FCC-ee top-up injection

Europe/Zurich
Zoom Meeting ID
66156014911
Host
Yann Dutheil
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Present: Y. Dutheil, G. Gonen, M.A. Jebramcik, T. Mori, G. Nigrelli, K. Skoufaris, S. Yue
 
 
 
New colleagues:
  • Marc-André (ABP): Linear/non-linear optics, working on LCC w/ Pantaleo
  • Gal (ABT): Tracking studies on MIK injection scheme

Top-Up Injection Status gitlab link

  • Repository updates 
    • Loss locations (S7): Discrepancies between SAD and Xsuite, Takashi will update the loss output to show meters instead of element ID
    • Beam matching issues at injection likely linked to beam-beam element.
      • S8 simulations without beam-beam still show injection inefficiency.
    • Simulation comparison:
      • with beam-beam SAD: ~80% efficiency. Xsuite: ~66% efficiency.
      • Large discrepancy on beam-beam impact 
        • much larger than results showed at FCCweek 
      • Potential source:
        • mismatch in injected beam parameters.
        • injected beam in Xsuite uses the SAD distribution
        • Giulia and Kyriacos + several others working on a tool set that will ensure setup and reproducibility of results
        • Marc-Andre recommends to check the beam-beam force effect on the lattice w/o SR and using FFT on the tracking

Nonlinear Kickers and Injection Schemes

  • Review presented at low emittance workshop 2024 here by P. Alexandre (ESRF)
  • Present work in ABT aim at establishing specifications for a MIK
  • for FCC
    • Initial work by P. Hunchak, for instance here
    • no bump of circulating beam
  • Marc-André matching universal straight from GHC section to LCC. -> LCC will be available soon as drop-in replacement for the purpose of injection tracking
There are minutes attached to this event. Show them.
    • 14:00 14:20
      Collider repo progress 20m
      Speaker: Sen Yue (CERN)
    • 14:20 14:40
      Non-linear kicker plans 20m
      • Non-linear kickers have been installed (Max IV, SOLEIL, SIRIUS) or are being developed (ESRF-EBS, SOLEIL2) at several facilities
      • Review presented at low emittance workshop 2024 here by P. Alexandre (ESRF)
      • for FCC
        • Initial work by P. Hunchak, for instance here
        • no bump of circulating beam
        • possibly simpler, thicker injection septum
        • but needs compensation (second non-linear kicker to compensate the non-linearity for the circulating beam) -> strong optics constraint on phase advance and dispersion

      • Status
        • specifications are being discussed
        • New summer student starting work of injection with MIK
      • Prospects
        • Need to study the impact of compensation error -> beyond the lattice choice
        • GHC lattice does not provide the required optics quantities -> can we use a fake-cMIK at the injection point for now, perfect compensation
          • possibly new distribution of the injection losses will require updated 
        • LCC lattice : no work as yet, but needs to be started within the next few weeks