Cold fusion

This article is about the nuclear reaction. For the computer programming language, see ColdFusion.

File:ColdFusion.jpg

Charles Bennett examines three "cold fusion" test cells at the Oak Ridge National Laboratory, USA

Cold fusion is a term for any nuclear fusion reaction that occurs well below the temperature required for thermonuclear reactions (which occur at millions of degrees Celsius).

Introduction

There are a number of suggested processes by which cold fusion may occur, although currently none of these has been shown to release more energy than is required to sustain the reaction (see breakeven): a requirement for the process to be useful for producing power. This does not rule out other uses, such as for compact, desktop neutron generation.

The term is often used in a more narrow sense: that is, a phenomenon observed in electrolytic cells in which a small (table-top) apparatus near room temperature and standard atmospheric pressure in which it has been suggested that the the fusion of hydrogen (specifically deuterium) atoms into helium occurs.

Additional claims have been made in the cold fusion field in addition to the fusion reaction. For this reason, the terms "Low Energy Nuclear Reactions" and "Condensed Matter Nuclear Science" are also used to describe work in this area.

Nuclear fusion using deuterium (an isotope of hydrogen) yields large amounts of energy, uses an abundant fuel source, and produces only small amounts of radioactive waste. Therefore, a cheap and simple process of nuclear fusion would have great economic impact. As of 2005, however, hot fusion cannot be achieved in a controlled and sustained way, and proven cold fusion methods do not seem to yield more energy than is put into them. If cold fusion in electrolytic cells were shown to work, it might become a cheap and simple means of power generation.

History

Early work

Palladium and titanium have a proven ability to absorb large quantities of hydrogen. Although the distance between hydrogen nuclei suspended in such metals is no less than it is in other situations (such as a molecule of water), it has been suggested that these metals might, by bringing the deuterium atoms close together, catalyze the fusion of deuterium at ordinary temperatures.

The special ability of palladium to absorb hydrogen was recognized in the 19th century. In the late 1920s, two German scientists, Fritz Paneth and Kurt Peters, reported the transformation of hydrogen into helium by spontaneous nuclear catalysis when hydrogen is absorbed by finely divided palladium at room temperature. These authors later acknowledged that the helium they measured was due to background from the air or the glassware they used.

In 1927, Swedish scientist John Tandberg said that he had fused hydrogen into helium in an electrolytic cell with palladium electrodes. On the basis of his work he applied for a Swedish patent for "a method to produce helium and useful reaction energy". After deuterium was discovered in 1932, Tandberg continued his experiments with heavy water. Due to Paneth and Peters' retraction, Tandberg's patent application was eventually denied.

Pons and Fleischmann's experiment

On March 23, 1989, the chemists Stanley Pons of the University of Utah and Martin Fleischmann of the University of Southampton ("P and F") held a press conference and reported the production of excess heat that could only be explained by a nuclear process. The report was particularly astonishing given the simplicity of the equipment, which was just a water electrolysis experiment consisting of a pair of electrodes connected to a battery and immersed in a jar of heavy water (dideuterium oxide). The press reported on the experiments widely, and it was one of the front-page items on most newspapers around the world. The immense beneficial implications of the Utah experiments, if they were correct, and the ready availability of the required equipment, led scientists around the world to attempt to repeat the experiments within hours of the announcement.

The press conference followed about a year of work of increasing tempo by Pons and Fleischmann, who had been working on their basic experiments since 1984. Their collaboration goes back even further than this, however. Pons had been a graduate student of Fleischmann's at the University of Southampton. In 1988 they applied to the U.S. Department of Energy for funding for a larger series of experiments: up to this point they had been running their experiments "out of their pocket".

The term "cold fusion" was coined by Dr Paul Palmer of Brigham Young University in 1986 in an investigation of "geo-fusion", or the possible existence of fusion in a planetary core. The term was then applied to the Fleischmann-Pons experiment in 1989.

The grant proposal was turned over to several people for peer review, including Steven Jones of Brigham Young University. Jones had worked on muon-catalyzed fusion for some time, and had written an article on the topic entitled "Cold Nuclear Fusion" that had been published in Scientific American, July 1987. He had since turned his attention to the problem of fusion in high-pressure environments, believing that fusion in the metallic hydrogen core of Jupiter might be responsible for the higher-than-normal temperatures of that planet. Paul Palmer noted that the same mechanism might explain the high interior temperature of the Earth (hotter than could be explained without nuclear reactions), and the unusually high concentrations of helium-3 around volcanoes, which implied some sort of nuclear reaction within. Jones started studying high-pressure fusion, which he referred to as piezonuclear fusion, by working with diamond anvils; but he had since moved to electrolytic cells similar to those being worked on by Pons and Fleischmann. In order to characterize the reactions, Jones had spent considerable time designing and building a neutron counter, one able to accurately measure the tiny numbers of neutrons being produced in his experiments.

Both teams were in Utah, but did not know of each other's work until the peer review. After that, they met on several occasions to discuss sharing work and techniques. During this time Pons and Fleischmann described their experiments as generating considerable "excess energy", excess in that it could not be explained by chemical reactions alone. If this were true, their device would have considerable commercial value. Jones was measuring neutron flux instead and seems to have considered it primarily of scientific interest, not commercial. In order to avoid problems in the future, the teams apparently agreed to simultaneously publish their results, although their accounts of their March 6 meeting differ.

