Neutron Imaging Overview
Brookhaven National Laboratory
There are several different types of new technology that are being developed for creating images using neutrons. Security applications include characterization of objects inside containers emitting neutrons, counting of multiple sources, as well as stand-off detection and localization.
The motivation for developing the technologies may be for cooperative treaty verification, nuclear safeguards or for countering nuclear smuggling and terrorism. The technologies can be passive or active, and may be sensitive to fast neutrons or thermal neutrons. Some instruments rely on coded apertures to produce an image, while others estimate elastic scattering angles, or generate a transmission radiographic pattern that can be enhanced by also detecting an associated particle produced simultaneously with each neutron. Each of these technologies provides limited information about an unknown object, constrained by source strength, shielding, imager angular resolution and stand-off distance.
Traditional neutron radiography performed with high-flux beams of cold neutrons will not be discussed in the present paper.