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Cold fusion is a hypothesized type of nuclear reaction that would occur at, or near, room temperature. It would contrast starkly with the "hot" fusion that is known to take place naturally within stars and artificially in hydrogen bombs and prototype fusion reactors under immense pressure and at temperatures of millions of degrees, and be distinguished from muon-catalyzed fusion. There is currently no accepted theoretical model that would allow cold fusion to occur.
Deuterium (or hydrogen-2, symbol 2
H
or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other being protium, or hydrogen-1). The nucleus of a deuterium atom, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutrons in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom of deuterium among every 6,420 atoms of hydrogen (see heavy water). Thus deuterium accounts for approximately 0.0156% by number (0.0312% by mass) of all the naturally occurring hydrogen in the oceans (i.e 4.85 1013 tonnes of deuterium – mainly in form of HOD and only rarely in form of D2O – in 1.4 1018 tonnes of water), while protium accounts for more than 99.98%. The abundance of deuterium changes slightly from one kind of natural water to another (see Vienna Standard Mean Ocean Water). (Tritium is yet another hydrogen isotope with symbol 3
H
or T. It has two neutrons, and is radioactive and much rarer than deuterium.)
Heavy water is a form of water whose hydrogen atoms are all deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The presence of the heavier hydrogen isotope gives the water different nuclear properties, and the increase in mass gives it slightly different physical and chemical properties when compared to normal water.
The neutron is a subatomic particle, symbol
n
or
n0
, which has a neutral charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one dalton, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks.
Nuclear fusion is a reaction in which two or more atomic nuclei, usually deuterium and tritium, combine to form one or more different atomic nuclei and subatomic particles. The difference in mass between the reactants and products is manifested as either the release or absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the atomic nuclei before and after the reaction. Nuclear fusion is the process that powers active or main-sequence stars and other high-magnitude stars, where large amounts of energy are released.
Tritium or hydrogen-3 is a rare and radioactive isotope of hydrogen with a half-life of ~12.3 years. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (protium) contains one proton and zero neutrons, and that of hydrogen-2 (deuterium) contains one proton and one neutron.
Bubble fusion is the non-technical name for a nuclear fusion reaction hypothesized to occur inside extraordinarily large collapsing gas bubbles created in a liquid during acoustic cavitation. The more technical name is sonofusion.
Fusion power is a proposed form of power generation that would generate electricity by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices designed to harness this energy are known as fusion reactors. Research into fusion reactors began in the 1940s, but as of 2023, no device has reached net power.
A neutron source is any device that emits neutrons, irrespective of the mechanism used to produce the neutrons. Neutron sources are used in physics, engineering, medicine, nuclear weapons, petroleum exploration, biology, chemistry, and nuclear power.
Palladium hydride is metallic palladium that contains a substantial quantity of hydrogen within its crystal lattice. Despite its name, it is not an ionic hydride but rather an alloy of palladium with metallic hydrogen that can be written PdHx. At room temperature, palladium hydrides may contain two crystalline phases, α and β. Pure α-phase exists at x < 0.017 whereas pure β-phase is realised for x > 0.58; intermediate x values correspond to α-β mixtures.
Muon-catalyzed fusion is a process allowing nuclear fusion to take place at temperatures significantly lower than the temperatures required for thermonuclear fusion, even at room temperature or lower. It is one of the few known ways of catalyzing nuclear fusion reactions.
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released due to fission, allowing for more neutron-induced fission reactions to take place. The rate of fission is thereby greatly increased such that much more of the fissile material is able to undergo fission before the core explosively disassembles. The fusion process itself adds only a small amount of energy to the process, perhaps 1%.
Aneutronic fusion is any form of fusion power in which very little of the energy released is carried by neutrons. While the lowest-threshold nuclear fusion reactions release up to 80% of their energy in the form of neutrons, aneutronic reactions release energy in the form of charged particles, typically protons or alpha particles. Successful aneutronic fusion would greatly reduce problems associated with neutron radiation such as damaging ionizing radiation, neutron activation, reactor maintenance, and requirements for biological shielding, remote handling and safety.
