"SECURITY: Research enlists radiation to reveal hidden bombs"

M2 Technologies Inc. (Manhattan, Kan.) is teaming with Kansas State University professor William Dunn to develop a technology for detecting explosives from several meters away. The developers are tapping established gamma and neutron radiation sources and phenomena to build a system that they believe will detect explosives from a greater distance than the "sniffer" technologies proposed by others. "We are trying to address the problem of looking inside packages-vehicles or backpacks or whatever-to see when the contents have the characteristics of an explosive," said Dunn. "We are not using sniffing technology but instead are looking at the target with radiation that penetrates its surface and interrogates the contents, after which we look at the characteristics of the radiation that returns." Gamma rays "backscatter" from molecules to create a distinctive radiation pattern whose signature can be detected and analyzed to determine a container's contents. By using short pulses of gamma rays, any suspicious substances can be detected.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=170100747