Cold fusion

Cold fusion cell at the US Navy Space and Naval Warfare Systems Center San Diego (2005)

Cold fusion is the name for effects supposed to be nuclear reactions occurring near room temperature and pressure using relatively simple and low-energy-input devices. When two light nuclei are forced to fuse, they form a heavier nucleus and release a large amount of energy.

Cold fusion is the popular term used to refer to what is properly called "low energy nuclear reactions" (LENR), part of the field of "condensed matter nuclear science" (CMNS). Cold fusion was brought into popular consciousness by the controversy surrounding the Fleischmann-Pons experiment in March 1989. Their claims, if true, would lead to revolutionary energy production technology, but they conflict with established nuclear reaction physics. Early attempts to replicate the effect were unsuccessful, after which cold fusion gained a reputation as an example of pathological science.

There are now nearly 200 published reports of anomalous power - mostly in non-mainstream publications, with a few in peer-reviewed journals. Panels organized by the U.S. Department of Energy (DoE), the first in 1989 and the second in 2004, did not find the evidence convincing enough to justify a federally-funded program, though they did recommend further research.

Overview

The electrolysis cell

When water is electrolyzed in a closed cell surrounded by a calorimeter, all energy transfer can be accounted for using the theories of electricity, thermodynamics and chemistry: the electrical input energy, the heat accumulated in the cell, the chemical storage of energy and the heat leaving the cell all balance out. When the cathode is made of palladium and heavy water is used instead of light water, the same conservation of energy should be observed.

What Fleischmann and Pons said was that the heat measured by their calorimeter significantly exceeded their expectations in some cases. They calculated a power density over 1 W/cm³ based on the volume of the cathode, a value too high to be explained by chemical reactions alone. They concluded that the effect must be nuclear, although they lacked evidence for it.

Others have tried to replicate their observations. Many failed, but some succeeded, using a variety of setups. They reported high power densities in peer reviewed journals such as the Japanese Journal of Applied Physics and the Journal of Electroanalytical Chemistry. In the most recent review of the field by the DoE, some researchers believed that the experimental evidence was sufficient to establish the scientific validity of the excess heat effect. Others rejected the evidence, and the panel was evenly split on the issue. This was a significant change compared to the 1989 DoE panel, which rejected it entirely.

The search for products of nuclear fusion has resulted in conflicting results, leading two thirds of the 2004 DoE reviewers to reject the possibility of nuclear reactions. In 2006, Pamela Mosier-Boss and Stanislaw Szpak, researchers in the U.S. Navy's Space and Naval Warfare Systems Center San Diego, reported evidence of high-energy nuclear reactions concentrated near the probe surface. Based on this work, two other teams have reported similar findings at the American Physical Society meeting of March 2007 (sessions A31 and B31).

One reason for many to exclude a nuclear origin for the effect is that current theories in physics cannot explain how fusion could occur under such conditions. However, the lack of a satisfactory explanation cannot be used to dismiss experimental evidence. Many theories have thus been proposed, in a continuing effort to explain the reported observations.

The US Patent Office accepted a patent in cold fusion in 2001. Still, current knowledge of the effect, if it exists, is insufficient to expect commercial applications soon. The 2004 DoE panel identified several areas that could be further studied using appropriate scientific methods.

Experimental evidence

Measurement of excess heat

File:SzpakIRcameraviews.jpg

An infrared picture of hot spots on the cathode of a cold fusion cell. Presented by Szpak at ICCF10

The cold fusion researchers presenting their review document to the 2004 DoE panel on cold fusion said that the possibility of calorimetric errors has been carefully considered, studied, tested and ultimately rejected. They explained that, in 1989, Fleischmann and Pons used an open cell from which energy was lost in a variety of ways: the differential equation used to determine excess energy was awkward and subject to misunderstanding, and the method had an error of 1% or better. Recognizing these issues, SRI International and other research teams used a flow calorimeter around closed cells: the governing equations became trivial, and the method had an error of 0.5% or better. Over 50 experiments conducted by SRI International showed excess power well above the accuracy of measurement. Arata and Zhang observed excess heat power averaging 80 watts over 12 days. The researchers also said that the amount of energy reported in some of the experiments appeared to be too great compared to the small mass of the material in the cell for it to be stored by any chemical process. Their control experiments using light water never showed excess heat. While Storms says that light water is an impurity that can kill the effect, Miley and others have reported low energy nuclear reactions with light water.

