Author: Russenschuck, S.
Paper Title Page
TUPFI044 LHC Optics with Crab-waist Collisions and Local Chromatic Correction 1448
  • J.L. Abelleira, S. Russenschuck, F. Zimmermann
    CERN, Geneva, Switzerland
  • C. Milardi, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
We report the status of the optics design for a local chromatic correction with extremely-flat beams at the LHC. Together with a Large Piwinski angle, this optics opens up the possibility of crab-waist collisions at the LHC, for which a new layout of the LHC insertion region (IR) is needed. We present a complete optics and discuss the parameters of the final "double-half" quadrupole.
WEPEA059 Study of the Impact of Fringe Fields of the Large Aperture Triplets on the Linear Optics of the HL-LHC 2642
  • B.J. Holzer, R. De Maria, S. Russenschuck
    CERN, Geneva, Switzerland
  • R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
    UMAN, Manchester, United Kingdom
  • L.N.S. Thompson
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
High-luminosity hadron colliders such as the High Luminosity LHC (HL-LHC) project place demanding requirements on existing and new magnet technology. The very low β* achieved by the Achromatic Telescopic Squeeze (ATS) optics scheme* for the HL-LHC in particular, requires large apertures in the high gradient Nb3Sn final focusing inner triplet triplet. Such magnets have extended fringe fields which perturb the linear and non-linear optics. This paper presents results of studies into the liner optics of the LHC using a range of fringe field models, including measurements of fringe fields from prototype magnets, and presents calculations of the beta-beating in the machine. Furthermore a similar study is presented on the nominal LHC optics, which uses final focus quadrupoles of higher gradient but significantly smaller aperture.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for
LHC Upgrade’’, in proceedings of IPAC11, p. 2088.