Optimizing cell importances using an extension of the DSA -theory, implementation, preliminary results

Starting from the theoretical results of the extension of Dubi's Direct Statistical Approach (DSA) surface parameter particle transport model to a cell importance model, a computer code based on the Monte Carlo Neutron Photon (MCNP) code has been written that directly estimates the second moment and time functions. Two versions have been developed: one that estimates the exact functions and the other that estimates the point-surface approximation functions. Preliminary results obtained using the two versions are presented. (author)