One of the biggest concerns in the wake of 9/11 was the potential of terrorists to smuggle radioactive material into the country using maritime shipping containers. As a result, the 9/11 Commission recommended in its report that the government enact legislation requiring that all cargo bound for the U.S. be screened for possible threats. Based on this recommendation, Congress passed a law mandating that all cargo containers be scanned for radioactive materials prior to being allowed entry into the country. Little did lawmakers realize, however, just how much of a logistical nightmare this would be to implement.
One of the reasons that ports around the world have been unable to screen all U.S.-bound cargo for threats is due to the fact that much of the screening technology in use today is not only expensive, but also burdensome to deploy. However, one company has created a scanning technology that could potentially revolutionize the way that cargo containers are screened in the future. Based just outside Washington, D.C. in Chantilly, Va., Decision Sciences International Corporation (DSIC) has created a scanning solution that uses cosmic ray charge particles to determine the density of objects within cargo containers.
“As earth hurdles through space, space is full of things left over from supernova explosions and other events in the cosmos. Those things floating around , when they hit the upper atmosphere we call them cosmic rays, and they sort of blow up the molecules and break them down into their subatomic components, explained Dr. Stanton Sloane, CEO of DSIC. “Two of those particles that result from the cosmic ray interaction are of interest to us; one is called a muon, the other is electrons.
“Muons are very dense, high mass, they travel at nearly the velocity of light and they have very little nuclear interaction as they traverse the atmosphere and materials. As they pass through things they sort of scatter and the amount of scattering is a function of the density of the material. So muons are very good for looking at high density materials. Of course, nuclear threats are very high density and tend to be uranium, plutonium and those sorts of things. The way the system works is we track the muon from above whatever we’re looking at and then again as it comes out of whatever we’re looking at. We look at that angular change, that’s the scattering angle and that correlates very well with the density of the materials.”
Additionally, the machine can also measure how electrons pass through or become absorbed by different materials, giving them the ability to also detect explosives and other types of contraband. “We can use the muons to measure density, we can use the electrons to measure chemistry and if you think of those two things on an XY plot, materials tend to differentiate themselves pretty well in XY space given those parameters,” he added.
Sloane said the images generated by the scanner are reconstructed in the same way that computer tomography works in the medical imaging environments, providing users with a three-dimensional view of the container.
Although the scanning machine itself is relatively simple physically – a network of aluminum tubing that contains no moving parts – the complexity of the system is in the software algorithms the company has developed.
“It’s completely passive; the only energy we need is the cosmic rays, which are raining down on us all the time anyway,” said Sloane. “Therefore, the machine is very reliable, uses very little power, is very easy to maintain and it has no deleterious effects on people, food or animals. You can place it where people work because there is no radiation, so it’s very flexible in its operation concept.”
Because the technology is safe for use around people, containers can be loaded onto a truck and driven directly into the machine without the driver having to exit vehicle. Sloane said the typical time to clear a container where no threat is present is on the order of 35 to 45 seconds.