Stanford Lab Adds Support to Table-Top Fusion Claims
As the race to produce fusion in a flask heated up around the world Tuesday, Stanford University revealed experiments that indicate nuclear fusion, and not some kind of chemical reaction, is the most likely explanation for heat generated by a table-top apparatus at the University of Utah.
The Stanford announcement came on the heels of discovery of helium-4 in the Utah experiment, a discovery that fits perfectly with a growing number of theories that explain why it might be possible to achieve fusion at room temperature with a simple experiment. Less than a month ago, nearly all the experts thought that suggestion was preposterous.
Meanwhile, scientists in both Czechoslovakia and Italy claimed Tuesday to have achieved cold fusion, although the Italian experiment is so different from the Utah project that it only deepens the mystery.
Flood of Support
It all added up to a flood of support for two beleaguered electro-chemists, B. Stanley Pons of the University of Utah and Martin Fleischmann of the University of Southampton, England. The two scientists announced at a March 23 press conference in Salt Lake City that they had achieved fusion in a flask and produced more energy than their experiment consumed.
That astonishing claim sent scientists around the world rushing to their laboratories to try to duplicate the experiment because--if true--it holds the promise of providing a cheap, inexhaustible source of energy.
Many physicists have argued that it is essential to conduct a “control” experiment, which would reveal whether the heat detected in the Utah experiment comes from a chemical reaction or nuclear fusion. That could be done by running parallel experiments, one with “heavy water,” which contains a heavy isotope of hydrogen, called deuterium, and one with ordinary water.
The Utah team claims that their experiment caused atomic nuclei of deuterium, called deuterons, to pack into a palladium electrode and fuse, producing energy in the form of heat.
If so, an experiment with heavy water should produce heat, but the same experiment using ordinary water should not.
Series of Experiments
A Stanford team of seven researchers, led by Robert A. Huggins, professor of materials science, has conducted a series of control experiments and found that the experiment with regular water produced no heat. But the one with heavy water produced heat “comparable to that reported by Pons and Fleischmann,” Huggins said.
The experiment was repeated at least five times in side-by-side versions--always with the same result.
The purpose of the dual experiments was to “negate the possibility” of the heat being caused by a chemical reaction, Huggins said in a telephone interview.
“We are seeing quite a difference” between the two experiments, Huggins said. “The thermal effects are real.”
No attempt was made to measure radiation, which would have been expected from any fusion process before the Pons and Fleischmann experiment. The experiment apparently produces so few radioactive byproducts that they are almost impossible to measure.
Huggins stopped short of saying the work at Stanford confirms that nuclear fusion is the only explanation for the heat generated by the experiment, but it clearly shows that deuterium plays a key role in whatever is going on.
“We think the result is significant,” he said.
The Stanford research was conducted in the university’s solid state ionics laboratory of the department of materials science and engineering.
Huggins said he can understand why many other laboratories are having trouble replicating the experiment.
“It sounds simpler than it really is,” he said. “It’s easy for people to do bad experiments.”
The success at Stanford adds fuel to a fire that, for many scientists, actually peaked the day before when two chemists at the University of Utah revealed that they had carried their colleague’s experiment a step further. Cheves Walling, a widely respected chemist who pioneered the study of nuclear reactions, and fellow chemist John Simons put one of Pons’ heat-generating experiments in their mass spectrometer and determined that the experiment was producing helium-4.
Helium-4 is the most common form of helium, but it is extremely rare as a byproduct of deuterium fusion, and its presence in the palladium used in the Pons-Fleischmann experiment is extremely significant, Walling said.
From the beginning, physicists have been skeptical of the Utah claims because the experiment should have produced far more neutrons than were detected by Pons and Fleischmann. That suggested to physicists that something other than fusion was taking place.
Theories Gaining Acceptance
But the production of helium-4 explains the lack of neutrons because that process would produce relatively few neutrons, according to theories that are now gaining wide acceptance throughout the scientific community.
“I think it’s the last nail in the coffin,” pioneering nuclear physicist Robert Cornog said of the discovery of helium-4 in the electrode. “It’s almost as exciting as the original announcement.”
