By JONATHAN TENNENBAUM
A desktop-sized nuclear reactor that generates energy without radioactivity – it sounds too good to be true. Indeed, the discovery of a novel form of nuclear energy called “cold fusion,” proclaimed in 1989 by the chemists Martin Fleischmann and Stanley Pons, has long been dismissed by the mainstream scientific community as a case of faulty measurement or even self-delusion.
Some scientists disagreed, however, finding more and more evidence for radioactivity-free nuclear energy generation occurring under the sorts of conditions Fleischmann and Pons had created: in crystalline materials infused with large quantities of hydrogen or its non-radioactive isotope deuterium.
Now a combination of three factors – accumulation of credible experimental results over the ensuing 30-odd years, resolution of some major issues regarding reproducibility and a developing technology base – has brought cold fusion to the threshold of a breakout.
Big players are quietly investing substantial sums into cold fusion research, positioning themselves for what could turn out to be a major game-changer on the global energy scene. Japan and the United States are way ahead.
In Japan, presently the leading nation in this field, the sponsors include Mitsubishi Heavy Industries, Mitsubishi Estate Company, Toyota, Nissan, Tanaka Precious Metals and the Miura Corporation, a major producer of heating equipment.
From the US side Google has become active, sponsoring a multi-university study of cold fusion and reportedly working to recruit promising young scientists to cold fusion research.
Another prominent US investor is Tom Darden (Cherokee Investment Partners, Industrial Heat). It is an open secret, I am told, that Bill Gates, in addition to his work in other aspects of futuristic nuclear technology, is also engaged in this area.
The wave of interest in cold fusion was evident behind the scenes at the 22nd International Conference on Condensed Matter Nuclear Science (abbreviated ICCF-22) in Assisi, Italy, earlier this year.
Condensed matter nuclear physics is the technical name for the new area of science and technology that has emerged over the 30-odd years since the first announcement of cold fusion. This and the following articles provide a non-technical overview of where things stand at the moment.
The background
What did Fleischmann and Pons do in 1989? Put very simply, they used an electric current to force large amounts of deuterium into a bar of palladium metal. After a certain time the bar began to produce more heat than could be attributed to the input energy. In some of their experiments the excess heat continued for days, releasing net amounts of energy hundreds of times larger than could be accounted for by any known chemical reaction.
Fleischmann and Pons concluded that the source must be nuclear fusion reactions – in this specific case, the fusing of pairs of deuterium nuclei to form helium.
Fusion reactions have long been known as the energy source of the sun and also of the hydrogen bomb, mankind’s first and so far only realization of fusion energy on a significant scale.
The biggest problem is that hydrogen nuclei, being positively charged, repel each other. In order to bring them close enough for fusion reactions to occur, one either must compress the hydrogen fuel to practically unrealizable densities or else must cause the nuclei in the fuel to collide with one another at high velocities – velocities equivalent to temperatures of tens of millions of degrees. This, at least, is what conventional nuclear physics tells us.
At the same time, fusion reactions invariably release large amounts of high-energy radiation, which can be deadly to humans and cause materials in the vicinity to become radioactive.
Technologies exist to reach the required temperatures under controlled conditions; but despite billions of dollars of investment into fusion test reactors, the realization of “hot fusion” as a commercially viable energy source still appears distant. We hope that innovative privately-financed projects, now under way, will improve at least the medium-term prospects for hot fusion.
Scientific gamble
Fleischmann and Pons started out with a simple, even naive idea. It is well known that palladium can absorb large amounts of hydrogen. In fact, palladium alloys have been studied as a means of storing hydrogen in hydrogen-powered vehicles.
Moreover the process of electrolysis, familiar to chemists, provides a means to “pump” hydrogen nuclei into palladium with the equivalent of 10,000 or more times ordinary atmospheric pressure. Inside the palladium crystal, hydrogen nuclei are present at high density and also able to move around rather freely.
Simplified scheme of Fleischmann-Pons experiment: an electric current is used to “pump” nuclei of deuterium (D), split off from heavy water (D2O), into a palladium cathode.Could fusion reactions happen? Not in any significant numbers, nuclear physics would appear to tell us; the estimated reaction rates remain almost infinitesimally small.
However, there were reasons to think that nuclei might interact differently, when embedded in a dense crystalline environment, than when they float around in a vacuum. Among other things, the repulsive forces between the hydrogen nuclei might be significantly weakened by the high density of electrons in their crystalline environment. Under such conditions, perhaps, the standard estimates for fusion reaction rates might give the wrong answer.
Fleischmann and Pons decided to give it a try, using deuterium (rather than ordinary hydrogen) on account of its higher reactivity. One can appreciate the incredulity of the scientific community in 1989, when the two scientists announced they had realized nuclear fusion at room temperature – “cold” fusion – in a table-top-sized experiment.
Following the spectacular announcement, scientists around the world rushed to their laboratories to replicate the Fleischmann-Pons results. The result was devastating. In the vast majority of cases – although not all – they found absolutely nothing. Sometimes some sporadic pulses of heat were observed, and sometimes tiny amounts of radiation, but these were mostly attributed to spurious causes or experimental error.
