The EURITRACK inspection concept: (1) X-ray radiography to detect and localise suspicious items inside the cargo container; (2) tagged neutron inspection after focusing the beam on the area of interest; (2.1) neutron flight-path spectrum to determine the depth of interest inside the cargo container; (2.2) gamma-ray spectra corresponding to different “slices” along the tagged neutron beam; (3) gamma spectra unfolding with a linear combination of elemental gamma spectra (C, O, N, Fe…); (4) C, N, and O relative proportions in a triangle representation (see text for details) to sort explosives and narcotics from benign materials.