Angular finite element techniques in neutron transport

Abstract The introductory part of this work analyzes the possibility of reducing ray effects deeply rooted with the angular discretization techniques adopted to solve the neutron transport equation, by the use of angular finite elements. Such reduction can be foreseen on pure physical grounds, considering the diffusive wave form assumed by the equations of the discrete model. A larger effort is then devoted to 2D problems, for which it is shown that, in general, it is possible to cast the finite element equations into a formal S N form. That is quite a fortunate circumstance, that will enable to exploit well assessed and tested numerical methodologies, devised for finite difference S N in quite more sophisticated finite elements applications. Some explicit cases are then taken into consideration, using simple angular element shape functions, for which a few numerical results of reference calculations are also presented.