When asked about the evidence for power that cannot be attributed to an ordinary chemical or solid state source, the 2004 DoE panel was evenly split. Many of the reviewers noted that poor experiment design, documentation, background control and other similar issues hampered the understanding and interpretation of the results presented to the DoE panel. The reviewers who did not find the production of excess power convincing said that excess power in the short term is not the same as net energy production over the entire time of an experiment, that all possible chemical and solid state causes of excess heat had not been investigated and eliminated as an explanation, that the magnitude of the effect had not increased after over a decade of work, and that production over a period of time is a few percent of the external power applied and hence calibration and systematic effects could account for the purported effect.

Other reported evidence of heat generation not reviewed by the DoE included the detection of infrared hot spots (see picture), the detection of mini-explosions by a piezoelectric substrate, and the observation of discrete sites exhibiting molten-like features that require substantial energy expenditure.

Nuclear products

A CR-39 detector showing possible nuclear activity in cold fusion experiments at SSC San Diego.

For a nuclear reaction to be proposed as the source of energy, it is necessary to show that the amount of energy is related to the amount of nuclear products. When asked about evidence of low energy nuclear reactions, twelve of the eighteen members of the 2004 DoE panel did not feel that there was any conclusive evidence, five found the evidence "somewhat convincing" and one was entirely convinced.

If the excess heat were generated by the conventional fusion of two deuterium atoms, the most probable outcome, according to current theory, would be the generation of either tritium and a proton, or a ³He and a neutron. The level of protons, tritium, neutrons and ³He actually observed in the Fleischmann-Pons experiment had been higher than current theory predicted, but well below the level expected in view of the heat generated, implying that these reactions cannot explain it.

If the excess heat were generated by the hot fusion of two deuterium atoms into Helium, a reaction which is normally extremely rare, ⁴He and gamma rays would be generated. Miles et al. reported that ⁴He was indeed generated in quantities consistent with the excess heat, but no studies have shown levels of gamma rays consistent with the excess heat. Current nuclear theory cannot explain these results. Researchers are puzzled that some experiments produced heat without ⁴He. Critics note that great care must be used to prevent contamination by helium naturally present in atmospheric air.

Although there appears to be evidence of anomalous transmutations and isotope shifts near the cathode surface in some experiments, cold fusion researchers generally consider that these anomalies are not the ash associated with the primary excess heat effect.

In 2006, nuclear activity was demonstrated by the use of standard nuclear track detectors made of CR-39. Photographs show scarring of the plastic disks, consistent with high energy nuclear radiation. The intensity and pattern of the scarring appears to rule out anomalous sources such as background radiation as the cause. A project has been set up to facilitate its independent replication.

Reproducibility of the result

The cold fusion researchers presenting their review document to the 2004 DoE panel on cold fusion said that the observation of excess heat has been reproduced, that it can be reproduced at will under the proper conditions, and that many of the reasons for failure to reproduce it have been discovered. Despite the assertions of these researchers, most reviewers stated that the effects are not repeatable.

In 1989, the DoE panel said: "Even a single short but valid cold fusion period would be revolutionary. As a result, it is difficult convincingly to resolve all cold fusion claims since, for example, any good experiment that fails to find cold fusion can be discounted as merely not working for unknown reasons." While repeatability is critical for commercial applications, independent reproduction is the criterion used in the scientific method.

Cold fusion supporter Julian Schwinger said that it is not uncommon to have difficulty in reproducing a new phenomenon that involves ill-understood macroscopic control of a microscopic mechanism. As examples, he gave the onset of microchip studies, and the discovery of high-temperature superconductivity.

Theory

Main article: Condensed matter nuclear science

Cold fusion's most significant problem in the eyes of many scientists is that current theories describing conventional "hot" nuclear fusion cannot explain how a cold fusion reaction could occur at relatively low temperatures, and that there is currently no accepted theory to explain cold fusion. The 1989 DoE panel said: "Nuclear fusion at room temperature, of the type discussed in this report, would be contrary to all understanding gained of nuclear reactions in the last half century; it would require the invention of an entirely new nuclear process", but it also recognized that the lack of a satisfactory explanation cannot be used to dismiss experimental evidence.

