Year
2001
Abstract
This paper describes the electromagnetic (EM) coil concept, theory of operation, and test results of a laboratory prototype measurement system for obtaining unique electromagnetic signatures of weapon components stored inside sealed metal containers. Detailed weapon component information cannot be derived from this procedure’s two-parameter coil impedance measurement because the electromagnetic signature depends upon too many parameters, including electromagnetic properties, total mass, total mass distribution, and geometric orientation. The placement of each unique electrically conductive object, or combination of objects, inside the EM coil results in a unique signature. When metal storage containers are nearly identical, as in the case of most stainless steel containers, it is a straightforward procedure to identify Pu components in sealed containers, as well as verify the declaration of their absence. However, for containers such as the carbon-steel AL-R8, where each container has slightly different parameters, a dual coil location measurement technique is required to meet this objective. To date, EM signatures for both Pu and U components have been determined for several different weapon programs and they show clear discrimination between these two component types.