Polynomial Characteristics Method for Neutron Transport in 3D extruded geometries

International audience- A polynomial expansion in the axial direction has been implemented in the Method Of Characteristics framework, for the solution of the mono-group, steady state neutron transport equation for 3D extruded geometries. This work has been realized in the context of the APOLLO3$^R$ project and, in particular, in the Two & three Dimensional Transport (TDT) module. In this paper we weigh up benefits and disadvantages of this approach, when comparing to the classical Step Characteristics (SC) approximation, already available in APOLLO3$^R$