Cold fusion observations are contrary to the conventional physics of the fusion of 2 deuterium nuclei in three ways :

• the Coulomb barrier cannot be overcome in cold fusion apparatus : because nuclei have a positive charge, they repel each other. To fuse, they need to come closer than two femtometers, so that the attractive nuclear force gets larger than the electrostatic repulsion. However, bringing the nuclei so close together requires an energy on the order of 10 MeV (2 pJ) per nucleus, whereas the energies of chemical reactions are on the order of several electronvolts only. It is hard to explain where the required energy would come from in room-temperature matter, or how it could be concentrated locally. Nuclei are so far apart in a metal lattice that it is hard to believe that the distant atoms could somehow facilitate the fusion reaction. The average distance between nuclei in Palladium is approximately 0.17 nanometers. Deuterium nuclei are closer together in D₂ gas molecules, which do not exhibit fusion.

• the standard nuclear fusion products are not observed: if the excess heat is generated by the fusion of deuterium nuclei, conventional fusion reactions would usually produce either a tritium nucleus and a proton, or a ³He nucleus and a neutron. The amount of neutrons, tritium and ³He measured from the Fleischmann-Pons experiment is well below what would be expected from the branching fractions of conventional fusion reactions generating the same amount of heat. While Miles et al. reported that the fusion of 2 deuterium nuclei into ⁴He was observed in quantities consistent with the excess heat, insufficient levels of gamma rays have been observed. Furthermore, the branching fraction of ⁴He in conventional fusion is 10⁷ times lower than that of a tritium and a proton.

• there is no known mechanism that would release the energy as heat instead of radiation within the relatively small metal lattice. Robert F. Heeter said that the direct conversion of fusion energy into heat is not possible because of energy and momentum conservation and the laws of special relativity.

Cold fusion theoreticians have thus proposed explanations of the reported observations based on other mechanisms than plain D-D fusion.

To address the Coulomb barrier issue, some researchers propose that nuclei absorb neutrons, not deuteriums; because neutrons have no charge, they are not affected by the Coulomb barrier. For example, John C. Fisher has proposed a theory based on hypothetical polyneutrons. Mills has proposed a theory based on hydrino, which assumes that the electron in a hydrogen atom can reach an energy level below the ground state permitted by quantum mechanics. Both theories are contrary to conventional physics.

To address the nuclear products issue, and because transmutations products have been found, it has been suggested that fusion occurs between one or more deuterium and palladium, and is followed by a fission of the resulting nucleus. The observed heat is difficult to reconcile with the observed transmuted products though. Others propose multi-body interactions: the following reaction, if proven to exist, would not generate gamma rays: D+D+D+D -> ⁸Be -> 2 ⁴He. Mitchell Swartz and others have theorized that the lower angular momentum of less energetic, cooler deuterons might affect the initial conditions required and the branching ratios of fusion reactions.[67]

To address the conversion to heat issue, researchers have proposed a Mossbauer-like effect: in the Mossbauer effect, the recoil energy of a nuclear transition is absorbed by the crystal lattice as a whole, rather than by a single atom. However, the energy involved must be less than that of a phonon, on the order of 30 keV (50% chance of phonon excitation), compared with 23 MeV in nuclear fusion

Alan Widom and Lewis Larsen use conventional quantum mechanics to explain all 3 issues. They propose that heavy electrons form on metallic hydride surfaces, that these electrons react with the protons of deuterium to form low momentum neutrons, that these neutrons are absorbed by surrounding nuclei, and that these nuclei are transmuted by beta decay. They explain why slow neutrons are absorbed so quickly, and how one gamma photon caused by the beta decay is converted to a large number of infrared and X-ray photons by super-heavy electrons, and thus to heat. They do not explain how the energy required to form the neutrons accumulates in one location, in apparent violation of the second law of thermodynamics, and why radioactive elements with long half-life are not produced.

Many other theories have been proposed, in a continuing effort to explain the reported observations..

Possible commercial developments

Cold fusion's commercial viability is unknown. The evidence for the excess heat effect is not accepted by a majority of scientists. If it exists, the effect would have to be theoretically understood before it could be scaled up for commercial use. Cells are too small by orders of magnitude to be commercially viable (with typically less than a gram of material). Researchers have not yet invented methods to prevent cathodes from deteriorating, cracking, and melting during the experiments. Additionally, all cold fusion experiments have produced power in bursts lasting for days or weeks, not for months as would be needed for many commercial applications. Moreover, the aggregate ratio of power output to input for all cold fusion experiments reproduced in peer-reviewed scientific literature has been far too small to suggest any kind of commercial viability.

