===affil2:
Tufts University
===firstname:
Stephanie
===firstname4:

===firstname3:
Scott
===lastname2:
B\"{o}rgers
===lastname:
Friedhoff
===firstname5:

===affil6:

===lastname3:
MacLachlan
===email:
Stephanie.Friedhoff@tufts.edu
===lastname6:

===affil5:

===otherauths:

===lastname4:

===affil4:

===lastname7:

===affil7:

===firstname7:

===postal:
Tufts University
Department of Mathematics
503 Boston Ave
Medford MA 02155
===firstname6:

===ABSTRACT:
Monte Carlo methods are typically used for simulations of the forward-peaked scattering behavior of electron beams in radiation therapy. Grid-based discretizations, however, can provide more efficient simulations if optimal solvers can be found for the resulting linear systems. The multigrid method for model two-dimensional transport problems as presented in [B\"{o}rgers and MacLachlan, An angular multigrid method for computing mono-energetic particle beams in Flatland, J. Comp. Phys., 229 (2010), pp. 2914-2931] shows good performance with some dependence on the choice of scattering kernel. In order to understand this behavior local Fourier analysis can be applied to the two-grid cycle. Using this approach, expressions for the error-propagation operators of the coarse-grid correction and relaxation projected onto the fine-grid harmonic spaces can be found. In this talk, we discuss progress to date in applying local Fourier analysis to model two-dimensional transport problems. 
===affil3:
Tufts University
===lastname5:

===affilother:

===title:
Local Fourier analysis for model transport problems
===firstname2:
Christoph