Even before Monday’s announcement by Walling and Simons, Jeff W. Eerkens, a physicist with Isotope Technologies of Los Angeles, had already submitted a paper to Science magazine saying that the production of helium-4 would explain why the experiment produced heat but an insignificant number of neutrons. Pons had suggested the same thing about three weeks ago.
Eerkens, who has held a wide range of posts in the nuclear industry, said in an interview that helium-4 is being produced instead of helium-3 because of something he calls the “wall effect.”
When helium is produced in nature through fusion, as in the case of the sun and all other stars, helium-4 spends its excess energy by releasing a neutron or a proton and then becomes the lighter isotope, helium-3, or its radioactive sister, tritium. That is what physicists had also expected to see in all fusion reactions created by man.
However, in the palladium electrode used in the Utah experiment, the deuterons are packed tightly into the crystal lattice of the palladium itself, Eerkens said. When deuterons fuse in the palladium, he said, the helium-4 bangs into “the wall” of palladium.
“The wall absorbs the energy,” he said, which is then released as heat. The helium-4 remains trapped in the lattice, although it occasionally turns into helium-3 and releases a neutron.
Eerkens and a number of others, including Peter Hagelstein of the Massachusetts Institute of Technology, have argued that only the presence of helium-4 could explain excess heat and low emissions of neutrons.
When Walling and Simons set out to see if the Pons-Fleischmann experiment had produced helium-4, they had one advantage over everyone else: They had access to the same experiments used by Pons.
They chose an electrode that was already producing heat, and while it was running they checked to see what elements it was producing. They found helium-4, Walling said, and in amounts consistent with the heat that was being generated.
That development may not be as exciting to lay persons as some other parts of this ongoing scientific drama, but for dozens of theorists trying to come up with an explanation for what is going on, it was stunning news.
“It’s a major advancement,” said Cornog, who decades ago took part in some of the earliest experiments in nuclear physics at UC Berkeley.
In one of the more peculiar developments Tuesday, Italian scientists announced that they had created nuclear fusion in a small apparatus that is very different from the Utah experiment.
Pons and Fleischmann used an electric current to separate the deuterons from the heavy water and force them into the palladium. But the Italian experiment did not even use electrochemistry, according to physicist Francesco Scaramuzzi, 60, head of a team from the state-run Atomic Energy Authority at Frascati, near Rome.
Unlike the Pons-Fleischmann results, the Frascati experiment emitted a substantial number of neutrons, which Scaramuzzi and other Italian scientists said could only have come from a cold fusion reaction.
“The results of the Frascati experiment leave us extremely convinced that fusion was obtained,” Scaramuzzi said in a Rome press conference. “From the scientific point of view, we are confident.”
In the Italian experiment, shavings of titanium were placed in a small tube containing deuterium gas. Like palladium, titanium also lends itself to the compaction of deuterons.
The Italians did not reveal exactly how the experiment was conducted, but Scaramuzzi said it was repeated several times and emitted several hundred neutrons per second--still far below what would have been expected prior to Pons and Fleischmann but, if true, high enough to indicate nuclear fusion.
Meanwhile, the Czechoslovak news agency CTK said that a group of physicists and mathematicians from Bratislava’s Comenius University had also achieved nuclear fusion at room temperature in an experiment conducted Monday, but further details were not available. That brings to five the number of nations with scientists claiming to have duplicated the Pons-Fleischmann experiment.
A THEORY TO EXPLAIN SIMPLE FUSION
In normal deuterium fusion, two deuterium ions (each of which has one proton and one neutron) fuse together to form a highly energetic helium-4 ion (which has two protons and two neutrons). To get rid of the excess energy, the excited helium-4 normally ejects either a neutron (leaving behind a helium-3 ion) or a proton (leaving behind a tritium ion), either of which is equally likely. Physicists have been skeptical about Pons’ and Fleischmann’s results because they have not seen large numbers of neutrons, which should be present if conventional fusion is occurring.
Now, however, theorists are saying that the helium-4 is so tightly constrained in the palladium electrode that it gets rid of all its excess energy by transferring heat to the electrode. Only rarely does it break down and release a neutron. Proof that this pathway occurs is the detection of significant quantities of helium-4 in used electrodes.