open issues is given.  
TUPPR068 The Achromatic Telescopic Squeezing Scheme: Basic Principles and First Demonstration at the LHC 1978
  • S.D. Fartoukh, R. De Maria, B. Goddard, W. Höfle, M. Lamont, G.J. Müller, L. Ponce, S. Redaelli, R.J. Steinhagen, M. Strzelczyk, R. Tomás, G. Vanbavinckhove, J. Wenninger
    CERN, Geneva, Switzerland
  • R. Miyamoto
    ESS, Lund, Sweden
  The Achromatic Telescopic Squeezing (ATS) scheme [1] is a novel squeezing mechanism enabling the production of very low β* in circular colliders. The basic principles of the ATS scheme will be reviewed together with its strong justification for the High-Luminosity LHC Project. In this context, a few dedicated beam experiments were meticulously prepared and took place at the LHC in 2011. The results obtained will be highlighted, demonstrating already the potential of the ATS scheme for any upgrade project relying on a strong reduction of β*.
[1] S. Fartoukh, "An Achromatic Telescopic Squeezing (ATS) Scheme For The LHC Upgrade," IPAC'11, WEPC037, p. 2088 (2001).