Neutron Car Wash
More than 90% of goods are transported via sea in cargo containers, but only a small fraction of these containers are physically inspected, making it possible for terrorists to hide explosive materials inside. Failure to detect even a small amount of such materials can endanger a country. In response to this problem, the ‘Neutron Car Wash’ was developed by the Lawrence Livermore National Laboratory in the U.S. A scanner-like device, it enables customs inspectors to probe the interior of trucks and cargo containers without having to physically open them. The device works by using a high-energy neutron probe to scan the containers, with the beta and gamma rays emitted used to produce grainy images on a computer monitor. If the operator sees objects that do not match the container’s listed items, the container can be shunted off for closer inspection.
The U.S. Bureau of Customs and Border Protection has installed this device in almost 100 ports and border points in the United States. It has proven effective and reliable, as well inexpensive to maintain. A major advantage is that it can detect explosives like plutonium and uranium which a normal X-ray scanner cannot. The device rarely causes false alarms, as the detection is carried out via chemical reactions that will not occur if such prohibited materials are absent.