Pyroelectric fusion refers to the technique of using pyroelectric crystals to generate high strength electrostatic fields to accelerate deuterium ions (tritium might also be used someday) into a metal hydride target also containing deuterium (or tritium) with sufficient kinetic energy to cause these ions to undergo nuclear fusion. It was reported in April 2005 by a team at UCLA. The scientists used a pyroelectric crystal heated from −34 to 7 °C (−29 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 109 K) as an estimate in their modeling. At these energy levels, two deuterium nuclei can fuse 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.
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission.
The International Fusion Materials Irradiation Facility, also known as IFMIF, is a projected material testing facility in which candidate materials for the use in an energy producing fusion reactor can be fully qualified. IFMIF will be an accelerator-driven neutron source producing a high intensity fast neutron flux with a spectrum similar to that expected at the first wall of a fusion reactor using a deuterium-lithium nuclear reaction. The IFMIF project was started in 1994 as an international scientific research program, carried out by Japan, the European Union, the United States, and Russia, and managed by the International Energy Agency. Since 2007, it has been pursued by Japan and the European Union under the Broader Approach Agreement in the field of fusion energy research, through the IFMIF/EVEDA project, which conducts engineering validation and engineering design activities for IFMIF. The construction of IFMIF is recommended in the European Roadmap for Research Infrastructures Report, which was published by the European Strategy Forum on Research Infrastructures (ESFRI).
Martin Fleischmann FRS was a British chemist who worked in electrochemistry. Premature announcement of his cold fusion research with Stanley Pons, regarding excess heat in heavy water, caused a media sensation and elicited skepticism and criticism from many in the scientific community.
Lattice confinement fusion (LCF) is a type of nuclear fusion in which deuteron-saturated metals are exposed to gamma radiation or ion beams, such as in an IEC fusor, avoiding the confined high-temperature gasses used in other methods of fusion.
Pycnonuclear fusion is a type of nuclear fusion reaction which occurs due to zero-point oscillations of nuclei around their equilibrium point bound in their crystal lattice. In quantum physics, the phenomenon can be interpreted as overlap of the wave functions of neighboring ions, and is proportional to the overlapping amplitude. Under the conditions of above-threshold ionization, the reactions of neutronization and pycnonuclear fusion can lead to the creation of absolutely stable environments in superdense substances.
Andrea Lynn "Annie" Kritcher is an American nuclear engineer and physicist who works at the Lawrence Livermore National Laboratory. She was responsible for the development of Hybrid-E, a capsule that enables inertial confinement fusion. She was elected Fellow of the American Physical Society in 2022.
References
- ↑ "Remembering the life of Maryann Mosier 1938 - 2011". obituaries.starbeacon.com. Retrieved 2022-10-29.
- ↑ "Lattice Confinement Fusion and Fusion-Fast-Fission Energy Source Development" (PDF).
- ↑ Morbier-Boss, Pamela A. (1986). "Physiochemical studies of crown-solvent complexations".
- 1 2 3 4 5 "Pam Boss Receives Preparata Medal" (PDF). 2013.
- 1 2 "Thermal and Nuclear Aspects of the Pd/D2O System. Volume 1. A Decade of Research at Navy Laboratories".
{{cite journal}}: Cite journal requires|journal=(help) - ↑ "Pd/D Co- Deposition" (PDF). 2021.
- 1 2 Mosier-Boss, Pamela A.; Szpak, Stanislaw; Gordon, Frank E.; Forsley, Lawrence P. G. (January 2009). "Triple tracks in CR-39 as the result of Pd-D Co-deposition: evidence of energetic neutrons". Die Naturwissenschaften. 96 (1): 135–142. Bibcode:2009NW.....96..135M. doi:10.1007/s00114-008-0449-x. ISSN 0028-1042. PMID 18828003. S2CID 11044813.
- ↑ Szpak, Stanislaw; Mosier-Boss, Pamela A.; Young, Charles; Gordon, Frank E. (2005-08-01). "Evidence of nuclear reactions in the Pd lattice". Naturwissenschaften. 92 (8): 394–397. Bibcode:2005NW.....92..394S. doi:10.1007/s00114-005-0008-7. ISSN 1432-1904. PMID 16052356. S2CID 13723567.
- ↑ Szpak, S.; Mosier-Boss, P. A.; Young, C.; Gordon, F. E. (2005-07-01). "The effect of an external electric field on surface morphology of co-deposited Pd/D films". Journal of Electroanalytical Chemistry. 580 (2): 284–290. doi:10.1016/j.jelechem.2005.03.039. ISSN 1572-6657.