Scotch Tape

For those of us who play with tape to much, this is really disturbing news. I gotta start worrying about cancer of the fingers. From the New York times:

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From a Strip of Scotch Tape, X-Rays
By KENNETH CHANG
Published: October 23, 2008

In a tour de force of office supply physics, researchers at the University of California, Los Angeles, have shown that it is possible to produce X-rays by simply unrolling Scotch tape.

Next step: nuclear fusion.

“We’re going to do that,” said Seth J. Putterman, a professor of physics at U.C.L.A. “I think it will work.”

But first, X-rays.

In the current issue of the journal Nature, Dr. Putterman and his colleagues report that surprisingly fierce flows of electrons were unleashed as the tape was unpeeled and its gooey adhesive snapped free of the surface. The electrical currents, in turn, generated strong, short bursts of X-rays — each burst, about a billionth of a second long, contained about 300,000 X-ray photons.

“Some kind of microscopic lightning effect,” Dr. Putterman said.

The scientists even demonstrated that the X-rays were bright enough to take an X-ray of a finger.

That does not mean that tape dispensers on office desks are mini X-ray machines. So far, the phenomenon has been observed only when the tape is unpeeled in a vacuum. Something about air — perhaps moisture — short-circuits the X-rays.

The work is not unprecedented. In 1939, scientists demonstrated that peeling tape emits visible light – an easy experiment anyone can conduct in a closet. But visible light photons have only about one-10,000th the energy of an X-ray photon.

Russian scientists reported as far back as 1953 that they had detected X-rays from tape. “But as far as I can tell, no one ever believed them,” Dr. Putterman said. “It was a big surprise to discover this deep dark corner of past research.”

All of the experiments were conducted with Scotch tape, manufactured by 3M. The details of what is occurring on the molecular scale to generate high-energy photons are not known, the scientists said, in part because the Scotch tape adhesive remains a trade secret.

Other brands of clear adhesive tapes also gave off X-rays, but with a different spectrum of energies. Duct tape did not produce any X-rays, Dr. Putterman said. The scientists have not yet tested masking tape.

The research opens up the possibility of looking for similar X-ray emissions from composite materials as they fatigue. Such materials, increasingly used in airplanes and automobiles, are stronger and lighter than many metals, but they do not show the visible weaknesses that metals do before breaking.

The tape phenomenon could also lead to simple medical devices using bursts of electrons to destroy tumors. The scientists are looking to patent their ideas.

And finally, there’s the possibility of nuclear fusion. If the energy from the breaking adhesive could be directed away from the electrons to heavy hydrogen ions implanted in modified tape, the ions would accelerate fast enough so that when they collided, they could fuse together and give off energy — the same process that lights the sun.