Claims by two scientists that they have produced fusion at room temperature set off a chain reaction across the country Friday as scientists in dozens of laboratories began preparing to try to duplicate the experiment.

"A lot of people around the country will be trying to do it," said nuclear astrophysicist Charles A. Barnes of the California Institute of Technology.The flurry of activity followed a dramatic - and highly controversial - announcement Thursday at the University of Utah in Salt Lake City. B. Stanley Pons, chairman of the university's department of chemistry, and Martin Fleischmann, professor of electrochemistry at the University of Southampton, England, said they produced fusion energy from a simple table-top device.

They also said they had produced more energy than it took to run their apparatus, which would amount to a breakthrough that no one else in the world has been able to achieve despite the expenditure of many billions of dollars over three decades.

The announcement was met with what a spokesman for the Michigan Institute of Technology described as "extreme skepticism," because the experiment goes against the current understanding of the physics of fusion and it has not been verified by other scientists. However, Pons and Fleischmann picked up some early support Friday.

Edward Teller, director emeritus of the Lawrence Livermore Laboratory in California and a legendary pioneer in fusion research, said the experiment "sounds extremely promising."

"Initially, my opinion was that it could never happen," Teller said. "I'm extremely happy now because I see a very good chance that I was completely wrong."

Scientists at the Livermore facility met with Teller Friday to map out their strategy for trying to repeat the experiment.

Some other scientists, however, treated the Utah claims with incredulity, partly because the scientists announced their findings through a press conference instead of publishing their work in a professional journal where it would be subject to peer review.

"That makes you suspicious," said Robert G. Sachs, professor emeritus of chemistry at the University of Chicago and a former director of the Argonne National Laboratory, near Chicago.

Sachs recalled similar claims nearly two decades ago from three independent research teams in the United States, the Soviet Union and China. U.S. researchers thought they had achieved fusion at room temperature with a similar technique, but Sachs said it turned out that the apparatus had somehow picked up high voltage from some other nearby experiment, causing some fusion to occur in a very inefficient system.

Pons and Fleischmann have done their experiment repeatedly over the past five years, sometimes for stretches of 100 hours, and associates say they are not likely to have made that kind of mistake.

"Stan Pons and Martin Fleischmann are both brilliant," said Charles Martin, an electrochemist at Texas A&M University. "I know them well."

He described them as highly professional, dedicated scientists who would not have publicized their results had they not been totally satisfied that they are right.

"A lot of people say this doesn't make a lot of sense, but a lot of science doesn't make sense initially," he added.

Asked if he expected to duplicate the experiment, he responded, "We're trying it right now."

He said it will be several days, at least, before he has any results. Martin and other scientists are expecting to have some difficulty repeating the experiment because - as several scientists said Friday - they have to base their experiments on newspaper accounts because that has been their only source of information. Pons and Fleischmann are expected to publish a paper on their work in about a month in the British journal Nature.

Some scientists also expressed a bit of envy.

"Suppose you were designing jet airplanes and then you suddenly heard on CBS news that somebody had invented an anti-gravity machine. That's the way we feel," said Ian H. Hutchinson, a nuclear fusion researcher at Massachusetts Institute of Technology. "And, of course, we're skeptical," he told the Associated Press.

An Idaho laboratory announced Friday it was conducting experiments to confirm the Utah reports.

Caltech's Barnes said the results claimed by the Utah team should be fairly easy to check.

"A few thousand dollars will get you a few quarts of heavy water (water enriched in a form of hydrogen called deuterium) and a few hundred dollars will get you the palladium and platinum."

Pons and Fleischmann wrapped a coil of platinum around a small cylinder of palladium and inserted it into a glass jar filled with heavy water. They said that when they applied a small current to the apparatus the deuterium in the heavy water concentrated in the palladium tightly enough to produce fusion. Most fusion research projects are far more elaborate, using reactors that heat the fuel to hundreds of millions of degrees, or powerful lasers that cause pellets of fuel to implode.

Meanwhile, other scientists warned that reproducing the experiment may have some hazards.

John Soures, a fusion researcher at the University of Rochester, said that if the Utah experiment actually produced four watts of power, as claimed by the two scientists, it would have emitted a dangerous level of radioactive neutron particles.

"It would require some shielding to prevent people in the vicinity from being irradiated," he said. "You wouldn't put it out in the open."