Neutron Spectrum Measurements at the White Sands Missile Range Fast Burst Reactor (FBR)

Abstract

Abstract : The White Sands Missile Range Fast Burst Reactor (FBR) is an unmoderated, unreflected bare critical assembly of the Godiva II type. The FBR is extensively used for producing a nuclear environment which stimulates the neutron portion of a nuclear weapon. Military systems are exposed to this environment for testing and analysis of their response to a nuclear weapon. The primary system degradation at the FBR is produced by neutron interactions within the system. Most of the military systems tested use solid state electronic devices. Neutron displacement and other neutron effects in the silicon devices cause the electronic degradation. The amount of damage produced by a neutron is a function of the neutron energy. The neutrons produced by the FBR have a continuous (fission) spectrum of energies. A complete characterization of this spectrum is essential in the evaluation of the nuclear effects on the system under evaluation.