The U.S. Defense Advanced Research Projects Agency (DARPA) has issued a call for proposals for research grants to develop a portable system that combines neutron radiography with conventional x-ray for nonmedical applications.
Neutron radiography uses neutrons to image objects and is very good at visualizing lighter elements and liquids -- it can even identify the atomic makeup of a substance, in some cases. But neutron sources are quite large, up to tens of meters in length, and require powerful energy sources to generate the neutrons.
Under the Intense and Compact Neutron Sources (ICONS) program, DARPA is hoping to develop a portable system that could generate both neutrons and x-rays. By combining both types of technologies, such a system could enable much more detailed radiography in the field.
At left, a digital camera picture of an open lead cask with flowers inside. At right, a neutron image acquired through the lead walls of the cask, demonstrating the power of neutrons to pass through otherwise "impenetrable" materials with enough sensitivity to reveal details such as the leaf veins. Image courtesy of DARPA.DARPA specifically is looking for proposals that would shrink a neutron accelerator from 10 m or longer down to 1 m or less, about the size of currently available portable x-ray tubes. Such a portable system could have a number of national security applications, such as visualizing water penetration and corrosion in aircraft wings or ship welds, or detecting explosives and contraband by identifying the chemical and atomic makeup of objects.
The announcement of the grant program is available here.
