Amidst the tens of thousands of spectators at a NASCAR race in New Hampshire last summer, someone or something was radioactive. And a team of emergency workers at the New Hampshire Motor Speedway in Loudon knew just where to find him.
Each of them carried a new kind of radiation monitor, developed by Passport Systems Inc. of Billerica. The SmartShield G300 is about the size of a pack of cigarettes, and like other such monitors, it can quickly detect radiation that might be emitted by a "dirty bomb," or worse, a nuclear weapon.
What SmartShield found that day at the Loudon track wasn't dangerous. The system was able to pinpoint the source of the radiation in the crowd; it was a spectator wearing a radioactive implant used in treating cancer. But the Central New Hampshire Hazardous Materials Team, which was using the race to give SmartShield a trial run, was impressed enough with the results to buy five of the units, at about $8,000 each. The team expects to deploy them at events that draw larger crowds.
"It's the next level of detection and tracking for radiological sources," said Bill Weinhold, chief of the hazardous materials team. "It helps make a venue or special event safer."
Since it was founded in 2002 by Robert Ledoux, a former associate professor of physics at the Massachusetts Institute of Technology, Passport has spent $85 million in federal grants and private investments to develop new ways to spot atomic hazards. SmartShield is the company's first product to go to market.
The G300 is used in conjunction with smartphones. When a detector picks up a potential threat, it sends a wireless warning to the cellphones of other G300 operators, as well as to a central command post. The GPS location chip in smartphones then helps operators pinpoint the source of the radiation.
Passport has a big brother version of the system that will soon be up and running in the Port of Boston , a $16 million scanner for inspecting incoming shipping containers. The SmartScan 3D system is being erected inside a car-wash-sized building at the port's Conley Container Terminal. It uses a giant X-ray machine and a radiation detector to spot nuclear threats and less perilous contraband like illegal drugs, and is expected to go into service this spring.
"Boston will be the safest port in the world," said Passport cofounder and MIT professor William Bertozzi.
A number of companies already make high-energy X-ray machines for scanning shipping containers. One of the industry leaders, American Science and Engineering Inc., is down the road from Passport in Billerica.
Passport says its new approach can identify contraband that other systems may miss. The X-ray scanner generates three-dimensional images of suspicious materials based upon an object's atomic number, a measure of density used by physicists. The primary X-ray scanner can indicate the presence of contraband, from drugs to nuclear material. But it often can't decisively identify a substance. For instance, said Ledoux, cocaine and salt can be hard to tell apart.
So Passport uses a technique pioneered by Bertozzi, called nuclear resonance fluorescence, to re-scan areas of a container that seem especially suspicious. The X-rays cause materials to emit gamma radiation at specific energy levels that correspond to the materials' atomic structure.
The detector measures this radiation to determine what the stuff is made of. The process is too slow to use on an entire container. But scanning a small area takes only a minute or so.
"Cocaine has a certain signature," said Ledoux. "Explosives does. Water. Salt. Vodka." And, of course, uranium. So SmartScan 3D can target not just terrorist threats, but contraband as well. In a country that bans alcohol, such as Saudi Arabia, it could distinguish between Coca-Cola and Johnny Walker Red. Or it could spot an attempt to smuggle untaxed tobacco, a crime that costs the British government about $3 billion a year.
The versatility of SmartScan 3D makes it an easier sell to foreign nations, said Ledoux. And that's just what the US government wants — for cargo to be scanned for threats over there, before it gets here.
Already, US Customs and Border Protection screens about 80 percent of all US-bound containers at their ports of origin, the agency said. Getting SmartScan 3D installed around the world could make those inspections more thorough.
The first of the new machines is going in at the Port of Boston, as part of a major expansion tied to the opening this year of a new, larger Panama Canal.
"We believe this technology will be more effective and more efficient," said port director Lisa Wieland. Boston handled the equivalent of 237,000 20-foot containers last year, and that throughput will rise 3 to 4 percent annually in coming years, as the new canal will let bigger ships reach Boston.
Still, it's best to spot a nuclear weapon well before it gets to a city. And Passport said it is developing a solution for that — a roadside machine that detects nuclear material in a fast-moving car as it zooms past, shoots a photo of its license plate, and notifies authorities. The company said it has built a prototype and will deliver a test unit to the Department of Homeland Security sometime this fall.