In mid-March both teams were ready to publish, and Fleischmann and Jones were to meet at the airport on March 24 to both hand in their papers at the exact same time. However Pons and Fleischmann then "jumped the gun," and held their press conference the day before. Jones, apparently furious at being "scooped," faxed in his paper to Nature as soon as he saw the press announcements. The rush to publish perhaps did as much to muddy the field as any scientific aspects.

Within days scientists around the world had started work on duplications of the experiments. On April 10 a team at Texas A&M University published results of excess heat, and later that day a team at the Georgia Institute of Technology announced neutron production. Both results were widely reported on in the press. Not so well reported was the fact that both teams soon withdrew their results for lack of evidence. For the next six weeks competing claims, counterclaims, and suggested explanations kept the topic on the front pages, and led to what writers have referred to as "fusion confusion."

On April 12 Pons received a huge standing ovation during his presentation at the semi-annual meeting of the American Chemical Society. In May, the president of the University of Utah, who had already secured a $5 million commitment from his state legislature, asked for $25 million from the federal government to set up a "National Cold Fusion Institute". On May 1st a meeting of the American Physical Society held a session[1] on cold fusion that ran past midnight; a string of failed experiments were reported. A second session started the next evening and continued in much the same manner. To some degree this reflected a split between the "chemists" and the "physicists", though it also reflected a more general change in opinion during the weeks which passed between the meetings. Skepticism of the cold fusion claims was rising among both chemists and physicists as more experimentalists attempted and were unable to replicate the experiment.

At the end of May the Energy Research Advisory Board (a standing advisory committee in the U.S. Department of Energy) formed a special panel to investigate cold fusion. The report of the panel after five months' study was that there was no convincing evidence for cold fusion, and that such an effect "would be contrary to all understanding gained of nuclear reactions in the last half century." It specifically recommended against any special funding for cold fusion research, but was "sympathetic toward modest support for carefully focused and cooperative experiments within the present funding system". [2]

Both critics and those attempting replications were frustrated by what they said was incomplete information released by the University of Utah. With the initial reports suggesting successful duplication of their experiments there was not much public criticism, but a growing body of failed experiments started a "buzz" of its own. There was considerable speculation that Pons and Fleischmann had withheld key details of the experiment, possibly as a prelude to obtaining a patent; on the other hand, Fleischmann said at a meeting in April that all the necessary details had been given in the published paper. Some claim that if such data had been withheld, the report could not be falsified to the satisfaction of advocates, as advocates could claim failed experiments were missing some unpublished method. A hypothesis that is not falsifiable would be outside the field of modern science. Fleischmann himself has vigorously denied saying anything like this, ever, and there is no statement in his published papers to this effect. Several hundred other researchers have gone on record in peer-reviewed papers claiming that that they have reproduced the effect, and none of them has ever claimed that there are unpublished "secret" methods to the experiment.

By the end of May much of the media attention had faded among the competing results and counterclaims. More significantly, the research effort decreased greatly. The skeptics claim that most attempts at replication failed and none produced definitive results. Cold fusion researchers claim that most experiments conducted by experienced electrochemists did produce positive results, and many of these results had a high signal to noise ratio and thus were definitive. These disagreements continue to the present day.

At this point, many prominent scientists dismissed the claims. On June 26 at MIT, a party was held mocking the research, "A Wake for Cold Fusion." [3] It has also been suggested by some that MIT sought to hastily attack the cold fusion claims to protect their "hot fusion" program, which had already recieved billions in government funding. Cold fusion researchers feel this judgment was premature because it takes months or years to replicate the experiment.

A National Cold Fusion Institute was established by the state of Utah, and it published a large collection of papers showing that cold fusion produces tritium, which is proof that it is a nuclear process. See, for example, Will, F.G., K. Cedzynska, and D.C. Linton, Reproducible tritium generation in electrochemical cells employing palladium cathodes with high deuterium loading. J. Electroanal. Chem., 1993. 360: p. 161. See also [4] [5].

In September 1990, the National Institute published a tally of replications of cold fusion. [6] It included data from 92 research groups in 10 countries, and it listed positive results in five categories: heat, tritium, neutrons, gamma rays and helium-3. Reports came from groups at Los Alamos NL, Oak Ridge NL, Brookhaven NL, Naval Systems San Diego, BARC India, U. Rome, Case Western U., Texas A&M U., Stanford U., U. Minnesota, U. Rome, Hokkaido U. and many other leading laboratories. These replications along with hundreds of others were later published in peer-reviewed journals.

The Fusion/Energy Council of Utah sponsored a careful, in-depth analysis Fleischmann and Pons' data, which was published in 1991. The author confirmed that the excess heat reported in March 1989 is real. [7]

Experimental set-up and observations

Fleischmann and Pons reported more energy coming from their electrolysis cell than they contributed.

In their original set-up, Fleischmann and Pons used a Dewar flask (a double-walled vacuum flask) for the electrolysis, so that heat conduction would be minimal on the side and the bottom of the cell (only 5% of the heat loss in this experiment). The cell flask was then submerged in a bath maintained at constant temperature to eliminate the effect of external heat sources. They used an open cell, thus allowing the gaseous deuterium and oxygen resulting from the electrolysis reaction to leave the cell (with some heat too). It was necessary to replenish the cell with heavy water at regular intervals. For the temperature observations to be meaningful the cell must be kept at a uniform temperature. Rather than using a mechanical method of stirring, sparging with the generated D₂ gas was done to equalize the temperature "when necessary"; however, the efficacy of this method of maintaining the cell at a uniform temperature would later be disputed. Special attention was paid to the purity of the palladium cathode and electrolyte to prevent the build-up of material on its surface, especially after long periods of operation.

