Characterizing nuclear materials hidden in lead containers by neutron-tomography-driven prompt gamma activation imaging (PGAI-NT)

Abstract

Laboratories worldwide develop Prompt Gamma Activation Analysis (PGAA) towards a position-sensitive technique. A full 3D element mapping with adequate resolution is possible, but limited to small objects due to constrains of experiment time and neutron flux. An alternative method is the combination of prompt gamma activation analysis and neutron imaging. Radiography, or even a full tomography on a complex sample, can be completed in an hour, and this often provides enough information to define regions of interest in the sample. The detailed element analysis by PGAA is then carried out only at these spots, saving a substantial beam time. This option is best used for samples consisting of a few homogeneous parts. The method is presented on a nuclear forensic application. The experiments are compared to the results from sophisticated Monte Carlo calculations.