An adaptive algebraic multigrid for multigroup neutron diffusion reactor core calculations

摘要

An adaptive algebraic multigrid solver has been constructed for the multigroup neutron diffusion equation in reactor core calculations. Coefficients for the weak connection approximation are calculated adaptively using the current approximation of the main eigenfunction. It is especially efficient if the multigrid solver is used for the reactor criticity calculation, where main eigenfunction presents naturally. The robustness is achieved by means of pivot selection and row reordering under prolongation operator construction.