| abstract |
A contraband detection system (18) using a single, cone shaped neutron beam determines substances concealed in a sample object by developing total neutron cross section spectra for a plurality of elements, including carbon, nitrogen, oxygen, hydrogen and other potential contraband-indicating elements. A processor (26) performs a contraband determination classification based on the neutron total cross section spectra for the plurality of elements, including hydrogen and elements which do not have peaks in the energy range of interest. The contraband detection system (18) includes a neutron source (20) for producing a pulsed, cone shaped beam of fast white neutrons; a spatial neutron detection array (40); a conveyor system (28) for situating a sample object (29) between the source (20) and the detection array (40); a spectra analysis system (24) for determining the neutron total cross section spectra of elements located in the sample object; and the processor (26). The neutron source (20) produces a pulsed beam (36) of fast white neutrons having sufficient energy range whereby removal of neutrons from the beam caused by the presence of a plurality of contraband-indicating elements can be determined. Various techniques of making contraband classification determinations are also disclosed. |