Explosives detection using dual energy X-ray imaging and photoneutron analysis

To find the explosives concealed in cargos, X-ray penetration information and neutron induced ¿ information are both helpful. The combination of them would improve the capability of explosives detection in complex situation like metal shielded or other organic materials disturbed. In this paper, we present the research of combining dual energy X-ray imaging and photoneutron induced ¿-ray analysis. The former technique provides the materials identification capability based on effective atomic number that indicates organic, light metal, inorganic and heavy metal areas. The area containing organic material will be suspected further that will undergo neutron analysis. High energy X-ray induced photoneutron analysis provides the 2-dimensional elemental distribution of hydrogen, nitrogen and iron. Area wealthy of nitrogen and hydrogen element may be suspected as to be explosive. Several different shielding situations are researched in the experiments to evaluate the explosive detection capability, including explosive standing alone, shielded by 2cm iron plate, surrounded by sugar and so on. 9MeV and 6MeV X-ray pulses are produced interlaced with 5¿s pulsed width and 3000rad/min@1m to form dual energy X-ray image. Neutrons are produced by X-ray with 20kg heavy water converter. The experiments results show that areas of organic materials could be first notified by dual energy imaging effectively, then the 2-dimensional elements information of nitrogen and hydrogen are used to confirm the existence of explosive.