Cold fusion researchers say that the excess heat is generated in tiny spots that are very hot, and if these hot spots can be created at a high rate, there is no reason to believe that the process could not be scaled up to megawatt levels. This could have a substantial economic impact, and could have advantages over plasma fusion (which has also not yet been developed for practical application) because it produces little ionizing radiation and can be scaled to small devices. Skeptics, however, say that commercial applications have been promised many times, but never delivered. In 1995, Clean Energy Technology, Inc (CETI) demonstrated a 1-kilowatt cold fusion reactor at the Power-Gen '95 Americas power industry trade show in Anaheim, CA. They obtained several patents from the USPTO. As of 2006, no cold fusion reactor has been commercialized by CETI or the patent holders.

Companies publicly said to be developing cold fusion devices at some point include: Energetics Technologies Ltd. (Israel), D2Fusion, JET Thermal Products, Clean Energy Technologies, Inc. of Sarasota Florida (CETI), Lattice Energy, LLC and Coolescence, LLC. There are also some private cold fusion commercialization efforts that are rumored to be ongoing.

History

Early work

The idea that palladium or titanium might catalyze fusion stems from the special ability of these metals to absorb large quantities of hydrogen (including its deuterium isotope). The hydrogen or deuterium disassociate with the respective positive ions, but remain in an anomalously mobile state inside the metal lattice, exhibiting rapid diffusion and high electrical conductivity. The special ability of palladium to absorb hydrogen was recognized in the nineteenth century by Thomas Graham.

In 1926, two German scientists, F. Paneth and K. 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 retracted their report, acknowledging that the helium they measured was due to background from the air.

A year later, Swedish scientist J. 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.

Events leading to the announcement

In the 1960s, Fleischmann and his team started investigating the possibility that chemical means could influence nuclear processes. Quantum mechanics says that this is not possible , and he started research projects to illustrate inconsistencies of quantum mechanics, and the need to use quantum electrodynamics instead. By 1983, he had experimental evidence leading him to think that condensed phase systems developed coherent structures up to 100 nanometres in size, which are best explained by quantum electrodynamics. Impressed by the observation of "cold explosion" by Percy Williams Bridgman in the 30's, his team went on to study the possibility that nuclear processes would develop in such coherent structures.

In 1988, Fleischmann and Pons applied to the US Department of Energy for funding for a larger series of experiments; up to this point they had been running their experiments "out-of-pocket."

The grant proposal was turned over to several people for peer review, including Steven E. 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 in July 1987. He then turned his attention to the problem of fusion in high-pressure environments, believing it could explain the fact that the interior temperature of the Earth was hotter than could be explained without nuclear reactions, and by unusually high concentrations of helium-3 around volcanoes that implied some sort of nuclear reaction within. At first he worked with diamond anvils on what he referred to as piezonuclear fusion, but then moved to electrolytic cells similar to those being worked on by Fleischmann and Pons. 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. His team got 'tantalizingly positive' results early January 1989, and they decided in early February to publish their results.

Both teams were in Utah, USA and met on several occasions to discuss sharing work and techniques. During this time, Fleischmann and Pons described their experiments as generating considerable "excess energy", which could not be explained by chemical reactions alone. If this were true, their device would have considerable commercial value, and should be protected by patents. 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 had agreed to meet at the airport on the 24th to send their papers at the exact same time to Nature by FedEx. However Fleischmann and Pons broke that apparent agreement - they submitted a paper to the Journal of Electroanalytical Chemistry on the 11th, and they disclosed their work in the 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.

Reactions to the announcement

The press reported the experiments widely, and it was on the front-page of 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.

On April 10, 1989, Fleischmann and Pons published their 8-page "preliminary note" in the Journal of Electroanalytical Chemistry. The paper was rushed, very incomplete and contained a clear error with regard to the Compton edge on the gamma spectra, leading some to conclude that the gamma spectra must be fake.

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 in the press. However, both teams soon withdrew their results for lack of evidence. For the next six weeks, additional competing claims, counterclaims, and suggested explanations kept the topic on the front pages, and led to what some journalists have referred to as "fusion confusion."

