Beam Simulation at Cornell

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Beam Simulation at Cornell

• Main Beam Transport
• Beam Halo
• Spin Transport

Gerry Dugan, Lawrence Gibbons, Brian Heltsley,
RP, Dave Rubin, David Sagan
Ritchie PattersonUCSC, June 2002
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Main Beam Transport

• What
• Simulate beam transport from Source to Damping
  Ring and Damping Ring to Dump
• Why
• Evaluate emittance dilution in the face of
  wakefields, ground motion and mechanical noise
• Develop feedback algorithms
• Write specs for beam instrumentation

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Main Beam Transport - Tools Status

• Sophisticated simulations of beam transport from
  the damping ring to dump exist
• LIAR/DIMAD (SLAC), MERLIN (DESY) PLACET (CERN)
• Bunch generally represented as macroparticles
• R-matrix transport includes wakefields, B fields
  up to qudrupole or sextupole, misalignments, BPM
  resolutions

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Main Beam Transport - Cornell role

• Help refine simulation tools
• Develop tuning algorithms
• Explore utility of simulating Source to Damping
  Ring

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Beam Halo

• What
• Identify sources of beam halo
• Simulate halo transport
• Why
• Halo drives collimation design
• Affects background in detector
• Complete understanding of sources of halo has
  been elusive. Eg, SLC simulations significantly
  underestimated halo.

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Beam Halo studies

• Investigate halo sources
• Damping ring
• Touschek scattered particles
• RF structure dark current
• Halo transport
• Like main beam transport, but harder depends on
  field nonlinearities in magnets

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Spin Transport

• LC physics wants longitudinally polarized e-
  beam
• Common wisdom says that polarization of e- at
  source will be preserved during transport to IP.
• This project
• Check the common wisdom by simulating spin
  transport
• Identify potential sources of depolarization

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Budget
Year 1 Year 2 Year 3
Grad students (2) 80k 80k 80k
Computing hardw. 10k 20k
TOTAL 80k 90k 100k