Angular Multigrid Acceleration Method and Lyusternik-Wagner Extrapolation Acceleration Technique for Two-Dimensional Neutron Transport Equation

To improve the efficiency of neutron transport computation, the angular multigrid （ANMG） acceleration method and the Lyusternik-Wagner extrapolation acceleration technique are utilized to accelerate the source iteration process. They are successfully applied to the LESFES code, which is developed to solve the neutron transport equation by the least-squares finite-element method. The numerical results demonstrate that the ANMG acceleration method can save much computation time not only for isotropic scattering problems but also for the highly anisotropic scattering problems. Furthermore, when the Lyusternik-Wagner extrapolation acceleration technique is applied to the ANMG acceleration method, the acceleration effect can be significantly improved.