Advanced quadratures for three-dimensional discrete ordinate transport simulations: A comparative study

Three-dimensional radiation transport simulations play a key role in a number of problems found in nuclear science and engineering. When considering deterministic methods for solving the three-dimensional radiation transport equation, the Sn method of Carlson and Lee is one of the most commonly found techniques. The Sn method relies on a given set of “discrete ordinates” or discrete directions in which radiation streams. This set of discrete ordinates also must form a quadrature (numerical integration) so that the angular flux moments can be estimated and the scattering source calculated. In this paper we review a number of recently developed angular quadrature sets and compare their performance on a number of reactor physics problems.