The Neutron Spectral Distribution from a Godiva Type Critical Assembly

Neutron spectrum measurements were made at the White Sands Missile Range (WSMR) Fast Burst Reactor (FBR), a Godiva type critical assembly. The spectrum measurements were performed by neutron activation techniques coupled with the computer code SAND II. Results from this investigation reveal a spectral index of 6.7 for the leakage spectrum and 7.8 for the Glory Hole spectrum or, the neutron leakage spectrum of this Godiva type critical assembly is harder by - 30% when comparing its spectral index to previous measurements. Furthermore, the neutron spectrum measured in the Glory Hole for the FBR reveals that this spectrum is softer than the leakage spectrum by a factor of 1.16 for the spectral indicies.