Abstracts Brochure - CERN

WEPCH — Poster Session 28-Jun-06 16:00 - 18:00
scattering for the lattices currently proposed for the ILC Damping Rings, as IBS is a concern, especially for the electron
ring. A description of the code and its user interface, as well as results for the Damping Rings, will be presented.
*K. Bane, in Proceedings of EPAC2002, p.1443. **A. Terebilo, Accelerator Toolbox for MATLAB, SLAC-PUB-8732 and
www-ssrl.slac.stanford.edu/at/. ***K. Kubo et al. PhysRevST AB.8.081001 (2005).
Simulations of Electron Effects in Superconducting Cavities
Modeling the complex boundaries of superconducting
radio frequency (SRF) accelerating
cavities on a Cartesian grid is a challenge
for many Finite Difference Time Do-
C. Nieter, J.R. Cary, P. Messmer, D.S. Smithe, P. Stoltz (Tech-X) G.R.
Werner (CIPS)
main (FDTD) electromagnetic PIC codes. The simulation of such cavities require conformal (curve fitting) boundaries.
Modeling the full cavity including couplers and ports is fundamentally a three dimensional problem requiring
capability to run in parallel on large numbers of processors. We have recently added conformal boundaries using
the method of Zagorodnov* to the plasma simulation code VORPAL. Using this higher order boundary algorithm
and the surface physics package TxPhysics, we have begun studies of self-consistent electron effects in SRF cavities.
We have modeled the beam excitation of cavity modes and the effects of electron multipacting. Results from these
studies will be presented using the new user friendly visualization tool that now ships with VORPAL.
*I. A. Zagorodnov et al. “A uniformly stable conformal FDTD-method in Cartesian grids,” International Journal of
Numerical Modeling 16, 127 (2003).
Computing TRANSPORT/TURTLE Transfer Matrices from MARYLIE/MAD Lie Maps
Modern optics codes often utilize a Lie algebraic
formulation of single particle dynam- G.H. Gillespie (G.H. Gillespie Associates, Inc.)
ics. Lie algebra codes such as MARYLIE and
MAD offer a number of advantages that makes them particularly suitable for certain applications, such as the study of
higher order optics and for particle tracking. Many of the older more traditional optics codes use a matrix formulation
of the equations of motion. Matrix codes such as TRANSPORT and TURTLE continue to find useful applications in
many areas where the power of the Lie algebra approach is not necessary. Arguably the majority of practical optics
applications can be addressed successfully with either Lie algebra or matrix codes, but it is often a tedious exercise
to compare results from the two types of codes in any detail. Differences in the choice of dynamic variables, between
Lie algebra and matrix codes, compounds the comparison difficulties already inherent in the different formulations
of the equations of motion. This paper summarizes key relationships and methods that permit that direct numerical
comparison of results from MARYLIE and MAD with those from TRANSPORT and TURTLE.
PBO LAB (tm) Tools for Comparing MARYLIE/MAD Lie Maps and TRANSPORT/TUR-
TLE Transfer Matrices
Particle optics codes frequently utilize either
a Lie algebraic formulation or a matrix for- G.H. Gillespie, W. Hill (G.H. Gillespie Associates, Inc.)
mulation of the equations of motion. Examples
of codes utilizing the Lie algebra approach include MARYLIE and MAD, whereas TRANSPORT and TURTLE use
the matrix formulation. Both types of codes have common application to many particle optics problems. However,
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