An integrated system for non-destructive detection of shielded nuclear material using multiple modes of passive detection

In this work, an experimental assessment is made of the performance of an integrated system for the detection of shielded nuclear material that features muon tomography and polyvinyl toluene bi-panel detector systems. Experimental setups consisting of a barrel of sand containing a lead flask and/or depleted uranium were defined, and were measured in turn by each detection system. For each system, detection parameters for the presence of depleted uranium were put forward that can be used to integrate the two detection systems in a quantitative manner. In the integrated system, the detectability of differences between setups using a given detection parameter is quantitatively assessed through the use of relative operating characteristic (ROC) curves. Furthermore, in an effort to enhance detection sensitivity, pairs of parameters were combined, through sorting on either maximum or average values, to produce “data fusion” ROC curves. The efficacy of this approach and the complementarity of the detection techniques employed are discussed.