Solution of the fixed source neutron diffusion equation by using the pseudo-harmonics method

The two-group neutron diffusion equation, in two-dimensional Cartesian geometry, with fixed source was solved by using a pseudo-harmonics expansion method in connection with the flux expansion method of nodal discretization, based on average values. The same fixed source problem was solved by finite difference discretization and the results obtained were compared. The pseudo-harmonics expansion method employed is part of the alternative version of the pseudo-harmonics perturbation method and the fixed source problem tested was the “auxiliary function” problem. Results obtained for the test cases show that the method developed for solving fixed source problems is very accurate when compared to the finite difference method.