The cell was also instrumented with a thermistor to measure the temperature of the electrolyte, and an electrical heater to generate pulses of heat and calibrate the heat loss due to the gas outlet. After calibration, it was possible to compute the heat generated by the reaction.

A constant current was applied to the cell continuously for many weeks, and heavy water was added as necessary. For most of the time, the power input to the cell was equal to the power that went out of the cell within measuring accuracy, and the cell temperature was stable at around 30 °C. But then, at some point (and in some of the experiments), the temperature reportedly rose suddenly to about 50 °C without changes in the input power, for durations of two days or more. The generated power was calculated to be about 20 times the input power during the power bursts. Eventually the power bursts in any one cell would no longer occur, and the cell was turned off.

Pons and Fleischmann also initially reported that a cell was generating 2.45 MeV neutrons at a rate three times the natural background rate. There was, however, no equipment directly measuring neutron energies, and this report was based on a mistaken inference from a gamma-ray spectrum. The most spectacular result they reported was that in one cell most of the electrode melted and part of it vaporized, destroying the cell and the fume hood enclosing it.

In the months after the initial report went public, a physicist colleague of Pons at the University of Utah, Michael Salomon, was invited into Pons' laboratory. In the five week period he and his research group observed the cells, no fusion products were detected. Pons stated that none of the cells were actively producing the excess heat at the time those observations were taking place, except during one two-hour period during which the detection equipment was unable to function because of a power failure. As neutron irradiation would produce small amounts of ²⁴Na in the detector, Salomon quickly performed an analysis for that product, and found no amount consistent with power production of more than one microwatt. When Salomon and his co-workers had published their results in the journal Nature, each of them received a letter from attorney C. Gary Triggs, declaring that the "paper as published was untenable" and that it should be "voluntarily retracted." Triggs had, he said, been instructed by his clients "to take whatever action is deemed appropriate to protect their legal interests and reputations." Salomon and other scientists, perceiving this as an unprecedented threat against open scientific controversy, rejected the claims categorically and angrily; later, the threats were largely withdrawn.

Continuing efforts

There are currently a number of people researching the possibilities of generating power with cold fusion. Scientists in several countries continue the research, and meet at the International Conference on Cold Fusion (see Proceedings at [8]).

The generation of excess heat has been reported by

• Michael McKubre, director of the Energy Research Center at SRI International,
• Richard A. Oriani (University of Minnesota, in December 1990), [9]
• Robert A. Huggins (at Stanford University in March 1990),[10]
• Y. Arata (Osaka University, Japan),
• S. Szpak, Mosier-Boss, et al. (SPAWAR Naval Research Laboratory in 2004),
• M. Miles and K.B. Johnson (Naval Air Warfare Center Weapons Division). [11]
• Violante et al. (ENEA Frascati, U. Rome, ENEA Casaccia) report excess heat with laser triggering in 4 out of 5 experiments, as well as weak x-rays and transmutations [12] [13]

among others. In the best experimental set-up, excess heat was reported in 50% of the experiment reproductions. Various fusion ashes and transmutations were reported by some scientists.

Dr. Michael McKubre thinks a working cold fusion reactor is possible. Dr. Edmund Storms, a former scientist with The Los Alamos National Laboratory in New Mexico, maintains an international database of research into cold fusion.

In March, 2004, the U.S. Department of Energy (DOE) decided to review all previous research of cold fusion in order to see whether further research was warranted by any new results. The review document[14] submitted to the DOE by the group of scientists who had requested a new review process states that "The experimental evidence for anomalies in metal deuterides, including excess heat and nuclear emissions, suggests the existence of new physical effects". It recognizes indirect evidence in support of the D + D → ⁴He + 23.8 MeV (heat) reaction, although the measurement of ⁴He quantity is imprecise. This review document was submitted to peer review, to a mixed but predominantly negative response. Of the 18 reviewers, "Two-thirds of the reviewers commenting on Charge Element 1 did not feel the evidence was conclusive for low energy nuclear reactions, one found the evidence convincing, and the remainder indicated they were somewhat convinced. Many reviewers noted that poor experiment design, documentation, background control and other similar issues hampered the understanding and interpretation of the results presented." [15] Most cold fusion researchers agree with this evaluation, but they point out that design and documentation suffer from lack of funding. Most experiments are conducted on a shoestring by a retired professors. A few experiments, such as the ones at Mitsubishi Heavy Industries, [16] the Japan Synchrotron Radiation Research Institute Spring8 facility and the Italian National Laboratories [17] are properly funded (with millions of dollars), and the DoE peer review group agreed that this work is well designed.

In 2004, Mike McKubre of SRI International reported that the effect is highly dependent on the packing of deuterium in the electrode. He reports that with a deuterium/palladium ratio of 1:1 (i.e., one deuterium atom for each palladium atom) excess heat is consistently produced, whereas at a ratio of 9:1 only 2 experimental runs in 12 show excess heat. Skeptics as of 2005 claim that the effect is not reproducible, and that if ever is made reproducible it should be possible to make experiments that will show definitely whether the heat is due to chemical effects, cold fusion, or some form of energy storage. Cold fusion researchers say that by 1990 the effect was reproducible enough to eliminate any scientific doubt about its existence (although not reproducible enough for practical applications), and chemical effects and storage are ruled out (see "Energy source vs. power store," below.)

