Impurity Diffusion as a Possible Metal Chronometer for Pre-Detonation Nuclear Forensics

• Main Authors: Edward Peskie, Howard Hall
• Format: Article
• Language: English
• Published: Institute for Nuclear Security 2015-07-01
• Series: International Journal of Nuclear Security
• Subjects: nuclear security; global security; nuclear material; nuclear diffusion; nuclear forensics; pre-detonation nuclear forensics; binary alloys; multi-component systems; impurity; alloying element concentration; chronometer; metal chronometer; impurity diffusion
• Online Access: http://dx.doi.org/10.7290/V7RF5RZ3

The ability to determine the time since forming of seized nuclear material would provide crucial data to be used in its investigation. The time dependent processes of diffusion relevant to this need are examined; to include grain boundary diffusion, and discontinuous precipitation, and an assessment is performed of the utility of examination of impurity and alloying element concentration profiles for use as a pre-detonation nuclear forensics tool for determining the age of a metal sample. Several examples illustrate the effects of time on both binary alloys and multi-component systems. Parallels are drawn from studies of diffusion in mineral samples under geologic time and proposes modifications to that approach in order to determine the time since a metal sample was cast or formed.