Author: Lefevre, T.     [Lefèvre, T.]
Paper Title Page
MOEPPB010 Measurement of Satellite Bunches at the LHC 97
  • A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo
    CERN, Geneva, Switzerland
  • A.S. Fisher
    SLAC, Menlo Park, California, USA
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  Funding: Adam Jeff is a DITANET fellow, supported by the EU's Marie Curie actions contract PITN-GA-2008-215080.
The RF gymnastics involved in the delivery of proton and lead ion bunches to the LHC can result in satellite bunches of varying intensity occupying the nominally empty RF buckets. Quantification of these satellites is crucial for bunch-by-bunch luminosity normalization as well as for machine protection. We present an overview of the longitudinal density monitor (LDM) which is the principal instrument for the measurement of satellite bunches in the LHC. The LDM uses single photon counting of synchrotron light. The very high energies reached in the LHC, combined with a dedicated undulator for diagnostics, allow synchrotron light measurements to be made with both protons and heavy ions. The arrival times of photons are collected over a few million turns, with the resulting histogram corrected for the effects of the detector’s deadtime and afterpulsing in order to reconstruct the longitudinal profile of the entire LHC ring. The LDM has achieved a dynamic range in excess of 105 and a time resolution of 90 ps. Example results are presented and the measurements are benchmarked against satellite distributions based on collision data from the LHC experiments.
MOPPR046 CLIC Luminosity Monitoring 885
  • A. Apyan, L.C. Deacon, E. Gschwendtner, T. Lefèvre
    CERN, Geneva, Switzerland
  • R. Appleby, S.C. Tygier
    UMAN, Manchester, United Kingdom
  The CLIC post-collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14MW to the main beam dump. Luminosity monitoring for CLIC is based on high energy muons produced by bremsstrahlung photons in the main dump. Threshold Cherenkov counters are proposed for the detection of these muons. The expected rates and layout for these detectors is presented. Another method for luminosity monitoring is to directly detecting the bremsstrahlung photons in the post-collision line; Full Monte Carlo simulation has been performed to address its feasibility.  
MOPPR057 Development of a Cavity Beam Position Monitor for CLIC 915
  • F.J. Cullinan, S.T. Boogert, N.Y. Joshi, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  • E. Calvo, N. Chritin, F. Guillot-Vignot, T. Lefèvre, L. Søby
    CERN, Geneva, Switzerland
  • A. Lunin, M. Wendt, V.P. Yakovlev
    Fermilab, Batavia, USA
  • S.R. Smith
    SLAC, Menlo Park, California, USA
  The Compact Linear Collider (CLIC) project presents many challenges to its subsystems and the beam diagnostics in particular must perform beyond current limitations. The requirements for the CLIC main beam position monitors foresee a spacial resolution of 50 nm while delivering a 10 ns temporal resolution within the bunch train. We discuss the design of the microwave cavity pick-up and associated electronics, bench top tests with the first prototype cavity, as well as some of the machine-specific integration and operational issues.  
TUPPC086 Conceptual Design of the CLIC damping rings 1368
  • Y. Papaphilippou, F. Antoniou, M.J. Barnes, S. Calatroni, P. Chiggiato, R. Corsini, A. Grudiev, J. Holma, T. Lefèvre, M. Martini, M. Modena, N. Mounet, A. Perin, Y. Renier, G. Rumolo, S. Russenschuck, H. Schmickler, D. Schoerling, D. Schulte, M. Taborelli, G. Vandoni, F. Zimmermann
    CERN, Geneva, Switzerland
  • C. Belver-Aguilar, A. Faus-Golfe
    IFIC, Valencia, Spain
  • A. Bernhard
    KIT, Karlsruhe, Germany
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • A.V. Bragin, E.B. Levichev, S.V. Sinyatkin, P. Vobly, K. Zolotarev
    BINP SB RAS, Novosibirsk, Russia
  • M. Korostelev
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • E. Koukovini
    EPFL, Lausanne, Switzerland
  • M.A. Palmer
    CLASSE, Ithaca, New York, USA
  • M.T.F. Pivi, S.R. Smith
    SLAC, Menlo Park, California, USA
  • R.P. Rassool, K.P. Wootton
    The University of Melbourne, Melbourne, Australia
  • L. Rinolfi
    JUAS, Archamps, France
  • A. Vivoli
    Fermilab, Batavia, USA
  The CLIC damping rings are designed to produce unprecedentedly low-emittances of 500 nm and 5 nm normalized at 2.86 GeV, in all beam dimensions with high bunch charge, necessary for the performance of the collider. The large beam brightness triggers a number of beam dynamics and technical challenges. Ring parameters such as energy, circumference, lattice, momentum compaction, bending and super-conducting wiggler fields are carefully chosen in order to provide the target emittances under the influence of intrabeam scattering but also reduce the impact of collective effects such as space-charge and coherent synchrotron radiation. Mitigation techniques for two stream instabilities have been identified and tested. The low vertical emittance is achieved by modern orbit and coupling correction techniques. Design considerations and plans for technical system, such as damping wigglers, transfer systems, vacuum, RF cavities, instrumentation and feedback are finally reviewed.