Improvements to the Diffusion Synthetic Acceleration method in neutron transport with highly anisotropic scattering

Some modifications of the Diffusion Synthetic Acceleration (DSA) technique are proposed to face its loss of effectiveness when dealing with highly anisotropic scattering. A model case convergence analysis of the proposed techniques is performed; an extensive set of comparisons with results obtained by means of already assessed DSA modification techniques is reported for various scattering cross-section configurations. The importance of non asymptotic convergence velocity as a theoretical means to characterize and optimize different acceleration methods is also discussed.