Diffusion-accelerated solution of the two-dimensional S[sub n] equations with bilinear-discontinuous differencing

A new diffusion synthetic acceleration scheme is developed for solving the two-dimensional S[sub n] equations in x - y geometry with bilinear-discontinuous finite element spatial discretization. This method differs from previous methods in that it is unconditionally efficient for problems with isotropic or weakly anisotropic scattering. Computational results are given that demonstrate this property.