Nuclear resonance fluorescence may help
Forget x-ray vision. With superhero-like accuracy, a new detector conceived by MIT professor of physics William Bertozzi ‘53, PhD ‘58, can identify virtually any type of illicit cargo–bombs, nuclear materials, drugs, and more–through bolted doors of solid steel. Bertozzi envisions a future in which the more than 11 million cargo containers moving through U.S. ports annually will pass through data collection stations that determine in real time whether dangerous or unwanted materials are inside; the containers will remain unopened, the vehicles carrying them undelayed. Current inspection methods, which may include x-ray scanning, can sometimes detect the presence of shielded materials but cannot determine their composition.
Bertozzi became interested in detection technology when Pan Am Flight 103 blew up over Lockerbie, Scotland, in 1988; he wondered whether a technique he’d learned about in graduate school, nuclear resonance fluorescence (NRF), could have identified the explosives hidden onboard. NRF can pick out the unique nuclear fingerprint of almost any element by measuring the energy of photons emitted by decaying nuclei. Unlike x-rays, NRF imaging can detect the isotopic composition of a material even when it’s shielded by lead.
Using a process he patented, Bertozzi, along with his colleagues at Passport Systems of Billerica, MA, is creating an NRF-based scanner. In addition to detecting bombs or revealing nuclear materials that could potentially slip into the country disguised as legitimate cargo, the system could also blow the whistle on commercial shippers who illegally try to save on tariffs by declaring that their products contain cheaper materials than they do–say, granite rather than marble.
“This technology, along with other developments by Passport based on research carried out at MIT, could take port security to an unprecedented level,” says Bertozzi, who hopes to introduce a full-scale scanner for sea cargo containers within the next two years. “This technology could fundamentally change our global system for the efficient and reliable shipment of goods in volume between all parts of the world,” he says.