Source options for nuclear weapons identification system

This report briefly presents the advantages and disadvantages of two timed sources of neutrons that can be used with the source-driven noise analysis method: (1) {sup 252}Cf in an ionization chamber and (2) an associated-particle sealed tube neutron generator (APSTNG). These sources can be used with frequency and time analysis methods for nuclear weapons identification, quality assurance in production, special nuclear materials assay, criticality safety, and provision of measured data for verification of neutron and gamma ray transport calculational methods. The advantages of {sup 252}Cf for a nuclear materials identification system are that it is simple, reliable, and small and that all source events are detected. The disadvantages are that it cannot be turned off, leads to small radiation doses in handling, and produces more than one neutron per fission event. The advantages of APSTNG are that it is directional, can be turned off, and has one particle per deuterium-tritium reaction. The disadvantages are that it is large and complicated compared to {sup 252}Cf