FCC-ee top-up injection

→ Europe/Zurich
FCC-ee top-up injection
Zoom Meeting ID
66156014911
Host
Yann Dutheil
Useful links
Join via phone
Zoom URL
Hide

D. Calzolari, Y. Dutheil, J. Keintzel, S. Kostoglou, G. Nigrelli, A. Potet, P. Raimondi, K. Skoufaris, S. Yue

 

 

  • Present status of the WG simulations
  • Collider design pillar request for information
    • Q1 : What is the injection efficiency modelled in the presence of beam-beam and collimation ?
      • No resources identified are listing efficiencies of 0%
      • This remain an ongoing topic of discussion with continuous progress on both performance and inclusion of more physics processes
      • Besides including all physics processes, the injection process must be tested under perturbed conditions (corrected lattice) to test and quantify the robustness of the injection process.
      • Latest simulations conducted and presented by G. Nigrelli  https://indico.cern.ch/event/1588696/contributions/6856980/
    • Q2 : Is the injected beam position and Twiss parameters including both linear and non-linear dependency with momentum offset ?
      • Discussed during the WG meetings of 10/2026 and 12/2026 as well as by G. Nigrelli at the tune-up meeting in October
      • But need to understand and fix specific parameters -> Important to find the parameters and communicate them
      • Important to find the optimum injected beam parameters -> We need to establish a methodology to find new parameters with a new lattice
  • Giulia will discuss with Sen on how to incorporate or associate her simulation to a repository, for instance the https://gitlab.cern.ch/abt-optics-and-code-repository/projects/collider-injection-fcc-e
  • Marc-Andre on LCC
    • Previous lattices not optimised for injection or non linear dynamics
    • It would be important to conduct optimisation from a corrected lattice with errors (request to tune-up WG ?)
    • Conducting MOGA at large dE
      • voltage presently using 150 MV which is slightly away from the baseline set to 90 MV (convergence needs to be done on ABP-RF side)
      • Optimisation conducted to dispersion-free straight section
      • Optimised lattice is able to maintain the DA w/ beam-beam and epsY
      • At the location of the septum the optimisation includes up to DDX2 which may be the source of limited DA -> agreement that included higher order is important
    • Present point selected for higher MA but could be optimised for slightly larger DA for hybrid injection
    • How do we proceed from here ?
      • 90MV or stay at 150 MV for now ?
      • Should we switch to negative dE ? -> This is needed because we need lower RF voltage from the booster
      • Kyriacos asks if optimise directly on lifetime instead MA
        • MA should be a good proxy to lifetime but one scan should be conducted to confirm this
    • Marc-Andre will publish and make available a new lattice version, note this is not a new lattice but optimised element strength on LCC106
  • Sen on MIK progress
    • No time during the discussion, only conclusion with promising zero-phase-advance concept
    • The beam stay clear definition remains in question, Giulia will circulate the definition with beta and dispersion contributions
    • The pi-phase advance concept requires contributions from Marc-Andre to establish the feasibility in PB
    • Detailed discussion deferred to the next meeting
There are minutes attached to this event. Show them.