A first-generation cold fusion cell, used for early experiments carried out at a laboratory of the US Space and Naval Warfare Systems Command. Photo: Steven KrivitOnly a minority, including Fleischmann and Pons themselves, continued to believe that the cold fusion phenomenon was real. After some years of controversy, cold fusion was essentially written off by the scientific community. Leading scientific journals stopped accepting research papers on the subject, and government financial support dropped off nearly completely.
It has not helped that alongside real scientists, dubious persons and entities have emerged, attempting to make money at the expense of serious research. In these muddied waters, the concept “cold fusion” came to be associated with “pathological science,” quackery or even fraud.
So why are Google and others now taking such an interest in this supposedly “nonexistent” process? One reason is the fever-pitch of concern over global warming and the resulting demand for CO2-free technologies, prompting governments and private investors to look closely at all potential options, including those in the high risk, high return category.
According to Michael McKubre, a pioneer of cold fusion research and keynote speaker at the ICCF-22 conference, Google had concluded from its studies that so-called renewable energy sources alone could not solve mankind’s energy problem.
Michael McKubre in cold fusion laboratory at SRI Intl. Photo: courtesy Michael McKubreIn terms of economically viable CO2-free power generation, that left only nuclear energy in some form: advanced 4th generation nuclear fission reactors that promise to be safer and cheaper, or hot fusion or . . . cold fusion. Why not take a second look?
30 years in the cold
In the early 1990s a minority of scientists from high-level national laboratories and universities, notably in the US, France, Italy, Japan, India, Russia and China had disagreed with the consensus view on cold fusion.
From their own experiments they became convinced that the phenomena reported by Fleischmann and Pons – while sporadic and maddeningly difficult to reproduce in a reliable manner – were real. They continued to investigate, often risking their careers and reputations in the process.
Meanwhile, a handful of leading theoretical physicists rejected the notion that cold fusion is physically impossible. These included Nobel Prize-winner Julian Schwinger, Peter Hagelstein (made famous by his work on the X-ray laser) and the well-known quantum physicist Giuliano Preparata.
Credit: LoKiLeChThey pointed out that the nuclear processes in the Fleischmann-Pons and related experiments were occurring under conditions that had never been studied carefully by physicists before. When nuclei are embedded at high density in the lattice structure of a crystal, their behavior can change radically. Some basic rules and assumptions of conventional nuclear physics no longer apply. Not only fusion, but also other nuclear reactions might possibly occur.
Some researchers suggested, in fact, that the cause of heat generation and other anomalous phenomena in the Fleischmann-Pons type of experiments might not be conventional fusion reactions between nuclei of hydrogen but some other nuclear process. One possibility is that reactions might involve nuclei of the host material – palladium, for example. (Until such issues are clarified, researchers in this domain mostly prefer to use the inclusive term “low energy nuclear reactions,” abbreviated LENR, instead of cold fusion. For the purposes of this article I shall stick with the popularized term, cold fusion, intended in a generic sense.)
In the subsequent period a vast number of experiments were carried out, not only on setups of the Pons-Fleischmann type, but with a wide variety of other systems in which hydrogen or deuterium nuclei are densely embedded in the crystalline structures of metals. The data base is impressive. Apart from excess heat a whole array of other anomalous phenomena turned up, pointing to nuclear processes of a new type.
Some experiments have revealed faint emissions of radiation, confirming the presence of nuclear reactions, but at extremely low, harmless levels, totally incommensurate with the amounts of heat being produced. Repeatedly evidence was found that the elemental composition of the material had changed during the experiment. Excluding laboratory contamination the only explanation is nuclear transmutation – the transformation of one chemical element into another. Amazing.
Two challenges
Two major challenges have faced cold fusion research since the beginning. First is how to obtain excess heat and other effects in a fully reproducible fashion. It was not enough that these effects had been observed again and again by reputable scientists in laboratories around the world. Without being able to demonstrate cold fusion “on demand” it would hardly be possible to dispel the doubts of the scientific community and to lower the perceived risk among would-be investors.
The second big challenge is to come up with a plausible theoretical explanation for the cold fusion phenomenon: a theory that can be tested experimentally and can serve as a guide for developing cold fusion/LENR and related technologies to the point of commercial application.
Attaining reproducibility has proven to be much, much more difficult than originally thought. The reason, apart from lack of research funds, evidently lies in the complexity of the physical process itself. In my opinion – and judging from the ICCF-22 conference – cold fusion is not some sort of magic bullet that will instantly solve mankind’s energy problems without a commensurate effort in fundamental and applied R&D.
Fortunately, after nearly 30 years of effort, great progress has been made toward defining the necessary conditions for cold fusion to occur, and creating a technology base for future commercial applications.
In my view the existence and reproducibility of cold fusion (or, more broadly, LENR) have now been established beyond any reasonable doubt. Here I mean, more precisely: nuclear reactions generating substantial amounts of heat, realizable on a laboratory scale at moderate temperatures in certain solid-state materials implanted to a high density with deuterium or hydrogen; and releasing at most a negligible amount of radiation.
Having attended the ICCF-22 conference, spoken with researchers and studied relevant technical publications, I do not think an unbiased scientist who looks into the matter closely can come to any other conclusion.
Jonathan Tennenbaum received his PhD in mathematics from the University of California in 1972 at age 23. Also a physicist, linguist and concert pianist, he’s a former editor of FUSION magazine. He lives in Berlin and travels frequently to Asia and elsewhere, consulting on economics, science and technology.
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