On April 12, Pons received a standing ovation from about 7,000 chemists at the semi-annual meeting of the American Chemical Society. Pons was sharing the platform with Harold Furth of the Princeton Plasma Physics Laboratory, who asked whether Pons had compared his results against a control, by replacing the heavy water in his apparatus with ordinary water - Pons said that he had not, but that it seemed like a good idea. He subsequently tried the experiment and reported that he "did not get the baseline we expected". Robert Park has suggested that at this point it should have been clear to Pons and Fleischmann that no fusion was taking place.

At the start of May, the University of Utah asked Congress to provide $25 million to pursue the research, and Dr. Pons was scheduled to meet with representatives of President Bush in early May.

On May 1, the American Physical Society held a session on cold fusion that ran past midnight in which a string of failed experiments were reported. A second session started the next day with other negative reports, and 8 of the 9 leading speakers said that they ruled the Utah claim as dead. Dr. Steven E. Koonin of Caltech called the Utah report a result of "the incompetence and delusion of Pons and Fleischmann". The audience of scientists sat in stunned silence for a moment before bursting into applause. Dr. Douglas R. O. Morrison, a physicist representing CERN, called the entire episode an example of pathological science.

By the end of May, much of the media attention had faded. However, while the research effort also cooled to some degree, projects continued around the world.

In July and November 1989, Nature published papers critical of cold fusion.

In November, a special panel formed by the Energy Research Advisory Board (under a charge of the US Department of Energy) reported the results of its investigation into cold fusion. The scientists on the panel found the evidence for cold fusion to be unconvincing. Nevertheless, the panel was "sympathetic toward modest support for carefully focused and cooperative experiments within the present funding system". Later in 1989 cold fusion was considered by mainstream scientists to be self-deception, experimental error and even fraud. The United States Patent and Trademark Office has rejected most patent applications related to cold fusion since then.

In July 1990, Fleischmann and Pons corrected or removed the errors from their earlier "preliminary note," and published their detailed 58-page paper "Calorimetry of the Palladium-Deuterium-Heavy Water System," in the Journal of Electroanalytical Chemistry. The authors chose to concentrate on calorimetry, as the title suggests, and the paper makes no mention at all of gamma rays.

Also in 1990, Richard Oriani, professor of physical chemistry emeritus of the University of Minnesota published the first replication of the excess heat effect in his paper, "Calorimetric Measurements of Excess Power Output During the Cathodic Charging of Deuterium Into Palladium," in Fusion Technology.

In 1991, Eugene Mallove who was the chief science writer with the MIT News office, said that he believes the negative report issued by MIT's Plasma Fusion Center in 1989, which was highly influential in the controversy, was fraudulent because "data was shifted" without explanation, and as a consequence, this action obscured a possible positive excess heat result at MIT. In protest of MIT's failure to discuss and acknowledge the significance of this data shift, he resigned from his post of chief science writer at the MIT News office on June 7, 1991. He maintained that the data shift was biased to both support the conventional belief in the nonexistence of the cold fusion effect as well as to protect the financial interests of the plasma fusion center's research in hot fusion.

Also in 1991, Nobel Laureate Julian Schwinger said that he had experienced "the pressure for conformity in editor's rejection of submitted papers, based on venomous criticism of anonymous reviewers. The replacement of impartial reviewing by censorship will be the death of science". He resigned as Member and Fellow of the American Physical Society, in protest of its peer review practice on cold fusion.

In 1992, the Wilson group from General Electric challenged the Fleischmann-Pons 1990 paper in the Journal of Electroanalytical Chemistry. The Wilson group asserted that the claims of excess heat had been overstated, but they were unable to "prove that no excess heat" was generated. Wilson concluded that the Fleischmann and Pons cell generated approximately 40% excess heat and amounted to 736 mW, more than ten times larger than the error levels associated with the data.

Despite the apparent confirmation by Wilson, Fleischmann and Pons responded to the Wilson critique and published a rebuttal, also in the same issue of Journal of Electroanalytical Chemistry. According to Steven B. Krivit, Fleischmann and Pons' seminal paper has never been refuted in the scientific literature. According to David Voss, "No experiment has so far convinced the skeptics that cold fusion is real, and most of the big funding sources, which threw money at quick experiments in the early days of cold fusion, have pulled out."

