1. Beam Simulation at Cornell
Main Beam Transport
Beam Halo
Spin Transport
Gerry Dugan, Lawrence Gibbons, Brian Heltsley, RP, Dave Rubin, David Sagan
Ritchie Patterson UCSC, June 2002

2. Main Beam Transport What Why
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

3. 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…

4. Main Beam Transport - Cornell role
Help refine simulation tools
Develop tuning algorithms
Explore utility of simulating Source to Damping Ring

5. Beam Halo What Why 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.

6. Beam Halo studies Investigate halo sources Halo transport Damping ring
Touschek scattered particles
RF structure dark current …
Halo transport
Like main beam transport, but harder: depends on field nonlinearities in magnets

7. 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

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