Neutron Screening for Airborne Cargo
Detection of Explosives, Drugs, Nuclear Materials…
There is currently a massive political and scientific focus on the need to develop new explosive and contraband detection technologies. Recent terrorist attacks have identified vulnerabilities and stimulated activities to improve security in the transport industries.
At present, the detection of concealed contraband in air cargo is based mainly on the use of X-ray imaging. Most contraband, such as explosives and illicit drugs, are organic and consequently have low X-ray absorption. In addition, although some X-ray scanners can produce a sharp image as well as a density-dependent shading of the interrogated object, explosives and illicit drugs and can be moulded or packed into any form. This makes their detection very difficult through simple shape recognition.
Since neutrons are unaffected by electromagnetic forces they can penetrate deeply into matter, interacting only with nuclei. When a neutron interacts, the nuclide reacts in a unique way that depends on the incident energy of the neutron and the species of the target nuclide. In particular, the principal elemental constituents of narcotic and explosive substances differ strongly from one-another in their interactions with neutrons and can therefore be characterized via these differences.
We are constructing a cut down prototype of a neutron screening device that will integrate radiographic information from the generator gamma flash and the transmitted neutrons with the activation signatures resulting from neutron absorption in the scanned material. This fusion of information will provide image information as well as the elemental composition of the scanned cargo.
|John McMillan||Val O'Shea|
|Department of Physics and Astronomy, The University of Sheffield||Department of Physics and Astronomy, University of Glasgow|
|Supported by EPSRC EP/G005141/1|