The estimation of neutron energy spectra of nuclear materials by passive measurements for nuclear nonproliferation applications

The development of technologies to accurately characterize nuclear materials is becoming an area of significant importance in the United States and internationally. The development of new measurement systems with improved characterization capabilities is a top priority. Specifically, the study of neutron detection via passive measurement yields many opportunities. In this research, passive measurements were performed on mixed-oxide samples (MOX) and several isotopic neutron sources at the Joint Research Centre in Ispra, Italy in June of 2010. These measurements are used to test the capabilities of a neutron detection system and analysis algorithms developed at the University of Michigan. The measurements are also utilized to evaluate the use of liquid scintillation detectors for the determination of neutron energy distributions emitted from MOX samples and from various isotopic neutron sources. This measurement campaign provided the opportunity to identify and evaluate new candidates for the replacement of current detector technologies.