Misplaced Pages

Cold fusion: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editNext edit →Content deleted Content addedVisualWikitext
Revision as of 15:27, 19 April 2006 editPcarbonn (talk | contribs)Extended confirmed users4,444 editsm →Pons and Fleischmann's announcement and aftermath: aligning this section to the intro← Previous edit Revision as of 15:41, 19 April 2006 edit undoPcarbonn (talk | contribs)Extended confirmed users4,444 edits →Moving beyond the initial controversy: align with introNext edit →
Line 49: Line 49:


===Moving beyond the initial controversy=== ===Moving beyond the initial controversy===
The 1990s was a quiet period for cold fusion. Having been written off as unworkable by the general public and largely ignored by mainstream scientists who had decided it did not belong in the realm of mainstream science, cold fusion research efforts mainly went underground in the United States, and much of the important work during this time period occurred in Europe and Asia. The government of Japan initiated a "New Hydrogen Energy Program" to research the promise of tapping new hydrogen-based energy sources such as cold fusion (with some limited success). Pons and Fleischmann moved their research laboratory to France, under a grant from the founder of Toyota Motor Corporation. A few periodicals emerged in the 1990s that covered developments in cold fusion and related new energy sciences, and periodic international conferences were conducted to share cold fusion research results. The 1990s was a quiet period for cold fusion. Having been written off as unworkable by the general public and largely ignored by mainstream scientists who had decided it did not belong in the realm of mainstream science, cold fusion research efforts mainly went underground in the United States, and much of the important work during this time period occurred in Europe and Asia. The government of Japan initiated a "New Hydrogen Energy Program" to research the promise of tapping new hydrogen-based energy sources such as cold fusion. Pons and Fleischmann moved their research laboratory to France, under a grant from the founder of Toyota Motor Corporation. A few periodicals emerged in the 1990s that covered developments in cold fusion and related new energy sciences, and periodic international conferences were conducted to share cold fusion research results.


The first decade in the 21st century has seen somewhat of a re-birth for cold fusion, especially in the United States. In February 2002, a laboratory within the that revealed that they had been quietly researching cold fusion for over a decade and had come to the conclusion that the cold fusion phenomenon was in fact real and deserved an official funding source for research. In 2004, the United States Department of Energy (USDOE) decided to take another look at cold fusion to determine if their policies towards cold fusion should be altered due to new experimental evidence. While the ] did not recommend funding a specific program on cold fusion research, just the fact that the USDOE was willing to review cold fusion research that had occurred since 1989 was taken by some as a sign that attitudes towards cold fusion were slowly thawing in the United States. By the middle part of the first decade of the 21st Century, stories about cold fusion research were once again featured in a wide variety of mainstream media outlets (i.e. New York Times, Washington Post, etc.) and even in mainstream science periodicals (i.e. Science, New Scientist, Nature, etc.) that had a quiet policy of ignoring cold fusion developments since the initial controversy in 1989. Even some initial cold fusion commercialization efforts started to take shape as the first decade of the 21st century wore on. In February 2002, a laboratory within the that revealed that they had been quietly researching cold fusion for over a decade and had come to the conclusion that the cold fusion phenomenon was in fact real and deserved an official funding source for research.

In 2004, the United States Department of Energy (USDOE) decided to take another look at cold fusion to determine if their policies towards cold fusion should be altered due to new experimental evidence. They set up a ]. Its 18 reviewers were split approximately evenly on the issue "Is there compelling evidence for power that cannot be attributed to ordinary chemical or solid states sources", a significant change compared to the 1989 DoE panel. However, those who accepted evidence of such power did not believe that a nuclear reaction could explain it: two-thirds of the reviewers did not feel that the evidence was conclusive for low energy nuclear reaction. One found the evidence convincing, and the remainder indicated that 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. The nearly unanimous opinion of the reviewers was that funding agencies should entertain individual, well-designed proposal for experiments in this field.

While researchers continued to report excess heat and some initial cold fusion commercialization efforts started to take shape, science journals such as '']'' and '']'' have continued to write negatively on the subject, for example in March and October 2005 respectively, and many other journals still reject papers on the subject without reviewing them. In January 2006, the '']'', '']'' magazine, '']'', and other major newspapers and magazines wrote negative articles on cold fusion, claiming it was a "scientific misdeed" debunked in 1989 .


