Rapid Characterization of Fresh Nuclear Fallout using Full-Spectrum Inverse Transport Methods
Abstract
Post-detonation forensic analysis of debris from a nuclear explosion currently relies on radiochemical separation. Although radiochemical separation is capable of developing a very detailed, highly accurate characterization of nuclear fallout, it is extremely time-consuming. Furthermore, characterization of short-lived fission products is made challenging or even impossible by the need to transport fallout samples from the detonation site to a radiochemistry laboratory. Analytical techniques that enable early characterization of nuclear fallout using field-deployable instruments can supplement traditional radiochemical analyses. In particular, gamma spectroscopic analysis of fallout has the potential to provide the needed early characterization in the field. Recent graduate research at the Air Force Institute of Technology (AFIT) has demonstrated limited capability to characterize pre-detonation nuclear explosive properties including fissile material and neutron spectrum. However, the recent AFIT research was based entirely on the analysis of gamma spectrum photopeaks (primarily using ratios of closely-spaced photopeaks), which were trended versus fissile material, neutron spectrum, and time after detonation. North Carolina State University (NCSU) proposes to conduct basic research to apply full-spectrum inverse analysis methods to the early characterization of nuclear fallout. Full-spectrum analysis methods employ detailed models of the gamma source term coupled to a detector response function to model all spectral features, including photopeaks and associated Compton continua. Inverse transport methods can be applied to estimate parameters of the gamma source term, including fissile material and neutron spectrum. NCSU will develop full-spectrum inverse transport analysis methods applied to the characterization of nuclear fallout and evaluate their utility for estimating pre-detonation nuclear explosive properties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 26, 2016
- Source ID
- HDTRA11610010
Entities
People
- Johnkelly Mattingly
Organizations
- Defense Threat Reduction Agency
- North Carolina State University