Moving beyond the initial controversy

The 1990s saw little cold fusion research in the United States, much of the research occurring in Europe and Asia. Fleischmann and Pons moved their research laboratory to France, under a grant from the founder of Toyota Motor Corporation. They sued La Repubblica, an Italian Newspaper, and its journalist for their suggestion that cold fusion was a scientific fraud, but lost the libel case in an Italian court. In 1996 they announced in Nature that they would appeal, but they didn't, perhaps because of the reply in Nature.

According to Dr. F.G. Will, Director of The National Cold Fusion Institute, 92 groups of researchers from 10 different countries had reported excess heat, tritium, neutrons or other nuclear effects by 1990. Ed Storms, a radiochemist retired from Los Alamos National Laboratory said that there were 21 published papers reporting excess heat in cold fusion experiments by March 1995. Related articles on experimental research have been published in peer reviewed journals such as Naturwissenschaften, European Physical Journal A, Journal of Solid State Phenomena, Physical Review A, Journal of Electroanalytical Chemistry and Japanese Journal of Applied Physics.

Michael McKubre working on deuterium gas-based cold fusion cell used by SRI International

The generation of excess heat has been reported by (among others):

• Michael McKubre, director of the Energy Research Center at SRI International,
• Giuliano Preparata (ENEA (Italy))
• Richard A. Oriani (University of Minnesota, in December 1990),
• Robert A. Huggins (at Stanford University in March 1990),
• Y. Arata (Osaka University, Japan),
• T. Mizuno (Hokkaido University, Japan),
• T. Ohmori (Japan),

The most common experimental set-ups are the electrolytic (electrolysis) cell and the gas (glow) discharge cell, but many other setups have been used. Electrolysis is popular because it was the original experiment and more commonly known way of conducting the cold fusion experiment; gas discharge is often used because it is believed to provide a better chance of replicating the excess heat results. The experimental results reported by T. Ohmori and T. Mizuno (see Mizuno experiment) have been of particular interest to amateur researchers in recent years.

Researchers share their results at the International Conference on Cold Fusion, recently renamed International Conference on Condensed Matter Nuclear Science. The conference is held every 12 to 18 months in various countries around the world, and is hosted by The International Society for Condensed Matter Nuclear Science, a scientific organization that was founded as a professional society to support research efforts and to communicate experimental results. A few periodicals emerged in the 1990s that covered developments in cold fusion and related new energy sciences. Researchers have contributed hundreds of papers to an international on-line cold fusion library.

A cold fusion calorimeter of the closed type, used at SRI International.

Between 1992 and 1997, Japan's Ministry of International Trade and Industry sponsored a "New Hydrogen Energy Program" of $20 million to research cold fusion. Announcing the end of the program, Dr. Hideo Ikegami stated in 1997, "We couldn't achieve what was first claimed in terms of cold fusion." He added, "We can't find any reason to propose more money for the coming year or for the future."

In 1994, Dr. David Goodstein described the field as follows:

"Cold Fusion is a pariah field, cast out by the scientific establishment. Between Cold Fusion and respectable science there is virtually no communication at all. Cold fusion papers are almost never published in refereed scientific journals, with the result that those works don't receive the normal critical scrutiny that science requires. On the other hand, because the Cold-Fusioners see themselves as a community under siege, there is little internal criticism. Experiments and theories tend to be accepted at face value, for fear of providing even more fuel for external critics, if anyone outside the group was bothering to listen. In these circumstances, crackpots flourish, making matters worse for those who believe that there is serious science going on here."

Cold fusion researchers say that cold fusion is suppressed, and that skeptics suffer from pathological disbelief. They said that there is virtually no possibility for funding in cold fusion in the United States, and no chance of getting published. They said that people in universities refuse to work on it because they would be ridiculed by their colleagues.

In February 2002, a laboratory within the United States Navy released a report that came to the conclusion that the cold fusion phenomenon was in fact real and deserved official funding for research. Navy researchers have published more than 40 papers on cold fusion.

In 2004, the United States Department of Energy decided to take another look at cold fusion to determine if its policies towards cold fusion should be altered due to new experimental evidence. They set up a panel on cold fusion. The nearly unanimous opinion of the reviewers was that funding agencies should entertain individual, well-designed proposals for experiments that address specific scientific issues relevant to the question of whether or not there is anomalous energy production in D/Pd systems, or whether or not D-D fusion reactions occur at energies on the order of a few eV. These proposals should meet accepted scientific standards, and undergo the rigors of peer review. No reviewer recommended a focused federally funded program for low energy nuclear reactions.