==Original Pons and Fleischmann experiment== ==Original Pons and Fleischmann experiment==

Revision as of 15:41, 19 April 2006

The neutrality of this article is disputed. Relevant discussion may be found on the talk page. Please do not remove this message until conditions to do so are met. (Learn how and when to remove this message)
For the article about 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 nuclear fusion reaction that takes place at or near room temperature instead of the millions of degrees required for plasma fusion reactions. It has two major lines of research:

Muon-catalyzed fusion is not controversial but it consumes more energy than it generates. While many scientists accept evidences that LENR reactions are a net source of energy, a majority rejects the possibility that it comes from traditional nuclear fusion reactions. The first low energy nuclear reaction experiment was published in March of 1989, and was front-page news for some time.

Because the detected residues of nuclear fusion are often not commensurate with the energy produced, many critics consider cold fusion as pathological science, and as an idea that would not go away, long after the majority of scientists dismissed it as wrong. Science journals such as Scientific American and Nature have often written negatively on the subject, for example in March and October 2005 respectively, and most other journals reject papers on the subject without reviewing them. In January 2006, the Washington Post, Time magazine, The Guardian, and other major newspapers and magazines wrote negative articles on cold fusion, claiming it was a "scientific misdeed" debunked in 1989 .

Yet, researchers continue to report generation of excess heat using electrolytic cells, gas loading, and ion implantation . Over 3,000 cold fusion papers have been published including about 1,000 in mainstream, peer-reviewed journals . Several peer-reviewed papers continue to be published every year . In 2004, the US Department of Energy set up a panel to review 15 years of research in cold fusion. About half of the reviewing scientists indicated they were somewhat convinced that power is actually generated in these experiments, and that this power cannot be attributed to ordinary chemical or solid state sources. Yet, two thirds of the scientists in the panel did not feel that the evidence was conclusive for low energy nuclear reactions. They favored continued research, although not in a large federally funded program.

A cheap and simple process to generate energy could have substantial economic impact. If low energy nuclear reaction can generate energy economically, it would help reduce our dependence on oil, our production of greenhouse gas, and the risk of global warming. If low energy cold fusion exists and can be made practical, it would have advantages over plasma fusion, because it apparently produces little nuclear radiation and it can be scaled to small devices, whereas plasma fusion tokamak reactors can only be made on larger scales, and produce substantial amounts of radiation.

The term "cold nuclear fusion" was first used in the scientific literature by Johann Rafelski and Steven E. Jones of Brigham Young University in 1986.

History of cold fusion by electrolysis

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. In the late nineteen-twenties, 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 acknowledged that the helium they measured was due to background from the air.

In 1927, 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.

Pons and Fleischmann's announcement and aftermath

On March 23, 1989, the chemists Stanley Pons and Martin Fleischmann ("P and F") at the University of Utah spoke at a press conference held by the University of Utah and reported the production of excess heat that they say could only be explained by a nuclear process. The report was particularly astounding given the simplicity of the equipment: essentially an electrolysis cell containing heavy water (deuterium oxide) and a palladium cathode which rapidly absorbed the deuterium produced during electrolysis. 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. In 1988 they 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 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 had since 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, but had since moved to electrolytic cells similar to those being worked on by Pons and Fleischmann, which he referred to as piezonuclear fusion. 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, and 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, 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 Federal Express. However Pons and Fleischmann broke that apparent agreement and 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. Thus the teams both rushed to publish, which has perhaps muddied the field more than 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 additional competing claims, counterclaims, and suggested explanations kept the topic on the front pages, and led to what writers have referred to as "fusion confusion."

In mid-May Pons received a huge standing ovation during a presentation at the American Chemical Society. The same month 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 1 a meeting of the American Physical Society held a session 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. The field appeared split between the "chemists" and the "physicists".

At the end of May the Energy Research Advisory Board (under a charge of the US Department of Energy) formed a special panel to investigate cold fusion. The scientists in 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".

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 their own. Pons and Fleischmann later apparently said that there was a "secret" to the experiment, a statement that infuriated the majority of scientists to the point of dismissing the experiment out of hand.

By the end of May much of the media attention had faded. This was due not only to the competing results and counterclaims, but also to the limited attention span of modern media. 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 , which cast the idea of cold fusion out of the mainstream of acceptable science. As 1989 wore on, cold fusion was written off by mainstream scientists as self-deception, experimental error and even fraud, and was held out for years as a prime example of pseudoscience.

