Portland, Ore. - 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.
Conventional explosives used in bombs have similar ratios of nitrogen to oxygen to hydrogen to carbon-a detectable chemical signature. By supplementing gamma radiation with short bursts from other types of beams, such as neutrons, the technology under development can analyze a sample without "overdosing" it with the harmful gamma rays, the researchers said.
Gamma rays' high energy enables them to penetrate almost any container. Unlike sniffer technologies, which analyze samples of air from the vicinity of an object, gamma radiation does not depend on the trace amounts of the explosive on the outside of its container. The advantage, according to Dunn, is that gamma rays can reliably detect bombs from a greater distance.
"We need this kind of technology in toll booths, at turnstiles and in other public places," said Janet Morris, president and chief executive officer of M2 Technologies. "Maybe we can't stop [terrorists from] blowing up bombs, but we can keep them from doing it in crowded public places, and that will discourage this kind of tactic."
What the backscatter reveals
Dunn was enlisted by M2 Technologies to collaborate on the development because he is director of Kansas State University's Radiation Measurement Applications Laboratory, which has the facilities to conduct experiments using traditional radiation-backscattering techniques to measure the physical properties of matter. The laboratory specializes in the nondestructive evaluation of materials. The technique pelts the material with quick pulses of X-rays, gamma rays and neutrons and then measures the properties of the returning radiation.
M2 Technologies specializes in providing nonlethal technologies to military and law enforcement agencies as well as to the U.S. national security establishment. Since 1996, it has been working with the Department of Defense's Joint Non-Lethal Weapons Program (JNLWP) to develop the requirements and manage the acquisition of nonlethal capabilities ranging from stun guns to large-scale crowd control via microwaves.
For the remote-detection capability, M2's contract with the U.S. Marine Corps calls for a technology similar to computed tomography but with far lower radiation levels. With the system under development, suspect packages would not have to be put inside scanners like the ones used at airports to discern the contents.
"We are trying to protect troops, people and property," said Dunn. "We think that can be done from a distance of meters, not inches-which a sniffer can't do."
While gamma rays are dangerous, "we are taking the approach that we can do this job with a minimum amount of radiation, if we use as many measures as possible that all indicate the same thing," said Dunn. "We use gamma ray backscatter first; then, if we need to supplement that, we would use neutron radiation. When incident on the target, neutron radiation goes into the contents and stimulates certain characteristics of radiation that we can detect-things like a hydrogen-to-nitrogen ratio that is characteristic of an explosive."
The technology requires electronics for interrogating objects with radiation, processing the data and sending it to a remote location for review by appropriate personnel to eliminate false readings. Using automated subsystems, the system will rapidly perform a very high-precision analysis of returned data as well as include safeguards that will protect those nearby from radiation.
"We are trying to come up with ways of separating people from the things they bring along so that the object can be interrogated without exposing the people," said Dunn.
The team believes its success depends only on intensifying its development effort, since the technologies used are already well-established. "We are not dreaming up a new kind of sensor and then trying to build it," Dunn said.
Thus far the team has built and demonstrated a prototype, with laboratory-style equipment, to establish a baseline for remote explosives detection. "We have already established proof of principle, by irradiating certain containers and showing that we can do it from distances greater than a meter," said Dunn.
Now the task is to simulate real-world conditions in the applications lab to determine whether the technique will work "when there is clutter around, to show that [the real-world environment] won't defeat the technique we've developed. Those results are about six or eight months off," he said.
M2 Technologies and Kansas State have been working on the project since November 2004 under the contract with the Marines for what the military calls stand-off bomb detection. The team's current schedule would have a completed prototype ready for military testing in three or four years.