In the early 90's, Pamela Mosier-Boss and Stanislaw Szpak, researchers in the U.S. Navy's Space and Naval Warfare Systems Center San Diego, developed an alternative experimental technique called codeposition, involving electroplating cathodes with a particular ratio of palladium and deuterium. In 2006, they reported evidence of what they said was high-energy nuclear reactions concentrated near the probe surface. Based on this work, two other teams have reported similar findings at the American Physical Society meeting of March 2007 (sessions A31 and B31) although interpretations vary.

Set-up of the Fleischmann and Pons experiment

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. The cell was tall and narrow, so that the bubbling action of the gas kept the electrolyte well mixed and of a uniform temperature. 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 rose suddenly to about 50 °C without changes in the input power, for durations of 2 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.

Other kinds of cold fusion

A variety of other methods are known to bring about "cold" 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.

• Fusion with low-energy reactants:
  • Muon-catalyzed fusion 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 −30 to 45 °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. At these energies, two deuterium nuclei can fuse together to form three different products: a helium-3 nucleus and a 2.45 MeV neutron (Q value=3.3 MeV), a helium-3 nucleus and a 3 MeV proton (Q value=4.0MeV), or the less likely products: helium-4+a gamma ray (Q value=23.8 MeV), . 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 much more energy than it produces.
  • 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.

See also

• 2004 DoE panel on cold fusion
• Biological transmutation
• Bubble fusion
• Huemul Project
• Low energy nuclear reaction
• Martin Fleischmann
• Mizuno experiment
• Pathological disbelief
• Pathological science
• CETI Patterson Power Cell
• Stanley Pons
• Timeline of cold fusion
• The Saint (film), a film with a plot surrounding cold fusion

Further information

Reports and reviews

• "Cold Fusion Research" - Energy Research Advisory Board report (November 1989)
  • Conclusions and recommendations section of the report
• U.S. Navy Report Detailing a Decade of Cold Fusion Research "Thermal and Nuclear Aspects of the Pd/D2O System", U.S. Navy TECHNICAL REPORT 1862, February 2002
• 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 has links to the full text of the reviewer's comments, which is not available on the DoE pages, and links to the full text of some of the papers submitted by cold fusion researchers to the review panel. (More links to submitted papers are available here)
  • A response to the review of cold fusion by DOE - by Edmund Storms
  • A discussion of the consequences of the DOE report by Scott R. Chubb
  • Response to the DoE/2004 Review of Cold-Fusion Research - C. Beaudette's critique of the DoE 2004 Cold Fusion Review
• How can cold fusion be real, considering it was disproved by several well-respected Labs in 1989 ? by S. Krivit (2005)
• 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-page 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.
• Review Of Transmutation Reactions In Solids. Miley, G. H. and P. Shrestha in Tenth International Conference on Cold Fusion. 2003. Cambridge, MA.

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

Repositories

• Recent papers on cold fusion listed on New Energy Times
• LENR-CANR Low Energy Nuclear Reactions — Chemically Assisted Nuclear Reactions - information and links on cold fusion research (mainly pro-cold fusion), and an online library of over 500 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

Websites

• International Society for Condensed Matter Nuclear Science - website of the ISCMNS
• L. Kowalski's web site - a collection of commentaries on cold fusion research from a physics teacher
• JL Naudin's web site - the CFR project, a High Temperature Plasma Electrolysis based on the Tadahiko Mizuno work from the Hokkaido University (Japan)
• Aspden, Harold, Cold Fusion Lectures and Essays, 1998 (html available). It gives a firsthand thorough account of the efforts and experiments in the development of cold fusion, including the obstruction and hostility done by state agencies and the industry; it presents also the description of this British engineer and physicist GB Patent no. 2,231,195 (1993) and U.S. Patent no. 5,734,122 (1998).
• A Cold Fusion primer, in English and Italian
• PESWiki Cold Fusion Article - An in-depth look at cold fusion in a Wiki article that can be appended.

