SIS 100 high current design challenges

1
SIS 100 high current design challenges

• Beam loss in SIS 100 needs to be carefully
  quantified within 1 level
• Non-standard beam and machine parameters
• Space charge tune shift -?Q0.2-0.3 during
  accumulation for 1 s (105 turns)
• The beam fills more than 1/2 of the elliptical
  beam pipe at injection
• Superconducting magnets with nonlinear field
  components
• Intrabeam and residual gas scattering for U28
  beam ions
• High beam intensity and low momentum spread
  tight impedance budget
• Electro-magnetic interaction with many
  non-standard ring components
• Finally bunch compression with extreme ?Q for a
  few turns.

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SIS100-4 High current beam dynamics studies
Partners

• Tasks
• Task 1 Lattice optimization studies
• Code benchmarking
• Beam loss and collimation studies
• Error compensation strategies
• Task 2 Collective instabilities and impedances
• Code benchmarking
• Impedance budget and feedback studies
• Impedance models
• Task 3 Full design verification studies
• Accumulation, rf cycle, bunch compression

• GSI, Darmstadt
• High current beam physics group
• Contact O. Boine-Frankenheim
• Berkeley Natl Lab., USA
• Accelerator modeling group
• Contact R. Ryne
• Brookhaven Natl Lab, USA
• Accelerator division
• Contact N. Malitsky
• TU Darmstadt
• Theorie elektromag. Felder
• Contact Prof. Th. Weiland
• Uni. Bologna, Italy
• Nonlinear dynamics group
• Contact Prof. G. Turchetti

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Task 1 Lattice optimizationEffect of space
charge, field errors and noise
Partners Bologna, GSI, Berkeley

• Long-term simulations of beam loss induced by
  field errors and space charge
• Comparison of multipole expansion (GSI) and
  detailed field tracking codes
• Benchmarking of frozen and self-consistent
  space charge modules
• Effect of intra-beam scattering (IBS) and other
  sources of noise on beam loss
• Comparison of different approaches to IBS in
  tracking codes,
• like Langevin forces or
  collision-maps.
• Tests with simple nonlinear maps

• Status
• Benchmarked tracking code with frozen space
  charge and multipole expansion (GSI).
• Experience with field maps (Berkeley)
• IBS modules from Bologna group and GSI-INTAS
  project.
• Schedule
• Module development, experiments and benchmarking
  finished after 12 month
• Final report on application to SIS 100 after 18
  month

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Task 2 Impedance budgetSpace charge and
impedance effects
Partners Brookhaven, GSI, TU Darmstadt

• 3D simulation studies of (long-term) impedance
  effects in SIS 100
• Comparison of impedance modules (time/frequency
  domain) for tracking codes
• For the space charge impedance fast Poisson
  solvers with elliptic boundaries
• Impedances studies (for all beam energies)
• Thin beam pipe (also with different coatings)
• Ferrite loaded kicker modules
• Combined collimation/pumping ports
• Status
• UAL Unified Accel. Library (Brookhaven),
  Sliced 3D tracking code (GSI)
• Analytic (thin wall) and numerical (kickers)
  impedance studies (TUD) started.
• Position for SIS 100 impedance modeling
  announced (TU Darmstadt)
• Candidate for the SIS 100 related work at
  Brookhaven.
• Schedule
• Impedance library for SIS 100 after 12 month
• Report on impedance effects and impedance budget
  in SIS 100 after 18 month

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Task 3 Full design verification
Partners Brookhaven, Berkeley, GSI

• Joint application of the simulation tools to SIS
  100 key issues
• Verification of error compensation and
  collimation schemes
• Full rf cycle simulation
• Optimized bunch compression scenario

Schedule Final report, optimized design after
24 month