As of 2005 the excess heat, tritium and other phenomena remain unexplained, and skeptics claim the reported energy output has never been associated with an equivalent amount of fusion products of any kind. Cold fusion researchers disagree, pointing out that the heat is always associated with helium-4 production in the same ratio as plasma fusion (~24 MeV per helium atom). Skeptics say that although there may be a genuine physical phenomenon at work, the hypothesis that it involves nuclear fusion is unproven and widely seen as unlikely, whereas cold fusion researchers say that any effect which produces 24 MeV per helium atom, x-rays, tritium and so on is -- by definition -- a fusion reaction. After sixteen years of investigation, the skeptics and the cold fusion researchers remain as far apart in their views as they were in March 1989, but study continues and the researchers remain hopeful that the phenomenon will be understood eventually.

Analysis of the attempts to replicate Pons and Fleischmann's results

The following section is for a short analysis of the experiments that attempted to replicate Pons and Fleischmann's results, such as:

• The length of the experimental cycles
• How close they were to the devices and procedures Pons and Fleischmann used
• Does the raw data appear to be interpreted or reported correctly?

Lewis, et al - (reported 17 Aug 89) Williams, et al - (reported 23 Nov 89) Amoco - (19 March 1990)

Arguments in the controversy

Here are the main arguments in the controversy:

Bias against cold fusion and rushed replication experiments

One of the arguments in favor of those supporting the cold fusion claims is the belief that many of the experiments attempting to reproduce were carried out with a negative bias. Skepticism isn't unfounded, but bias is unscientific since it can lead scientists to unintentionally misinterpret experimental results. Most scientific discoveries now taken for granted have gone against opposition that held back the acceptance of the discoveries, sometimes for generations.

It has also been suggested, as a matter of opinion of some individuals, that some of the experiments done by others to replicate the results might have been rushed, possibly due to excitement in some cases, or in others because primary focus was seeking negative results. For instance, MIT had placed a lot of resources into their own tokamak research that has yet to generate more power than it uses. Acceptance of "cold fusion" would have led to the death of their research program, which had already recieved billions in government funding. Eugene Mallove, an MIT-trained engineer, noticed that the graph from the MIT experiment's baseline concealed a small amount of anomalous heat (See Wired: What if Cold Fusion is Real?).

The experiments that are most commonly criticized are those done by Caltech, the Harwell Laboratory in England, and MIT.

Experimental design

One of the main criticisms of the cold fusion claims by skeptics is that the experimental design made it very difficult to get reliable and repeatable results. In particular, skeptics claim there are many different ways by which the experiment can exchange energy with its environment, and the book-keeping necessary to establish whether or not there is any net energy gain has been criticized for being difficult to do correctly and prone to error. Cold fusion researchers say this claim is a violation of the second law of thermodynamics which proves that heat can only leave the system. They say that most of the calorimeters used in these experiments were developed between 1780 (Lavoisier's ice calorimeter) and 1840 (Joule's isoperibolic calorimeter), so they are well understood and not prone to error. They say the difficulty with reliability and repeatability is caused by the materials and electrochemistry, not by the instruments or experimental design.

Skeptics claim that not only could energy be exchanged with the environment, but perhaps what triggered the reaction had something to do with the conditions of the original location, such as unmeasured ultrasonics or electromagnetic energy, that could have lead to the measured release of energy. So although the claims could be correct, the lack of a closed environment makes it hard to reproduce the same affect. Cold fusion researchers point out that most experiments are, in fact, closed and shielded (electrochemically and physically), so it is not likely that an external trigger would have an effect, but they agree that triggering by lasers, a heat pulse, a change in current, ultrasonic generators in the cell and various other methods are effective. These have been widely used.

Skeptics say that their objection could be overruled either by creating an experiment which is less subject to errors, or by looking for signs of fusion which have nothing to do with excess heat. But they claim that neither of these strategies has produced conclusive evidence that this cold fusion process exists. Cold fusion researchers say that by 1991 there was definitive nuclear evidence other than excess heat. They point to tritium far above background levels, helium-4 commensurate with a plasma fusion reaction (~24 MeV of heat is found per helium atom), x-rays, gamma-rays, neutrons and heavy element transmutations. These effects have been measured many times with different instrument types in different laboratories, so systematic errors are ruled out. Regarding the skeptical claim that the experiments are "subject to error" cold fusion researchers point out that they have written thousand of papers but the skeptics have not published papers showing errors in this literature, and the instruments and techniques are conventional and have been in use for decades, so it is not likely there are unknown aspects of their operation which could produce giant errors, such as 101 watts of excess heat (2 to 3 times input) continuously for 30 days. [18]

Reproducibility of excess heat

While some researchers claimed to have reproduced the excess heat with similar, or different, experiments, they could not do it with predictable results, and many others failed to measure excess heat.