Video

• Template:Google video (38 minutes)
• Template:Google video (3 minutes)
• Template:Google video (38 minutes)
• Template:Google video (15 minutes)
• Report 41: Physics and metaphysics of a lost scientific revolution, Angelo Saso, RaiNews24 2006 (18 minutes)

News

1980s

• Elation Should Be Tempered Until Jury Has Examined Experiments The Financial Post (May 1 1989)
• "Physicists Debunk Claim Of a New Kind of Fusion" - The New York Times (May 3 1989)
• "PFC results said to deal blow to fusion claims" - MIT Tech (May 9 1989) - Early cold fusion claims set straight by work in their Plasma Fusion Center

1990s

• Whatever Happened to Cold Fusion? The American Scholar (Late 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 1999)

2000s

• Arthur C Clarke demands cold fusion rethink BBC News (September 2000) See also: [68]
• "Cold Fusion Heats Up. CBC Science, December 2003
• DoE warms to cold fusion Physics Today April 2004.
• Warming up to Cold Fusion Washington Post Magazine (November 2004)
• ICCF-11 Overview With Links to Presentations International Society for Condensed Matter Nuclear Science (November 2004)
• U.S. review rekindles cold fusion debate Nature - (December 2004)
• The 2005 Cold Fusion Colloquium Cold Fusion Times (May 2005) - Public gathering of cold fusion researchers at MIT
• Cold-Fusion Believers Work On, Even as Mainstream Science Gives Them the Cold Shoulder Salt Lake City Weekly (October 2005)
• ICCF-12 Overview With Links to Presentations International Society for Condensed Matter Nuclear Science (December 2005)
• Does fusion scientist 'hold the secret'? Deseret Morning News (March 2006)
• Fleischmann Joins D2Fusion to Develop Cold Fusion Heaters Pure Energy Systems News (March 2006)
  • refutation of this news by New Energy times
• Extraordinary Evidence for Cold Fusion U.S. Navy’s San Diego SPAWAR labs deliver evidence for Cold Fusion (Pamela Mosier-Boss and Stan Szpak) (November 2006)
• Cold Fusion Back on the Menu Robert Park concedes the possibility of low-energy nuclear reactions (March 2007)
• How this 12inch miracle tube could halve heating bills, The Mail, September 2007

Bibliography

• Storms, Edmund. "Science of Low Energy Nuclear Reaction: A Comprehensive Compilation of Evidence and Explanations". World Scientific Publishing Company, 2007 ISBN 9-8127062-0-8.
• Krivit, Steven; Winocur, Nadine. The Rebirth of Cold Fusion: Real Science, Real Hope, Real Energy. Los Angeles, CA, Pacific Oaks Press, 2004 ISBN 0-9760545-8-2.
• Beaudette, Charles. Excess Heat: Why Cold Fusion Research Prevailed, 2nd. Ed. South Bristol, ME, Oak Grove Press, 2002. ISBN 0-9678548-3-0.
• Park, Robert L. Voodoo Science: The Road from Foolishness to Fraud. New York: Oxford University Press, 2000. ISBN 0-19-513515-6. It gives a thorough account of cold fusion and its history which represents the perspective of the mainstream scientific community.
• Mizuno, Tadahiko. Nuclear Transmutation: The Reality of Cold Fusion. Concord, N.H.: Infinite Energy Press, 1998. ISBN 1-892925-00-1.
• Taubes, Gary. Bad Science: The Short Life and Weird Times of Cold Fusion. New York, N.Y. : Random House, 1993. ISBN 0-394-58456-2.
• Huizenga, John R. Cold Fusion: The Scientific Fiasco of the Century. Rochester, N.Y.: University of Rochester Press, 1992. ISBN 1-878822-07-1; ISBN 0-19-855817-1. Huizenga was co-chair of the 1989 DOE panel set up to investigate the Pons/Fleischmann experiment
• Close, Frank E..Too Hot to Handle: The Race for Cold Fusion. Princeton, N.J. : Princeton University Press, 1991. ISBN 0-691-08591-9; ISBN 0-14-015926-6.
• Mallove, Eugene. Fire from Ice: Searching for the Truth Behind the Cold Fusion Furor. Concord, N.H.: Infinite Energy Press, 1991. ISBN 1-892925-02-8. It's an early account from the pro-cold-fusion perspective.
• Kozima, Hideo. The Science of the Cold Fusion phenomenon, Elsevier Science, 2006. ISBN 0-08-045110-1. For physicists, energy researchers and mechanical engineers