Advanced transverse integration for the method of characteristics

A novel technique for a better computation of transmission probabilities has been developed for the method of characteristics in unstructured meshes (MOC). This technique relies on a transverse quadrature that properly accounts for discontinuities along trajectories, without penalizing the transverse step, and on the use of a Taylor expansion for the transverse integration of the transmission probability. The implementation of this new technique has proved rather successful, insofar as the method requires a much larger tracking step (up to Ave times) than the regular MOC to obtain a given accuracy for the reaction rates. (authors)