However, it is not uncommon for a new phenomenon to be difficult to control, and to bring erratic results. For example, attempts to repeat electrostatic experiments (similar to those performed by Benjamin Franklin) often fail due to excessive air humidity. That does not mean that electrostatic phenomena are fictitious, or that experimental data are fraudulent. On the contrary, occasional observations of new events, by qualified experimenters, can in some cases be the essential steps leading to recognized discoveries. At the same time, it is also the case that some experiments are hard to do, and it is easy to come up with results which look anomalous but which are in fact the result of experimental design deficiencies. This seldom applies to cold fusion however, because even though the effect is complicated and difficult to produce, many of the tests for it are simple and based on old and well established techniques. For example, it is diffiult to imagine how an autoradiograph showing x-rays could look anomalous but not be. [19]

Skeptics say reproducibility of the result will remain the main issue in cold fusion research until an experiment is designed which is fully reproducible by following a clear recipe, and which preferably generates power continuously rather than sporadically and does so in a way that cannot be attributed to experimental defects. Cold fusion researchers agree that reproducibility is a problem, but the results cannot be attributed to experimental defects, and they say that detailed recipes were published by 1996 by Storms and others [20] and that most positive experiments produce continuous rather than sporadic heat. These recipes call for expert skills and months of painstaking labor to prepare and test cathodes before performing an experiment, but they are no more demanding or less clear than the procedures experts follow in other fields such as semiconductor manufacturing, metallurgy, or constructing tokamak plasma fusion reactors.

Cold fusion researchers feel that the reproducibility issue is overblown. After 1990, cold fusion was more reproducible than most semiconductor types were in 1954, or cloning is today. (The success rate for cloning is 0.1 to 3% [21].) Yet no one doubts that semiconductors and cloning exist. By 1991 Bockris reported that about a third of his cold fusion cells produced tritium, and over 100 other reports of tritium had been published, [22] yet skeptics still claim that tritium has not been reproduced.

The unexpected ratio of decay products

We know that cold fusion is a nuclear effect because it generates hundreds of thousands of times more heat than any chemical process can, and yet there are no chemical changes or ash in the cell. We also know that it is a nuclear fusion reaction because it produces decay products which are specific only to fusion. These products have been measured in hundreds of experiments. They include neutrons, tritium, x-rays, gamma-rays and helium. However, the ratio of neutrons and tritium produced by cold fusion is roughly 11 orders of magnitude lower than it is for plasma fusion. According to plasma fusion theory, if the excess heat were generated by the fusion of 2 deuterium atoms, the most probable outcome would be the generation of either a tritium atom and a proton, or a ³He and a neutron, but these probabilities do not apply to cold fusion. The ratio of neutrons to heat is so different, if a 1-watt Fleischmann-Pons experiment produced a neutron flux as intense as a 1-watt plasma fusion reaction does, it would be lethal, yet the cold fusion reactions are safe. Even in March 1989, it was obvious that cold fusion -- assuming it exists -- must be radically different from plasma fusion. Presumably, this is is because conditions in a metal lattice are very different from conditions in the sun, or as theorist J. Schwinger said: "the circumstances of cold fusion are not those of hot fusion," Schwinger and others proposed theories to explain the low ratio of neutrons to heat. [23] [24]

Cold fusion experiments have shown that helium-4 is the dominant by-product of the reaction. The ratio of helium-4 to the heat has been shown to be the same as plasma fusion: 24 MeV per helium atom. (In plasma fusion, less than 1% of the nuclear products are seen as helium-4, but the energy from this 1% is 24 MeV per atom.) [25] [26][27][28] A collection of related papers on helium evolution is here.

It should also be noted that none of the other processes that are sometimes called cold fusion have these theoretical issues. In particular, the Farnsworth-Hirsch Fusor is sold commercially as a source of neutrons, and evidence for some of the other forms of fusion comes not from excess heat but from the decay products.

This experimental result could be and has been explained by arguing that the current understanding of physics is incorrect, but this leads to other problems. It is more likely that the current understand of physics is incomplete, because highly loaded metal deuterides have not been studied in detail before.

Current understanding of physics

In addition to the lack of decay products, current understanding of nuclear fusion shows that the following explanations are not adequate:

• Nuclear reaction in general: The average density of deuterium in the palladium rod seems vastly insufficient to force pairs of nuclei close enough for fusion to occur according to mechanisms known to mainstream theories. The average distance is approximately 0.17 nanometers, a distance at which the attractive strong nuclear force cannot overcome the Coulomb repulsion. Actually, deuterium atoms are closer together in D₂ gas molecules, which do not exhibit fusion.

• Fusion of deuterium into helium 4: if the excess heat were generated by the fusion of two deuterium atoms into ⁴He, a reaction which is normally extremely rare, gamma rays and helium would be generated. Again, insufficient levels of helium and gamma rays have been observed to explain the excess heat, and there is no known mechanism to explain how gamma rays could be converted into heat.

Disagreement with existing theory does not in itself prove that the experiment is wrong. For example, both superconductivity and Brownian motion were observed (and could be reproduced by anyone with suitable equipment) long before they were explained; high-temperature superconductivity has yet to be explained, despite the industrial availability of such superconductors. On the other hand, one can also cite observations of polywater and N-rays. Only four or five researchers claimed they reproduced these effects, and they claimed the signal to noise ratio was very low. [1] [2]. In contrast, hundreds of researchers worldwide claim they have reproduced cold fusion, often at very high signal to noise ratios. Excess heat has been measured at sigma 50 to 100, and tritium and helium between 60 and 1 million times background. [3] Roughly 500 papers were published about polywater at the peak [2], but most were theory and only a handful claimed positive experimental results, whereas over 3,000 papers on cold fusion have been published. [4]

Although requiring exotic or unknown physics does not rule out the existence of a process, it does drastically increase the level of evidence needed to establish a process, while at the same time making it much harder to perform experiments to verify that the process exists. Requiring exotic or unknown physics increases the skeptic's suspicion that the underlying cause of the experimental results lies in errors of experimental design or misinterpretation of results, and causes the scientific community to be skeptical of marginal results and demand unambiguous demonstrations of a process.

