The discrete cones method for two-dimensional neutron transport calculations

A novel method, the discrete cones method (DC_N), is proposed as an alternative to the discrete ordinates method (S_N) for solutions of the two-dimensional neutron transport equation. The new method utilizes a new concept, discrete cones, which are made by partitioning a unit spherical surface that the direction vector of particles covers. In this method particles in a cone are simultaneously traced instead of those in discrete directions so that an anomaly of the S_N method, the ray effects, can be eliminated. The DC_N method has been formulated for X-Y geometry and a program has been created by modifying the standard S_N program TWOTRAN-II. Our sample calculations demonstrate a strong mitigation of the ray effects without a computing cost penalty.