Cold fusion

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

Arguments in the controversy

Here are the main arguments in the controversy:

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Experimental design

One of the main criticisms of the cold fusion claims is that the experimental design made it very difficult to get reliable and repeatable results. In particular, there are many different ways by which the experiment can exchange energy with its environment, and the book-keeping necessary to establish whether or not there is any net energy gain has been criticized for being difficult to do correctly and prone to error.

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This objection could be overruled either by creating an experiment which is less subject to errors, or by looking for signs of fusion which have nothing to do with excess heat. Neither of these strategies has produced conclusive evidence that this cold fusion process exists.

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Reproducibility of excess heat

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

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However, it is not uncommon for a new phenomenon to be difficult to control, and to bring erratic results. For example, attempts to repeat electrostatic experiments (similar to those performed by Benjamin Franklin) often fail due to excessive air humidity. That does not mean that electrostatic phenomena are fictitious, or that experimental data are fraudulent. On the contrary, occasional observations of new events, by qualified experimenters, can in some cases be the essential steps leading to recognized discoveries. At the same time, it is also the case that experiments are hard to do, and it is easy to come up with results which look anomalous but which are in fact the result of experimental design deficiencies.

Related Topics:
Benjamin Franklin - Humidity

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The reproducibility of the result will remain the main issue in cold fusion research until an experiment is designed which is fully reproducible by following a clear recipe, and which preferably generates power continuously rather than sporadically and does so in a way that cannot be attributed to experimental defects. As of 2004 this issue may have been resolved by the work of Mike McKubre at SRI International.

Related Topics:
Recipe - Generates power - 2004 - SRI International

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Lack of expected decay products

Even in the face of inconsistent evidence regarding the production of heat, cold fusion

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could be established by observation of decay products which are specific only to fusion. According to conventional fusion theory, if the excess heat were generated by the fusion of 2 deuterium atoms, the most probable outcome would be the generation of either a tritium atom and a proton, or a 3He and a neutron. The level of neutrons, tritium and 3He reported from the Fleischmann-Pons experiment was well below the level expected in view of the heat reported—such a neutron flux would in fact have been lethal—implying that these fusion reactions cannot explain it. Researchers in the cold fusion field claim that 4He is the dominant by-product of cold fusion. In conventional fusion, less than 1% of the nuclear products are seen as 4He.http://newenergytimes.com/Library/2003MilesM-ICCF-10-Correlation-Of-Excess.pdf

Related Topics:
Deuterium - Tritium - Neutron

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http://newenergytimes.com/Library/1991BushB-HeliumProductionDuringTheElectrolysis.pdfhttp://newenergytimes.com/Library/2002DeNinnoA-ExperimentalEvidenceOf4HeProduction.pdfhttp://www.newenergytimes.com/library/1998GozziD-HeGozziDxrayheatex.pdf

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A larger collection of related papers on helium evolution is here.

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

Related Topics:
Farnsworth-Hirsch Fusor - Neutron

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This experimental result could be and has been explained by arguing that the current understanding of physics is incorrect, but this leads to other problems.

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Current understanding of physics

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

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• Nuclear reaction in general: The average density of deuterium in the palladium rod seems vastly insufficient to force pairs of nuclei close enough for fusion to occur according to mechanisms known to mainstream theories. The average distance is approximately 0.17 nanometers, a distance at which the attractive strong nuclear force cannot overcome the Coulomb repulsion. Actually, deuterium atoms are closer together in D₂ gas molecules, which do not exhibit fusion.
• Fusion of deuterium into helium 4: if the excess heat were generated by the fusion of two deuterium atoms into ⁴He, a reaction which is normally extremely rare, gamma rays and helium would be generated. Again, insufficient levels of helium and gamma rays have been observed to explain the excess heat, and there is no known mechanism to explain how gamma rays could be converted into heat.

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

Related Topics:
Superconductivity - Brownian motion - High-temperature superconductivity - Polywater - N-rays

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

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

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

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

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

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Energy source vs power store

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

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Cold fusion researchers disagree. They point out that in all experiments in which excess heat has been recorded, the overall balance has been positive; there are no instances in which a heat deficit was recorded first, that would balance out the excess. In most bulk palladium electrochemical experiments, an incubation period of 10 to 20 days is followed by continuous excess heat production, which often continues longer than the incubation period. "Isothermal Flow Calorimetric Investigations of the D/Pd System" shows typical examples. {{ref|McKubre0}} Since the excess heat is easily detected, at a high signal to noise ratio, and the initial deficit would have to be even larger than the excess that follows, it would easily be detected. Researchers also point out that most cells produce far more energy than any known chemical storage mechanism would permit. Chemical processes store (or produce) at most 12 eV per atom of reactant, whereas many cold fusion experiments have produced hundreds of eV per atom of cathode material, and some have produced ~100,000 eV per atom.

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Furthermore, many researchers, notably Kainthla et al. {{ref|Kainthla}} and McKubre et al. {{ref|McKubre1}} have conducted careful inventories of chemical fuel and potential storage mechanisms in cold fusion cells, and they have found neither fuel nor spent ash that could account for more than a tiny fraction of the excess heat. Since many cells have released large amounts of energy, a megajoule or more, this chemical fuel would have to be present in macroscopic amounts. In fact, in many cases the volume of ash would greatly exceed the entire cell volume. These issues of energy storage and chemical fuel hypotheses have been discussed in the literature exhaustively. See, for example, "A Response to the Review of Cold Fusion by the DoE", section II.1.2.{{ref|Storms}}

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