Forensics

This Tiny Device Can Detect Nuclear Armageddon

The train ride was as uneventful as the dozens of others the man had taken from Washington, D.C., to New York City. He watched the scenery change as he headed north past Baltimore, along the Delaware River to Philadelphia, through Newark, then into the long dark tunnel on the final approach to New York’s Pennsylvania Station. Throughout the trip, the device in his pocket—the size of a portable hard drive, all black, with a single button on the center of one side and a blinking blue LED light above it—remained silent.

After getting off the train, the man moved with the large midday crowd toward the entrance to the subway. On the uptown platform, standing near a dark-haired woman in her late 40s, he felt his pocket vibrate insistently. He looked at his phone: high levels of gamma rays. Technetium-99m. He was the only one who knew. The man, Vincent Tang, is a prominent physicist at DARPA. He and his team have spent the last five years working on Sigma, a program for counteracting nuclear terrorism.

A year ago they launched Sigma+, an expanded system that will identify chemical, biological, and nuclear components, along with explosives, to help law enforcement stop terrorists before they can strike. The major breakthrough is the radioisotope identification device in Tang’s pocket, the D3S, which was built by the British company Kromek. Unlike earlier versions, which were much larger, the D3S fits in your pocket. And at a fraction of the previous price, it can be carried by every police officer, firefighter, EMT, and other emergency-service personnel in a city.