Moving beyond the initial controversy

The 1990s was a quiet period for cold fusion. Having been written off as unworkable by the general public and largely ignored by mainstream scientists who had decided it did not belong in the realm of mainstream science, cold fusion research efforts mainly went underground in the United States, and much of the important work during this time period occurred in Europe and Asia. The government of Japan initiated a "New Hydrogen Energy Program" to research the promise of tapping new hydrogen-based energy sources such as cold fusion. Pons and Fleischmann moved their research laboratory to France, under a grant from the founder of Toyota Motor Corporation. A few periodicals emerged in the 1990s that covered developments in cold fusion and related new energy sciences, and periodic international conferences were conducted to share cold fusion research results.

In February 2002, a laboratory within the United States Navy released a report that revealed that they had been quietly researching cold fusion for over a decade and had come to the conclusion that the cold fusion phenomenon was in fact real and deserved an official funding source for research.

In 2004, the United States Department of Energy (USDOE) decided to take another look at cold fusion to determine if their policies towards cold fusion should be altered due to new experimental evidence. They set up a panel on cold fusion. Its 18 reviewers were split approximately evenly on the issue "Is there compelling evidence for power that cannot be attributed to ordinary chemical or solid states sources", a significant change compared to the 1989 DoE panel. However, those who accepted evidence of such power did not believe that a nuclear reaction could explain it: two-thirds of the reviewers did not feel that the evidence was conclusive for low energy nuclear reaction. One found the evidence convincing, and the remainder indicated that 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. The nearly unanimous opinion of the reviewers was that funding agencies should entertain individual, well-designed proposal for experiments in this field.

While researchers continued to report excess heat and some initial cold fusion commercialization efforts started to take shape, science journals such as Scientific American and Nature have continued to write negatively on the subject, for example in March and October 2005 respectively, and many other journals still reject papers on the subject without reviewing them. In January 2006, the Washington Post, Time magazine, The Guardian, and other major newspapers and magazines wrote negative articles on cold fusion, claiming it was a "scientific misdeed" debunked in 1989 .

Original Pons and Fleischmann experiment

A cold fusion calorimeter of the open type, used at the New Hydrogen Energy Institute in Japan. Source: SPAWAR/US Navy TR1862

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.

Arguments in the controversy

Current understanding of nuclear processes

Current understanding of hot nuclear fusion has shown:

  • In order for fusion to occur, the electrostatic force (Coulomb repulsion) between the positively charged nuclei must be overcome. Once the distance between the nuclei becomes comparable to one femtometre, the attractive strong interaction takes over and the fusion may occur. However, the repulsive Coulomb interaction between the nuclei separated by several femtometres is greater than interactions between nuclei and electrons by approximately six orders of magnitude. Overcoming that requires an energy on the order of 10 MeV per nucleus, whereas the energies of chemical reactions are on the order of several electron-volts; it is hard to explain where the required energy would come from in room-temperature matter. The electrostatic environment interior to a palladium metal matrix is very different from that of a plasma, and so the possibility exists that deuterons embedded in palladium settle at points and in channels within the metal's electron orbitals which substantially increase the likelihood of deuteron collisions.
  • If the excess heat were generated by the hot fusion of two deuterium atoms, the most probable outcome would be the generation of either a tritium atom and a proton, or a He and a neutron. The level of neutrons, tritium and He actually observed in Fleischmann-Pons experiment have been well below the level expected in view of the heat generated, implying that hot fusion reactions cannot explain it. However, deuterons in a metal matrix have substantially less angular momentum (which is proportional to temperature and limited by interactions with the enclosing solid) than those in a plasma. This difference may explain the observed difference in branching ratios.
  • Fusion of deuterium into helium-4: if the excess heat were generated by the hot fusion of two deuterium atoms into He, a reaction which is normally extremely rare, gamma rays and helium would be generated. Insufficient levels of gamma rays relative to hot fusion have been observed in proportion to the heat generated. U.S. Navy researchers Stanislaw Szpak and Pamela Boss, with Jerry J. Smith from the Dept. of Energy have measured bremsstrahlung radiation consistent with very high energy alpha particles, suggesting that energy may be released as He nuclei momentum instead of the gamma radiation observed in plasma fusion.

