Validation of energy moments from the one-dimensional energy dependent neutron diffusion equation, MCNP5 and Attila-7.1.0 with the GODIVA experiment

Normalized neutron energy moments (moments) from the one-dimensional energy dependent neutron diffusion equation (EDNDE), Monte Carlo N Particle 5 version 1.40 (MCNP5) and Attila-7.1.0-beta version (Attila) are validated with the GODIVA experiment (GODIVA). Energy moments 0–5 for all three methods are compared to GODIVA moments. GODIVA moments are measured with two methods. The 1st method is a time of flight (T-O-F) measurement of the average energy (moment 1) of the leaking neutrons from the surface of GODIVA and the 2nd method is from back calculating moments from foil activation analysis of various metal foils at the center of GODIVA. The error range of the EDNDE normalized moments compared to GODIVA is from 0% to 24%. The MCNP5 error range compared to GODIVA is 0–12% and the Attila error range is 0–79%. The method of moments is shown to be a fast reliable method, compared to either Monte Carlo methods (MCNP5) or 30 multi-energy group methods (Attila) with regard to the GODIVA experiment.

► Validated normalized energy moments 0–5 with GODIVA experimental values.
► Validated energy moments 0–5 from MCNP5 and Attila with GODIVA.
► Neutron energy moments from each method match expected physical intuition.
► Results of neutron diffusion energy moments are within 0–24% of GODIVA moments.