Cold fusion researchers disagree with this point of view. They say the results are not marginal; they are unambigous (with high signal to noise ratios). They also say that the experiments have been repeated hundreds of times with many different instrument types, and published in rigorous peer-reviewed journals. This was not, however, the consensus of the December 2004 DoE peer review. As noted above only a third of the reviewers were "somewhat convinced."

At the same time, lack of an adequate theory makes it much harder to design experiments to create those results. Without such theory, it is much more difficult to predict what could happen in a given situation and design experiments to test those predictions. For example, based on standard nuclear theory, one would expect that the amount of heat generated would depend on the concentration of heavy water or the ratio between deuterium and tritium. These relationships do not appear to hold consistently, and the inability to establish any definite relationships between the energy output of the experiments and experimental inputs leads to skepticism that what is being observed has anything to do with fusion.

Most people still define "cold fusion" as a phenomenon in which "heat is produced from fusion of isolated deuterium nuclei at ordinary temperatures." Skeptics say it is not difficult to be convinced that such phenomenon is impossible. This has nothing to do with chemically assisted nuclear anomalies in condensed matter reported in recent years. This refers, for example, to emission of neutrons, at rates too small to release measurable amounts of heat. It also refers to generation of helium and tritium, to unusual isotopic ratios, and to nuclear transmutations in deuterized metals. The second DOE review (December, 2004) recognizes "a number of basic science research areas that could be helpful in resolving some of the controversies in the field, two of which were: 1) material science aspects of deuterated metals using modern characterization techniques, and 2) the study of particles reportedly emitted from deuterated foils using state-of-the-art apparatus and methods."

Cold fusion researchers agree that based on conventional theory alone, it is indeed "not difficult to be convinced that such phenomenon is impossible," but they point out that cold fusion is based on experiment, not theory. They say the experiments demonstrate that the effect produces thousands of electron-volts of energy per atom, tritium, and other nuclear effects. While they agree that the number of neutrons is orders of magnitude lower than theory predicts, they do not think this is a valid reason to reject the experimental results. They feel that if there is a conflict between theory and replicated experimental results, the experiments should overrule theory.

1. Klotz, I., The N-Ray Affair. Scientific American, 1980. 242(5): p. 168-175.

2. Franks, F., Polywater. 1981, Cambridge, MA: MIT Press.

3. Clarke, B.W., et al., Search for 3He and 4He in Arata-Style Palladium Cathodes II: Evidence for Tritium Production. Fusion Sci. & Technol., 2001. 40: p. 152.

4. 3,324 documents are listed in the LENR-CANR.org index as of December 2005, but some are newspaper and magazine articles. Roughly a third are from peer-reviewed journals.

Energy source vs. power store

Some skeptics claim that while the output power is higher than the input power during the power burst, the power balance over the whole experiment does not show significant imbalances. Since the mechanism under the power burst is not known, one cannot say whether energy is really produced, or simply stored during the early stages of the experiment (loading of deuterium in the Palladium cathode) for later release during the power burst. A "power store" discovery would yield only a new, and very expensive, kind of storage battery, not a source of abundant cheap fusion power.

Cold fusion researchers disagree. They point out that in all experiments in which excess heat has been recorded, the overall balance has been positive; there are no instances in which a heat deficit was recorded first, that would balance out the excess. In most bulk palladium electrochemical experiments, an incubation period of 10 to 20 days is followed by continuous excess heat production, which often continues longer than the incubation period. "Isothermal Flow Calorimetric Investigations of the D/Pd System" shows typical examples. ^[29] Since the excess heat is easily detected, at a high signal to noise ratio, and the initial deficit would have to be even larger than the excess that follows, it would easily be detected. Researchers also point out that most cells produce far more energy than any known chemical storage mechanism would permit. Chemical processes store (or produce) at most 12 eV per atom of reactant, whereas many cold fusion experiments have produced hundreds of eV per atom of cathode material, and some have produced ~100,000 eV per atom.

Furthermore, many researchers, notably Kainthla et al. ^[30] and McKubre et al. ^[31] have conducted careful inventories of chemical fuel and potential storage mechanisms in cold fusion cells, and they have found neither fuel nor spent ash that could account for more than a tiny fraction of the excess heat. Since many cells have released large amounts of energy, a megajoule or more, this chemical fuel would have to be present in macroscopic amounts. In fact, in many cases the volume of ash would greatly exceed the entire cell volume. These issues of energy storage and chemical fuel hypotheses have been discussed in the literature exhaustively. See, for example, "A Response to the Review of Cold Fusion by the DoE", section II.1.2.^[32]

Other kinds of fusion

This article focuses on the Fleischmann-Pons effect in electrolytic cells. This effect has also been reported using other methods of forming hydrides including gas loading, electromigration and ion implantion.

A variety of other methods are known to effect nuclear fusion. Some are "cold" in the strict sense as no part of the material is hot (except for the reaction products), some are "cold" in the limited sense that the bulk of the material is at a relatively low temperature and pressure but the reactants are not, and some are "hot" fusion methods that create macroscopic regions of very high temperature and pressure.