Reproducibility of the result

While some scientists have reported to have reproduced the excess heat with similar or different set-ups, they could not do so with predictable results, and many others failed. Some see this as a proof that the cold fusion is pseudoscience, or more precisely, pathological science.

Yet, it is not uncommon for a new phenomenon to be difficult to control and replicate, 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 experimentalists, can in some cases be the preliminary steps leading to recognized discoveries.

The reproducibility of the Cold Fusion result will remain the main issue regarding the Cold Fusion controversy until a scientist designs an experiment that is fully Reproducible On Demand (ROD), by simply following a set of instructions or recipe, or when excess power generation is possible to produce continuously rather than sporadically, and can be easily proven to the broader scientific community. Reproducing excess heat and nuclear ashes in a Cold Fusion experiment on demand appears to be hampered by the tremendous amount of variables, some of which are unknown or poorly understood as of 2006, involved in actually reproducing the Cold Fusion reaction reliably in a cell. Further research efforts will be necessary to determine which variables in a Cold Fusion cell require control and modification to achieve consistent Reproducible On Demand (ROD) or 100% reproducibility.

Energy source versus power store

It has been suggested that the observed excess power output which begins after a cell is operated for a long time may be due to energy accumulated in the cell during operation. This would require a systematic error in calorimetry (in other words that the cell is drawing more power than goes out, but calorimetry incorrectly shows the two to be equal). Additionally, the amount of energy reported in some of the experiments appears to be too great compared to the small mass of material in the cell, for it to be stored by any known chemical process. Dennis Cravens, a professor of chemistry and physics at Eastern New Mexico University, is working on a completely self-contained cold fusion device based on a Stirling engine. While this is in the early stages, if successful and capable of doing work on the external environment it would confirm production of excess energy without the need for measurements.

Theory and pathway problems

Cold fusion's most significant theoretical problem in the eyes of mainstream science, especially nuclear physicists, is that no nuclear theories or nuclear pathways currently exist that properly explain how a cold fusion reaction can cause nuclear fusion to occur at relatively low temperatures (much lower than is generally believed possible). The well established and tested nuclear pathways that allow hot fusion reactions to occur at very high temperatures, which result in well known fusion nuclear signatures such as gamma rays and neutrons, just do not work for cold fusion, as is evidenced by the lack of typical fusion nuclear signatures. In addition to the reproducibility issue, which is really an experimental, not a theoretical problem, the lack of a viable theoretical nuclear pathway is why many mainstream scientists have such a hard time believing cold fusion claims have a nuclear origin. A wide variety of competing theories have been put forward to explain cold fusion and the nuclear pathways that allow the cold fusion reaction to occur. A firmer understanding of the underlying theories and pathways will only be possible with further cold fusion research and data.

Continuing research efforts

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

There are still a number of researchers, both professional and amateur, that are conducting research world-wide into the possibilities of generating power with cold fusion. Scientists in several countries continue the research, and meet at the International Conference on Cold Fusion (recently renamed International Conference on Condensed Matter Nuclear Science) to share their results. 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 cold fusion research efforts and to communicate cold fusion experimental results.

The generation of excess heat has been reported by

among others.

The excess heat experimental results reported by T. Ohmori and T. Mizuno (see Mizuno experiment) have come under particular interest by amateur cold fusion researchers in recent years. A number of amateur cold fusion scientists, some of whom have distinguished scientific careers and research cold fusion as an aside, have used the cold fusion protocol outlined by Mizuno to generate excess heat Coefficients of Productivity (COP) in excess of 1.5 in home-made cold fusion cells. Including this succesful replication reported in March 2006, which took place in Colorado, United States and replications reported in France by JL Naudin and researchers connected to his laboratory JNL Labs.

In the best experimental set-ups, excess heat has been observed in about half of attempts. To gain broader acceptance from the mainstream scientific community, cold fusion researchers acknowledge that they must achieve Reproducibility On Demand (ROD) or high reproducibility, meaning any researcher with the proper equipment can replicate the cold fusion experiment and observe excess heat. In addition to extensive reports of excess heat from cold fusion experimentors, fusion byproducts such as helium-4 or tritium and transmutations of elements (changing an element into another element) have been observed by some cold fusion researchers.

Dr. Michael McKubre thinks a working cold fusion reactor is possible. Dr. Edmund Storms, Los Alamos National Laboratory (ret.) maintains an international database of research into cold fusion.

