Vehicle and container control for the presence of a dirty bomb

The possibility of the detection of > presence inside sea containers has been evaluated. The method proposed for detection of simultaneous presence of explosive and radioactive material inside the vehicle or container makes use of two active sensors (x-ray and neutron sensor) and one passive (neutron and gamma ray sensor). In the proposed system a commercial imaging device based on the x-ray radiography performs a fast scan of the container, identifies a "suspect" region and provides its coordinates to the neutron based device for the final "confirmatory" inspection. In the neutron sensor 14 MeV neutron beam defined by the detection of the associated alpha particles is being used. The object's nature is determined from passive, and neutron induced, gamma energy spectra measurements. Time-of-flight and gamma energy spectra have been measured for different explosives and simulants as well as for the number of radioactive materials hidden inside the vehicle and/or container.