SUMMARY

The objective of this research is to assess characteristics, effects, and limitations of prompt passively measurable signatures on early-time attribution conclusions ultimately influencing nuclear deterrence strategy. The goals and objectives are accomplished using experimental and computational methods. Various computational sensitivity/uncertainty analysis methods are performed on passively measured signatures generated during a nuclear detonation. The sensitivity studies are conducted with and without limiting phenomena affecting detectability such as environmental factors and detector technology. The resultant sensitivity indices provide an acceleration basis for an initial conditions search algorithm to determine various characteristics using prompt emissions. Furthermore, sensitivity and search algorithms consider uncertainty associated with the nuclear data. Compounding nuclear data uncertainty with current detector technology capabilities ultimately delimits early-time attribution conclusions. These computationally derived results are then applied to experimental measurements in a laboratory setting using different detector technologies. The measurements are completed using a pulsed neutron source with various fissile/fissionable isotope targets. These experiments demonstrate current detector technology limitations in a laboratory setting when applied to pulsed – short lived – emissions.