Moments Method Calculation of the Energy-Dependent Neutron Flux Due to a Point-lsotropic Fission Source in an Infinite Medium of Sodium

The energy-dependent neutron flux has been calculated for a point-isotropic fission source as a function of distance from the source in an infinite medium of sodium. The results were obtained by the moments method. Energy spectra are presented graphically for five distances from the source between 0 and 8 m and for energies between 1 eV and 15 MeV. Error estimates due to causes other than cross-section uncertainties or interpolations are made. The calculations are compared with a previously reported Monte Carlo calculation and with experimental measurements. Satisfactory agreement is observed.