Consistent P1 synthetic acceleration method for outer iterations

A method is developed for P 1 synthetic acceleration of outer iterations. The method is consistent with the weighted diamond differencing discrete ordinates multigroup equation, and suitable for a negative flux fixup algorithm being used in transport calculations. The scattering anisotropy is considered in the most general form by means of the scattering matrix. Being applied to the slab geometry, heterogeneous, anisotropic scattering neutron thermalization problems, the method gives a gain by a factor of 3 to 5 in running time relative to an ordinary source iteration calculation. It is also shown, that a convergence rate of the method depends slightly on the spatial mesh.