A team of scientists from Yale University, Brookhaven National Laboratory and Brigham Young University has announced they have been unable to duplicate the results of a key experiment in which signs of "cold fusion" were reported.
The team, which began collaboration in August, included BYU physicist Steven E. Jones, who has been conducting cold fusion experiments for years.The scientists sought evidence of large bursts of neutrons as were reported in an experiment involving researchers at BYU and Los Alamos National Laboratory. They also looked in a different experiment for the random emission of only a few neutrons at a time.
They said those results were still being analyzed.
However, the scientists reported finding no large bursts of neutrons, a fusion byproduct.
Bursts, including a much smaller number of neutrons, were observed in control experiments, and the researchers said they were consistent with having originated from cosmic-ray background.
Preliminary results of the collaborative effort were presented this week to a federal Department of Energy Advisory board that concluded Tuesday that no convincing evidence has yet been found to prove that cold fusion exists.
But somewhat surprisingly, the group backed off from some of the more negative comments it had made previously. It changed after examining reports of some new experiments using improved technology, which suggest not all reported cold fusion effects can come from experimental error.
In fact, at the insistence of co-chairman Norman Ramsey, this year's Nobel prize winner in physics, the panel conceded that while no one has proven cold fusion exists, no one has clearly proven that it doesn't either.
Therefore, the panel said it is sympathetic to modest support of additional research to resolve many of the unanswered questions about strange, reported cold fusion effects. But it still recommends against major funding for special new programs or new centers for cold fusion.
Its final version still gave little hope for cheap power from cold fusion, which was first reported by University of Utah researcher B. Stanley Pons and his British colleague, Martin Fleishmann.
It said results of "calorimetric cell" experiments similar to theirs to date "do not present convincing evidence that useful sources of energy will result from the phenomena attributed to cold fusion.
Suggestions for some future experiments included looking for excess heat and fusion products in the same cell, not one or the other - as was recently done by Texas A&M with reports of success.
It also called for cooperative efforts among many groups to try to make cold fusion effects more reproducible.
The BYU-Yale cold fusion collaboration is considered unique because it brought together both believers and critics of cold fusion.
Moshe Gai, an associate professor of physics at Yale who headed the collaborative project, has been highly critical of the work of Pons and Fleischmann, who ignited the fusion controversy last March.
He has said publicly that he has had difficulty verifying the claims of both U. researchers and the experiments of Jones.
Nonetheless, Gai invited Jones to Yale to use one of the most sensitive arrays of neutron detectors in the world.
The neutron detectors at Yale can be shielded with special concrete blocks to drastically reduce the amount of background radiation improving the experimental results, Gai said.
The data was analyzed independently at Yale and Brookhaven, but analysis at Brigham Young is still in progress, the researchers said.
The researchers emphasized that their findings were preliminary, and added they are performing a detailed study of background effects that they said may reveal the origin of conflicting results on reported neutron emission.