Scientists experiment with imaginative ways to fight terrorism

“This is a Semtex sausage,’’ says Carey, as he pinches the pink plastic explosive long favored by terrorist groups.

On his table lay a green Teletubbies doll stuffed with C-4 military explosives, a leather sandal with a high-explosive shoe insert, an Entenmann’s cake covered in an explosive compound that looks like white frosting, and other deadly devices Carey and his colleagues have built. None has a detonator, so all are safe.

“We let our imaginations go wild,’’ explains Carey. “The types of improvised explosive devices are endless.’’

So are possible solutions, at least in theory. That’s where the Transportation Security Laboratory comes in. Scientists here dream up ways that an enemy might slip a weapon or a bomb onto a plane, and then try to build defenses to counter the danger. The work is part cutting-edge science, part Maxwell Smart.

Staffers have experimented by exploding more than 200 bombs on junked airliners. They also have filled a warehouse with nearly 10,000 abandoned pieces of luggage.

“We build bombs in them’’ and run them through airport-style screening machines, says Susan Hallowell, the lab’s director. If the bomb escapes detection, technicians try to figure out how to catch it next time. “We call it the art of bagology.’’

Most important, the lab evaluates and certifies all the equipment purchased from outside vendors to search, sniff, or scan passengers and their luggage at some 450 US airports.

Colin Drury, distinguished professor emeritus of engineering at the State University of New York at Buffalo, calls the lab “one of the best in the world for the kind of work they do.’’

“They think broadly and have new ideas, and maybe 90 percent don’t work,’’ he says. “But that’s OK, as long as 10 percent do.’’

About 125 chemists, physicists, engineers, and others work at the lab, at the edge of the Atlantic City International Airport.

It is an environment filled with painful reminders of how terrorism has changed the world.

Hallowell, 56, joined the lab as an analytic chemist when it first opened following the 1988 terrorist bombing of Pan Am Flight 103 over Lockerbie, Scotland. The lab still keeps a mock-up of the Semtex-filled boom box that brought the jet down, killing 270 people.

She was named director shortly after the 2001 attacks on New York’s World Trade Center and the Pentagon that turned the backwater lab into a national priority. Its budget has seesawed over time, but it now is about $45 million a year.

Like Q in James Bond films, Hallowell clearly enjoys the unusual tools - and the dark humor - of her profession. She takes a woman’s shiny black pump off a shelf. It hides an inert explosive in the heel.

“I’ve always liked this shoe,’’ she says. “It’s my size.’’

The lab’s efforts to detect hidden threats increasingly compete with the need to protect travelers’ privacy As a result, the lab is caught in the latest controversy involving the Transportation Security Agency, its chief customer.

The TSA will deploy 150 backscatter imaging machines at checkpoints in major airports.

The devices use a low-level X-ray beam that produces a three-dimensional image of each passenger, including every bump, bulge, and private body part.

Such invasive imaging is “a virtual strip search,’’ the American Civil Liberties Union and other privacy groups assert.