Lack of Evidence Fails to Sway Claim on Fusion
Researchers from Texas A & M University on Tuesday stood by their claim that they were observing nuclear fusion in a flask, but they conceded that they were unable to observe a key fusion byproduct that most scientists agree would provide firm proof that fusion is occurring.
Their failure to observe this key byproduct, helium-4, weakened the already shaky underpinnings that have supported the controversial claims of two Utah scientists that they had been able to produce sustained nuclear fusion in a simple electrochemical cell.
Other researchers appearing here at a cold fusion symposium organized by the Department of Energy said they were unable to replicate the Utah scientists’ claims. But a spokesman for the University of Utah, where the phenomenon was discovered, said the two researchers are writing up complete details of their experiments, to be published in two months, that will provide strong new support for their theories.
It was exactly two months ago that chemists B. Stanley Pons of the University of Utah and Martin Fleischmann of the University of Southampton in England stunned the scientific world by claiming that, using a simple electrochemical cell made up of palladium and platinum electrodes immersed in heavy water (water in which each of the hydrogen atoms has been replaced by deuterium, which has an extra neutron), they could get more energy out than they put in.
Their announcement caught the attention of the world because it promised an inexpensive source of large quantities of energy that might eventually free the world of its dependence on fossil fuels.
They reported that deuterium ions were being forced into the palladium electrode, where they fused together, releasing heat in a process similar to that which powers the sun. Pons and Fleischmann claimed that the cell was producing more power than could be accounted for by simple chemical reactions, and that they had observed both neutrons and tritium, the expected debris of a fusion reaction.
But the amount of neutrons and tritium produced was a billionfold less than should have been present if the reported heat did arise from fusion. The Utah researchers accounted for this discrepancy by arguing that they were observing an unusual fusion reaction in which helium-4 was produced rather than the helium-3, tritium and neutrons that are produced in conventional fusion. The helium-4, they said, was being trapped inside the palladium electrode.
At a meeting in Los Angeles two weeks ago, Pons and Fleischmann admitted that their evidence for the presence of neutrons and tritium was faulty, leaving them with no convincing evidence to support the claim that fusion was the source of the heat they observed.
Many researchers who believe that fusion is occurring have thus been pinning their hopes on measurements that would reveal whether helium-4 was present in a palladium electrode. Physicist John Appleby of Texas A & M--a member of the team that was first to report a partial confirmation of Pons and Fleischmann’s result--made the first report of such a measurement here Monday, and his report was negative.
Appleby said that measurements performed by the Atomics International Division of Rocketdyne Corp. in Canoga Park indicated that no helium-4 was present in the palladium electrode used in his experiment. The researchers also found no helium-3 or tritium, which should have been present if conventional fusion was occurring.
Appleby said that the Texas team was disappointed by the failure to find helium, but that their measurements of excess heat in the cells made them confident that a fusion reaction is occurring. He also conceded that the Texas results are not definitive. “There are loose ends all over the place,” he said.
In a separate report, chemist Kevin L. Wolf of Texas A & M reported that his group had obtained evidence indicating the presence of large quantities of tritium and small quantities of neutrons in a cell that produced excess energy. The presence of tritium was confirmed, he said, by researchers from General Motors Corp. and the Los Alamos National Laboratory. His electrodes have not yet been analyzed for helium, he added.
Other researchers noted, however, that if tritium was present, large quantities of neutrons should also have been observed. Their absence, said physicist Richard Crooks of the Massachusetts Institute of Technology, made him “suspicious” of errors in the tritium measurement.
Pons and Fleischmann were invited to attend the symposium but declined. James Brophy, the University of Utah’s vice president for research and development, said they are completing some new experiments and writing up “complete details” of their experiments for publication within two months.
The pair have been roundly criticized for withholding many details of their experimental techniques, making it very difficult for other researchers to replicate their findings.
Brophy also said that the Utah electrodes are now being analyzed by researchers at Johnson & Mathey, the large metals company in England that provided the electrodes, and that they hope to have details available soon, perhaps this week or next.
Brophy also noted that an agreement for cooperative research between Pons and Fleischmann and researchers at Los Alamos, first announced a month ago, was near signing. But he added that because of Pons’ and Fleischmann’s time constraints, it would be “some weeks” before any such joint research could begin.
In a separate report Tuesday, Swedish physicists in Stockholm said they produced a burst of neutron radiation in a room-temperature experiment. The scientists at the Manne Siegbahn Institute for Physics said their method was similar to that used in the experiment of Pons and Fleischmann.
The Swedish researchers said they ran an electrical current between platinum and palladium electrodes immersed in heavy water containing deuterium.
“The results indicate fusion reactions can occur at low temperatures in the electrode material palladium. This gives certain support to Fleischmann’s and Pons’ ideas,” the scientists said.