• Fusion with low-energy reactants:
  • Muon-catalyzed fusion is a well established and reproducible fusion process that occurs at ordinary temperatures. It was studied in detail by Steven Jones in the early 1980s. It has not been reported to produce net energy. Because of the energy required to create muons, their 2.2 µs half-life, and the chance that muons will bind to new helium nuclei and thus stop catalyzing fusion, net energy production from this reaction is not believed to be possible.
• Fusion with high-energy reactants in relatively cold condensed matter: (Energy losses from the small hot spots to the surrounding cold matter will generally preclude any possibility of net energy production.)
  • Pyroelectric fusion was reported in April 2005 by a team at UCLA. The scientists used a pyroelectric crystal heated from −34 to 7 °C, combined with a tungsten needle to produce an electric field of about 25 gigavolts per meter to ionize and accelerate deuterium nuclei into an erbium deuteride target. Though the energy of the deuterium ions generated by the crystal has not been directly measured, the authors used 100 keV (a temperature of about 10⁹ K) as an estimate in their modeling.[33] At these energy levels, two deuterium nuclei can fuse together to produce a helium-3 nucleus, a 2.45 MeV neutron and bremsstrahlung. This experiment has been repeated successfully, and other scientists have confirmed the results. Although it makes a useful neutron generator, the apparatus is not intended for power generation since it requires far more energy than it produces. [34] [35] [36] [37]
  • Antimatter-initialized fusion uses small amounts of antimatter to trigger a tiny fusion explosion. This has been studied primarily in the context of making nuclear pulse propulsion feasible. This is not near becoming a practical power source, due to the cost of manufacturing antimatter alone.
  • In sonoluminescence, acoustic shock waves create temporary bubbles that collapse shortly after creation, producing very high temperatures and pressures. In 2002, Rusi P. Taleyarkhan reported the possibility that bubble fusion occurs in those collapsing bubbles. As of 2005, experiments to determine whether fusion is occurring give conflicting results. If fusion is occurring, it is because the local temperature and pressure are sufficiently high to produce hot fusion.
• Fusion with macroscopic regions of high energy plasma:
  • "Standard" "hot" fusion, in which the fuel reaches tremendous temperature and pressure inside a fusion reactor, nuclear weapon, or star.
  • The Farnsworth-Hirsch Fusor is a tabletop device in which fusion occurs. This fusion comes from high effective temperatures produced by electrostatic acceleration of ions. The device can be built inexpensively, but it too is unable to produce a net power output. These devices have a valid use however, and are commercially sold as a source of neutrons. The ion energy distribution is generally supposed to be nearly mono-energetic, but Todd Rider showed in his doctoral thesis for Massachusetts Institute of Technology that such non-Maxwellian distributions require too much recirculating power to be practically sustainable.

Cold fusion in fiction

• The Saint, a 1997 film starring Val Kilmer who plays a spy (Simon Templar) hired to steal a cold fusion formula.
• Final Exam, an Outer Limits episode.
• The Skylark of Space, a 1928 novel.
• Chain Reaction, a 1996 film starring Keanu Reeves
• Command & Conquer: Generals, a 2002 video game in which cold fusion reactors supply power to a mobile American military.
• In one episode of Stargate SG-1 (Prisoners) a woman on a prison planet uses what Carter thinks is cold fusion to power the gate for a manual dial-out.
• Starcraft A Sci-fi Strategy game that features the use of cold fusion in the transportation.

See also

• List of energy topics : list identifies articles and categories that relate to energy.
• Alchemy : early protoscientific practice combining elements of chemistry, physics, astrology, art, semiotics, metallurgy, medicine,and mysticism.
• Pathological science : term to describe ideas that would simply not "go away", long after they were given up on as wrong by the majority of scientists in the field.
• Protoscience : any new area of scientific endeavor in the process of becoming established.
• Transmutation : the conversion of one object into another.
• List of holy grails

Patents

• U.S. patent 5,635,038 - Patterson, "System for electrolysis and heating of water". June 3, 1997.

As of 2001, however, the US patent office has been rejecting patent applications whose sole utility is the production of excess heat by cold fusion alone. The rejections have been based on the fact that applicants have not been able to provide reproduceable results. See MPEP 2107.01 for a more complete discussion of the "utility" requirement for a patent (i.e. 35 USC 101).

Journals

• Handel, Peter H., "Subtraction of a New Thermo-Electrochemical Effect From The Excess Heat, and the Emerging Avenues to Cold Fusion", Proceedings: Fourth International Conference on cold Fusion, EPRI, Palo Alto, California, pp. 7-1 to 7-8.

References

General

• Krivit, Steven ; Winocur, Nadine. The Rebirth of Cold Fusion. Los Angeles, CA, Pacific Oaks Press, 2004 ISBN 0976054582.
  • A book documenting the cold fusion saga from a "pro-cold fusion" perspective, backed with research and interviews from cold fusion researchers around the world.
• Beaudette, Charles. Excess Heat: Why Cold Fusion Research Prevailed. Concord, N.H.: Infinite Energy Press, 2000. ISBN 0967854814.
  • A more recent scientific account defending the view that cold fusion research prevailed.
• Close, Frank E..Too Hot to Handle: The Race for Cold Fusion. Princeton, N.J. : Princeton University Press, 1991. ISBN 0691085919; ISBN 0140159266.
• Huizenga, John R. Cold Fusion: The Scientific Fiasco of the Century. Rochester, N.Y.: University of Rochester Press, 1992. ISBN 1878822071; ISBN 0198558171.
  • The above two books are other skeptical examinations from the scientific mainstream. Huizenga was co-chair of the DOE panel set up to investigate the Pons/Fleischmann experiment.
• Mallove, Eugene. Fire from Ice: Searching for the Truth Behind the Cold Fusion Furor. Concord, N.H.: Infinite Energy Press, 1991. ISBN 1892925028.
  • An early account from the pro-cold-fusion perspective.
• Mizuno, Tadahiko ; Mallove, Eugine ; Rothwell, Jed. Nuclear Transmutation: The Reality of Cold Fusion. Concord, N.H.: Infinite Energy Press, 1998. ISBN 1892925001.
• Park, Robert L. Voodoo Science: The Road from Foolishness to Fraud. New York: Oxford University Press, 2000. ISBN 0195135156.
  • Park gives an account of cold fusion and its history from the skeptical perspective.

