Approximate Estimators for Fluence at a Point in Monte Carlo Center-of-Mass Neutron Transport

Some approximate estimators for obtaining the fluence at a point in Monte Carlo neutron transport calculations are presented and compared with the commonly used next event estimator. These estimators do not require direct evaluation of the scattering probability using Legendre expansions of the differential angular cross sections. The estimators are particularly useful for Monte Carlo programs that sample scattering directions in the center-of-mass coordinate system.