The DPN 'surface flux' integral transport method with general Psub(N) polynomial approximation

A new type of 'surface currents' method to solve the one and two dimensional neutron transport problems using Legendre polynomial approximation of the flux in both angle and space, and the orthogonal Legendre polynomial or spherical function approximation of the incoming and outgoing surface flux is currently being developed. One dimensional slab, spherical and cylindrical geometries and two dimensional X-Y and hexagonal geometries are handled. The method is presented on an example for plane, spherical and cylindrical geometry. The capability of the orthogonal DPN approximation of the surface angular flux is also checked. This type of approximation is systematically used with modifications (QPN, HPN) in other geometries. (Auth.)