Application of the wavelet expansion method in spatial-angular discretization of the neutron transport equation

This paper describes the wavelet expansion method for discretizing the angular and spatial variables in the neutron transport equation. Three special features are introduced: (a) the variation scheme is applied using the Daubechies scaling function as the trialing and weighting functions, (b) the corresponding expansion sequence is designed for the sweeping of nodes, and (c) the boundary conditions and interface conditions are expressed using the wavelet expansion. The numerical results of several benchmarks demonstrate that the new method is feasible for the spatial-angular discretization of neutron transport equation. It is accurate and suitable for solving the problems with large flux gradient.