National Geographic : 2018 Feb
3 Nuclear material detected Locating nuclear material As the 3-D model is being created, a detector D scans the cargo for neutrons, produced when x-rays interact with nuclear material. When the data are combined with the 3-D model, an operator can pinpoint the location of any nuclear contraband. Nuclear isotope Neutrons Photon When photons strike nuclear material, neutrons radiate outward. A B D C B D D To avoid harmful doses of radiation, the driver pulls into the scanner, parks, and exits before the truck is sent through the system. D JASON TREAT AND RYAN T. WILLIAMS, NGM STAFF ART: MARK GRASSA SOURCE: PASSPORT SYSTEMS, INC.