Excess heat production is an important characteristic of the effect that has created the most criticism. This is understandable because calorimetry is a difficult measurement that is susceptible to systematic errors. In addition, the original measurements, as well as a few of the attempted reproduction studies, have been criticized for various errors. Nevertheless, evidence is available that is based on well-designed and well-understood precision calorimetry methods, for example Seebeck and flow calorimeters. For example, McKubre et al. Template:Ref harvard at SRI developed a state-of-the-art flow calorimeter that was used to study many samples that showed production of significant anomalous energy. Over 30 similar studies Template:Ref harvard have observed the same general behavior as was reported by these workers. Of course, all of the positive results could be caused by various errors. This possibility has been explored in many papers, which have been reviewed and summarized by Storms Template:Ref harvard . Although a few of the suggested errors might have affected a few studies, no error has been identified that can explain all of the positive results, especially those using well designed methods. At this time, researchers in the field feel confident that anomalous energy is produced regardless of its source. This conclusion is important regardless of whether nuclear reactions are the source or not.

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 a nuclear product. Until the work of Miles et al. Template:Ref harvard, various unexpected nuclear products had been detected but never in sufficient amounts. Miles et al. showed that helium was generated when anomalous heat was measured and that the relationship between the two measurements was consistent with the amount of energy known to result from a d-d fusion reaction. Since then five other studies Template:Ref harvard have observed the same relationship. Of course, some of the detected helium could have resulted from helium known to be in normal air. Also, the heat measurements could be wrong in just the right amount every time the measurements were made. Even though these possibilities could have been used to explain one study, it is unlikely that such an advantageous combination of error can explain all of the results, especially when active efforts were made to reduce these errors. At the present time, researchers in the field believe that heat and helium are related, but the source of the helium is still to be determined. In other words, the helium may not result from d-d fusion.

File:ColdFusionAutoradiograph.jpg
An autoradiograph showing the effects of tritium from a cold fusion experiment at the Neutron Physics Division, Bhabha Atomic Research Centre, Bombay, India

Besides helium, other nuclear products are detected in much smaller quantities. Early in the history, great effort was made to detect neutrons, an expected nuclear product from the d-d fusion reaction. Except for occasional bursts, the emission rate was found to be near the limit of detection or completely absent. This fact was used to reject the initial claim. It is now believed that the few neutrons are caused by a secondary nuclear reaction, possibily having nothing to do with the helium producing reaction. Tritium is another expected product of d-d fusion, which was sought. Too little tritium was detected so that once again the original claims were inconsistent with expectations. Nevertheless, the amount of tritium detected could not be explained by any conventional process after all of the possibilities had been completely explored. The source of tritium is still unknown although it appears to result from a nuclear reaction that is initiated within the apparatus. Various nuclear products normally associated with d-d fusion also have been detected as energetic emissions, but at very low rates.

Finally, the presence of heavy elements having unnatural isotopic ratios and in unexpected large amounts are detected under some conditions. These are the so called transmutation products. Work in Japan Template:Ref harvard Template:Ref harvard Template:Ref harvard Template:Ref harvard Template:Ref harvard has opened an entirely new aspect to the phenomenon by showing that impurity elements in palladium, through which D2 is caused to pass, are converted to heavier elements to which 2D, 4D or 6D (deuterons) have been added. The claims have been replicated in Japan and similar efforts are underway at the U.S. Naval Research Laboratory (NRL).

In 2004, the United States Department of Energy (DoE), upon reviewing the observations and best evidence reported by cold fusion researchers, came to mixed conclusions about the reality of the claims and did not recommend a federally funded research program. Template:Ref harvard Template:Ref harvard (see DoE panels on cold fusion) In keeping with this opinion, some journals do not accept submissions related to cold fusion, and Scientific American has often attacked the subject. In contrast, other prestigious journals, such as the Japanese Journal of Applied Physics, continue to publish studies on the subject.