Energy source vs power store

• ^ McKubre, M.C.H., et al. Isothermal Flow Calorimetric Investigations of the D/Pd System. in Second Annual Conference on Cold Fusion, "The Science of Cold Fusion". 1991. Como, Italy: Societa Italiana di Fisica, Bologna, Italy, http://lenr-canr.org/acrobat/McKubreMCHisothermala.pdf
• ^ Kainthla, R.C., et al., Eight chemical explanations of the Fleischmann-Pons effect. J. Hydrogen Energy, 1989. 14(11): p. 771.
• ^ McKubre, M.C.H., et al., Development of Advanced Concepts for Nuclear Processes in Deuterated Metals. 1994, EPRI.
• ^ Storms, E., A Response to the Review of Cold Fusion by the DoE. 2005, Lattice Energy, LLC, http://lenr-canr.org/acrobat/StormsEaresponset.pdf

External Articles

Related links

Papers and reports

• "Electrochemically Induced Nuclear Fusion of Deuterium" - the original paper from 1989
• "Cold Fusion Research" - Energy Research Advisory Board report (November 1989)
  • "Conclusions and recommendations" section of the report
• U.S. DOE 2004 Cold Fusion Review - U.S. Department of Energy review of 15 years of cold fusion experiments
• Additional information on the DOE 2004 Cold Fusion Review. This page includes the full text of the reviewer's comments, which is not available on the DOE pages, plus links to the full text of 42 of the papers submitted by cold fusion researchers to the review panel. (The list of all 130 submitted papers can be found here.)
• Response to the DOE/2004 Review of Cold-Fusion Research - C. Beaudette's critique of the DOE 2004 Cold Fusion Review
• Cold Fusion overview - John Coviello provides an introductory synopsis for new encyclopedic entry at PESWiki.com.
• Cold Fusion - An Objective Assessment - by Dr. Edmund Storms, a review of the experimental results (December 2001; 233 references, including 34 studies reporting anomalous energy using the Pons-Fleischmann method)
• A Student's Guide to Cold Fusion - by Edmund Storms. A 55 pages introduction to the subject.
• Overview of BARC Studies in Cold Fusion. - P.K. Iyengar (Atomic Energy Commission, India) and M. Srinivasan (Bhabha Atomic Research Centre) review some of the major research in India.
• A "Cold Fusion primer", in English and Italian

Journals and publications

• Infinite Energy - one of the original periodicals dedicated to cold fusion and new energy
• New Energy Times - site that focuses on the latest advances in the field of cold fusion
• Cold Fusion Times - quarterly journal about cold fusion

Websites and repositories

• Low Energy Nuclear Reactions — Chemically Assisted Nuclear Reactions - information and links from pro-cold fusion research, and an online library of over 400 full-text papers from the peer-reviewed literature and conference proceedings
• Britz's cold nuclear fusion bibliography - an overview and review of almost all available publications about cold nuclear fusion
• Cold Fusion — 16 Years and Heating Up - directory of cold fusion resources compiled by FreeEnergyNews.com
• L. Kowalski's web site - a collection of commentaries on cold fusion research from a physics teacher
• International Society for Condensed Matter Nuclear Science - website of the ISCMNS
• JL Naudin's web site - the CFR project, a High Temperature Plasma Electrolysis based on the Tadahiko Mizuno work from the Hokkaido University (Japan)

News

In 1989

• Elation Should Be Tempered Until Jury Has Examined Experiments The Financial Post May 1, 1989
• "PFC results said to deal blow to fusion claims" - an MIT Tech article about work in their Plasma Fusion Center debunking early cold fusion claims
• "Physicists Debunk Claim Of a New Kind of Fusion" - Science article on the controversy

Later news

• Whatever Happened to Cold Fusion? The American Scholar, Fall 1994
• What If Cold Fusion Is Real? Wired, November 1998
• Whatever happened to cold fusion? Physics World, March 1999
• The War Against Cold Fusion - What's really behind it? SF Gate - May 17, 1999
• ICCF-11 Overview With Links to Presentations International Society for Condensed Matter Nuclear Science November 2004
• U.S. review rekindles cold fusion debate Nature - Dec. 2, 2004 (Nature had not published anything about cold fusion for years prior to this article.)
• The 2005 Cold Fusion Colloquium May 21, 2005 - Public gathering of cold fusion researchers at MIT in Cambridge, MA
• ICCF-12 Annoucement November 27 - December 2, 2005, Shin Yokohama Prince Hotel in Yokohama city, Japan
• Cold-Fusion Believers Work On, Even as Mainstream Science Gives Them the Cold Shoulder Salt Lake City Weekly - October 20, 2005