Experimental methods of producing cold fusion

The signatures of cold fusion, excess heat and helium-4/tritium, have been reported by experimenters in numerous countries using a variety of different experimental cold fusion set-ups, including:

  • Electrolytic Cells (using liquids and solids) / the classic Pons and Fleischmann cell
  • Gas (Glow) Discharge Cells / Ohmori-Mizuno type set-up
  • Gas Reactions
  • Ion bombardment
  • Cavitations Reactions
  • Solids With Pressurized Gas
  • Plasma Discharge
  • Phase Change or Chemical Reactions
  • Biological Systems

Source: (Storms 2001)

The most common experimental set-ups are the electrolytic (electrolysis) cell and the gas (glow) discharge cell. The former because it was the original experiment and more commonly known way of producing cold fusion, and the latter because it has proven to be the set-up that provides an experimenter a better chance at replication of the cold fusion results than the other methods.

Accounting for experimental error

In the early 1990s when the field began, hundreds of cold fusion replications were published in mainstream peer reviewed journals. These papers were subjected to especially intense and rigorous peer-review scrutiny, because the claims are so controversial. Some of the papers took months or years to pass review. The reviewers did not find any experimental errors (or the papers would not have passed), and skeptics who challenge this work have never published any papers showing experimental errors in them.

Cold fusion researchers have often gone to great lengths to eliminate the potential for error in their experiments or to account for the possibility of error when performing data reduction after the experiments. A field such as cold fusion is particularly susceptible to charges of error because some people believe the results are theoretically impossible. Others claim that the results may be in error because the levels of excess heat reported are often small, 50 to 200 milliwatts (one thousandth of a watt) and by their nature are somewhat difficult to accurately measure. Other results are much larger, from 1 to 5 watts. The science of measuring heat, calorimetry, is tedious and involved, especially when the heat measurements are in the milliwatt range. Calorimeters and microcalorimeters capable of measuring milliwatts and even picowatts were developed decades ago, and these proven designs have been employed in cold fusion, but they require skill and attention to operate, and a skeptic who knows little about them may wonder whether they are being used correctly.

Some cold fusion researchers have spent great efforts perfecting their calorimetry equipment and techniques, but even after such efforts their results come under question. There have also been questions raised about the calibration of calorimeters before and during cold fusion experiments (Shanahan 2002), which were addressed in a paper published in Thermochim. Acta (Storms 2006).

The solution to addressing charges of experimental error skewing cold fusion results is to either obtain positive cold fusion results that can be measured in ranges that are so large that they are well outside the range of experimental error, or to devise calorimeters and calorimetry procedures that are so accurate that they can be trusted to measure heat in the milliwatt range. Cold fusion researchers have concentrated on the latter approach. Multiple calorimeter types, such as static, flow and Seebeck have been used to obtain similar excess heat results. This should alleviate criticisms of systematic experimental error creeping into the positive results -- because the systems are physically different -- but unfortunately the criticisms are repeated.

Related technologies that might advance cold fusion

There are important technological developments occurring in other fields of research, such as material sciences, that could have a profound impact on the development of cold fusion in coming years. Specifically, nanotechnology (building materials and machines at the atomic level) is an emerging technology that will likely impact cold fusion research and development in the future. Since the cold fusion reaction appears to require very specific metal structures and ratios to be present in the cathod in order to produce the reaction reliably, nanotechnology will likely play a large role in understanding and perfecting the cold fusion effect. Nanotechnology will allow for custom made metal cathodes used in cold fusion cells that are built to perfection on the atomic level in ratios and structures that optimize the cold fusion reaction. Such use of nanotechnology could increase the reliability and power output of the cold fusion reaction to produce energy on demand in a reliable and controlled manner, perhaps paving the way for the commercial development of controllable cold fusion products.

Commercial developments

Cold fusion's commercial viability is unknown. Thorough understanding of the cold fusion effect is necessary for commercialization and has not yet been achieved (although several competing theories exist). Some researchers have indicated that the effect can occur in metals other than expensive palladium, such as titanium and nickel. Studies showing the largest power densities make use of palladium, and even those results are not even close to energy levels that are commercially substantial, in fact they are orders-of-magnitude too small to be commercially viable. Researchers have not yet discovered methods to prevent cathodes from deteriorating, cracking, and melting during the cold fusion reaction (occasionally, cells have been known to burst). Essentially, the cold fusion reaction can not be thoroughly controlled and has not been proven to be scalable to larger sizes, both of which are qualities that are necessary for commercialization of an energy technology. Additionally, the most widely reproduced cold fusion experiments produce power in bursts, not continiously as is needed for many commercial applications.

There are various companies which publicly claim to be developing cold fusion devices. There are also some private cold fusion commercialization efforts that are rumored to be ongoing.

Companies publicly claiming to be developing cold fusion devices, include: Energetics Technologies Ltd. (Israel) <no known website>, D2Fusion, and JET Thermal Products. Ongoing developments concerning cold fusion commercialization efforts are tracked at peswiki.

Other kinds of fusion

A variety of other methods are known to affect nuclear fusion. Some are "cold" in the strict sense that 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.

Locally cold fusion :

  • 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. Net energy production from this reaction is not believed to be possible because of the energy required to create muons, their 2.2 µs half-life, and the chance that a muon will bind to the new alpha particle and thus stop catalyzing fusion.

Generally cold, locally hot fusion :

  • 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 (aka sono fusion). 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.
  • 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.
  • 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.
  • Pyroelectric fusion was reported in April 2005 by a team at UCLA. The scientists used a pyroelectric crystal heated from −34 to 7°C (−30 to 45°F), 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 10 K) as an estimate in their modeling. At these energy levels, two deuterium nuclei can fuse together to produce a helium-3 nucleus, a 2.45 MeV neutron and bremsstrahlung. Although it makes a useful neutron generator, the apparatus is not intended for power generation since it requires far more energy than it produces.

Hot fusion :

The methods in the second group are examples of non-equilibrium systems, in which very high temperatures and pressures are produced in a relatively small region adjacent to material of much lower temperature. In his doctoral thesis for MIT, Todd Rider did a theoretical study of all non-equilibrium fusion systems. He demonstrated that all such systems will leak energy at a rapid rate due to bremsstrahlung, radiation produced when electrons in the plasma hit other electrons or ions at a cooler temperature and suddenly decelerate. The problem is not as pronounced in a hot plasma because the range of temperatures, and thus the magnitude of the deceleration, is much lower.

See also

Fusion power, processes and devices
Core topics
Nuclear fusion
Processes,
methods
Confinement
type
Gravitational
  • Alpha process
  • Triple-alpha process
  • CNO cycle
  • Fusor
  • Helium flash
  • Nova
  • Proton–proton chain
  • Carbon-burning
  • Lithium burning
  • Neon-burning
  • Oxygen-burning
  • Silicon-burning
  • R-process
  • S-process
    • Magnetic
    Magneto-inertial
    Inertial
    Electrostatic
    Other forms
    Devices,
    experiments
    Magnetic
    confinement
    Tokamak
    International
    Americas
    Asia,
    Oceania
    Europe
    Stellarator
    Americas
    Asia,
    Oceania
    Europe
    Pinch
    RFP
    Mirror
    Other
    Magneto-inertial
    Inertial
    confinement
    Laser
    Americas
    Asia
    Europe
    Non-laser

    References

    Books

    • Krivit, Steven ; Winocur, Nadine. The Rebirth of Cold Fusion: Real Science, Real Hope, Real Energy. Los Angeles, CA, Pacific Oaks Press, 2004 ISBN 0976054582.
    • Beaudette, Charles. Excess Heat: Why Cold Fusion Research Prevailed, 2nd. Ed. South Bristol, ME, Oak Grove Press, 2002. ISBN 0967854830.
    • Park, Robert L. Voodoo Science: The Road from Foolishness to Fraud. New York: Oxford University Press, 2000. ISBN 0195135156.
    • Mizuno, Tadahiko. Nuclear Transmutation: The Reality of Cold Fusion. Concord, N.H.: Infinite Energy Press, 1998. ISBN 1892925001.
    • Taubes, Gary. Bad Science: The Short Life and Weird Times of Cold Fusion. New York, N.Y. : Random House, 1993. ISBN 0394584562.
    • Huizenga, John R. Cold Fusion: The Scientific Fiasco of the Century. Rochester, N.Y.: University of Rochester Press, 1992. ISBN 1878822071; ISBN 0198558171.
    • Close, Frank E..Too Hot to Handle: The Race for Cold Fusion. Princeton, N.J. : Princeton University Press, 1991. ISBN 0691085919; ISBN 0140159266.
    • Mallove, Eugene. Fire from Ice: Searching for the Truth Behind the Cold Fusion Furor. Concord, N.H.: Infinite Energy Press, 1991. ISBN 1892925028.

    Reports and reviews

    Papers

    Journals and publications

    Websites and repositories

    News

    1980s

    1990s

    2000s

    Categories: