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111-639: The need for a fusion pilot plant has been recognized throughout the program to develop fusion power . Most recently before the announcement of the Milestone-Based Fusion Development Program, in 2021 the National Academies of Sciences, Engineering, and Medicine (NASEM) released a report which highlighted the need for such a program and advised its creation. In 2022 the Biden administration and DOE announced

222-478: A coolant in the rotor and the stator in 1937 at Dayton , Ohio, owned by the Dayton Power & Light Co. This was justified by the high thermal conductivity and very low viscosity of hydrogen gas, thus lower drag than air. This is the most common coolant used for generators 60 MW and larger; smaller generators are usually air-cooled . The nickel–hydrogen battery was used for the first time in 1977 aboard

333-454: A fission-fusion hybrid . In these systems, the power output is enhanced by the fission events, and power is extracted using systems like those in conventional fission reactors. Designs that use other fuels, notably the proton-boron aneutronic fusion reaction, release much more of their energy in the form of charged particles. In these cases, power extraction systems based on the movement of these charges are possible. Direct energy conversion

444-479: A mixture of the two ), which react more easily than protium (the most common hydrogen isotope ) and produce a helium nucleus and an energized neutron , to allow them to reach the Lawson criterion requirements with less extreme conditions. Most designs aim to heat their fuel to around 100 million kelvins, which presents a major challenge in producing a successful design. Tritium is extremely rare on Earth, having

555-465: A nucleus which is usually composed of one proton. That is why H is often called a proton. This species is central to discussion of acids . Under the Brønsted–Lowry acid–base theory , acids are proton donors, while bases are proton acceptors. A bare proton, H , cannot exist in solution or in ionic crystals because of its strong attraction to other atoms or molecules with electrons. Except at

666-411: A probability distribution . If the plasma is thermalized , the distribution looks like a Gaussian curve , or Maxwell–Boltzmann distribution . In this case, it is useful to use the average particle cross section over the velocity distribution. This is entered into the volumetric fusion rate: where: The Lawson criterion considers the energy balance between the energy produced in fusion reactions to

777-494: A stoichiometric quantity of hydrogen at the anode. For hydrides other than group 1 and 2 metals, the term is quite misleading, considering the low electronegativity of hydrogen. An exception in group 2 hydrides is BeH 2 , which is polymeric. In lithium aluminium hydride , the [AlH 4 ] anion carries hydridic centers firmly attached to the Al(III). Although hydrides can be formed with almost all main-group elements,

888-479: A tokamak -based reactor. The system was able to manipulate the magnetic coils to manage the plasma. The system was able to continuously adjust to maintain appropriate behavior (more complex than step-based systems). In 2014, Google began working with California-based fusion company TAE Technologies to control the Joint European Torus (JET) to predict plasma behavior. DeepMind has also developed

999-473: A 1.5 nanosecond laser fire, 100 times greater than reported in previous experiments. Structural material stability is a critical issue. Materials that can survive the high temperatures and neutron bombardment experienced in a fusion reactor are considered key to success. The principal issues are the conditions generated by the plasma, neutron degradation of wall surfaces, and the related issue of plasma-wall surface conditions. Reducing hydrogen permeability

1110-656: A Bold Decadal Vision for Commercial Fusion Energy which included plans to fund support for pilot plant development program. The funding opportunity announcement (FOA) was announced by the US Department of Energy in September 2022, and $ 50 million was earmarked for the program. Applications were received in December 2022. Eight companies were selected for negotiation in May 2023. However, agreements were not signed with

1221-457: A Russian and Japanese company, developed a new manufacturing process for making superconducting YBCO wire for fusion reactors. This new wire was shown to conduct between 700 and 2000 Amps per square millimeter. The company was able to produce 186 miles of wire in nine months. Even on smaller production scales, the containment apparatus is blasted with matter and energy. Designs for plasma containment must consider: Hydrogen Hydrogen

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1332-575: A confined environment with sufficient temperature , pressure , and confinement time to create a plasma in which fusion can occur. The combination of these figures that results in a power-producing system is known as the Lawson criterion . In stars the most common fuel is hydrogen , and gravity provides extremely long confinement times that reach the conditions needed for fusion energy production. Proposed fusion reactors generally use heavy hydrogen isotopes such as deuterium and tritium (and especially

1443-461: A control scheme with TCV . The diagnostics of a fusion scientific reactor are extremely complex and varied. The diagnostics required for a fusion power reactor will be various but less complicated than those of a scientific reactor as by the time of commercialization, many real-time feedback and control diagnostics will have been perfected. However, the operating environment of a commercial fusion reactor will be harsher for diagnostic systems than in

1554-437: A fire. Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions: Many metals such as zirconium undergo a similar reaction with water leading to the production of hydrogen. François Isaac de Rivaz built the first de Rivaz engine , an internal combustion engine powered by a mixture of hydrogen and oxygen in 1806. Edward Daniel Clarke invented

1665-549: A half life of only ~12.3 years. Consequently, during the operation of envisioned fusion reactors, known as breeder reactors, helium cooled pebble beds (HCPBs) are subjected to neutron fluxes to generate tritium to complete the fuel cycle. As a source of power, nuclear fusion has a number of potential advantages compared to fission . These include reduced radioactivity in operation, little high-level nuclear waste , ample fuel supplies (assuming tritium breeding or some forms of aneutronic fuels ), and increased safety. However,

1776-407: A machine holding a thermalized and quasi- neutral plasma has to generate enough energy to overcome its energy losses. The amount of energy released in a given volume is a function of the temperature, and thus the reaction rate on a per-particle basis, the density of particles within that volume, and finally the confinement time, the length of time that energy stays within the volume. This is known as

1887-448: A monatomic gas at cryogenic temperatures. According to quantum theory, this behavior arises from the spacing of the (quantized) rotational energy levels, which are particularly wide-spaced in H 2 because of its low mass. These widely spaced levels inhibit equal partition of heat energy into rotational motion in hydrogen at low temperatures. Diatomic gases composed of heavier atoms do not have such widely spaced levels and do not exhibit

1998-545: A partial negative charge. These compounds are often known as hydrides . Hydrogen forms many compounds with carbon called the hydrocarbons , and even more with heteroatoms that, due to their association with living things, are called organic compounds . The study of their properties is known as organic chemistry and their study in the context of living organisms is called biochemistry . By some definitions, "organic" compounds are only required to contain carbon. However, most of them also contain hydrogen, and because it

2109-477: A partial positive charge. When bonded to a more electronegative element, particularly fluorine , oxygen , or nitrogen , hydrogen can participate in a form of medium-strength noncovalent bonding with another electronegative element with a lone pair, a phenomenon called hydrogen bonding that is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as metals and metalloids , where it takes on

2220-545: A plasma oscillating device, a magnetically shielded-grid, a penning trap , the polywell , and the F1 cathode driver concept. The fuels considered for fusion power have all been light elements like the isotopes of hydrogen— protium , deuterium , and tritium . The deuterium and helium-3 reaction requires helium-3, an isotope of helium so scarce on Earth that it would have to be mined extraterrestrially or produced by other nuclear reactions. Ultimately, researchers hope to adopt

2331-405: A proton and an electron, the hydrogen atom , together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. Furthermore, study of the corresponding simplicity of the hydrogen molecule and the corresponding cation H + 2 brought understanding of the nature of the chemical bond , which followed shortly after

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2442-476: A scientific reactor because continuous operations may involve higher plasma temperatures and higher levels of neutron irradiation. In many proposed approaches, commercialization will require the additional ability to measure and separate diverter gases, for example helium and impurities, and to monitor fuel breeding, for instance the state of a tritium breeding liquid lithium liner. The following are some basic techniques. Neutron blankets absorb neutrons, which heats

2553-452: A series of D-T tests at JET , the vacuum vessel was sufficiently radioactive that it required remote handling for the year following the tests. In a production setting, the neutrons would react with lithium in the breeding blanket composed of lithium ceramic pebbles or liquid lithium, yielding tritium. The energy of the neutrons ends up in the lithium, which would then be transferred to drive electrical production. The lithium blanket protects

2664-538: A serious incident. Hydrogen-lifted airships were used as observation platforms and bombers during the war. The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H 2

2775-413: A shell, driving the shell to radiate x-rays , which then implode the pellet. The beams are commonly laser beams, but ion and electron beams have been investigated. Electrostatic confinement fusion devices use electrostatic fields. The best known is the fusor . This device has a cathode inside an anode wire cage. Positive ions fly towards the negative inner cage, and are heated by the electric field in

2886-440: A similar experiment with iron and sulfuric acid. However, in all likelihood, "sulfureous" should here be understood to mean "combustible". In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "inflammable air". He speculated that "inflammable air" was in fact identical to the hypothetical substance " phlogiston " and further finding in 1781 that

2997-498: A smaller portion comes from energy-intensive methods such as the electrolysis of water . Its main industrial uses include fossil fuel processing, such as hydrocracking , and ammonia production , with emerging uses in fuel cells for electricity generation and as a heat source. When used in fuel cells, hydrogen's only emission at point of use is water vapor, though combustion can produce nitrogen oxides . Hydrogen's interaction with metals may cause embrittlement . Hydrogen gas

3108-471: A spark or flame, they do not react at room temperature in the absence of a catalyst. The ground state energy level of the electron in a hydrogen atom is −13.6  eV , equivalent to an ultraviolet photon of roughly 91 nm wavelength. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, in which the electron "orbits" the proton, like how Earth orbits

3219-450: A species. To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the " hydronium ion" ( [H 3 O] ). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into clusters that form species closer to [H 9 O 4 ] . Other oxonium ions are found when water

3330-406: A spin singlet state having spin S = 0 {\displaystyle S=0} . The equilibrium ratio of ortho- to para-hydrogen depends on temperature. At room temperature or warmer, equilibrium hydrogen gas contains about 25% of the para form and 75% of the ortho form. The ortho form is an excited state , having higher energy than the para form by 1.455 kJ/mol, and it converts to

3441-422: A surface of the device, and transfer a portion of their kinetic energy to the other atoms. The rate of conduction is also based on the temperature and density. Radiation is energy that leaves the cloud as light. Radiation also increases with temperature as well as the mass of the ions. Fusion power systems must operate in a region where the rate of fusion is higher than the losses. The Lawson criterion argues that

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3552-438: A term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a negative or anionic character, denoted H ; and is used when hydrogen forms a compound with a more electropositive element. The existence of the hydride anion , suggested by Gilbert N. Lewis in 1916 for group 1 and 2 salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing

3663-423: A variety of heating methods that were developed in the early 1970s. In modern machines, as of 2019 , the major remaining issue was the confinement time. Plasmas in strong magnetic fields are subject to a number of inherent instabilities, which must be suppressed to reach useful durations. One way to do this is to simply make the reactor volume larger, which reduces the rate of leakage due to classical diffusion . This

3774-482: A while before caus'd to be purposely fil'd off from a piece of good steel. This metalline powder being moistn'd in the viol with a little of the menstruum, was afterwards drench'd with more; whereupon the mixture grew very hot, and belch'd up copious and stinking fumes; which whether they consisted altogether of the volatile sulfur of the Mars [iron], or of metalline steams participating of a sulfureous nature, and join'd with

3885-421: Is endothermic , requiring an input of energy. The heavy nuclei bigger than iron have many more protons resulting in a greater repulsive force. For nuclei lighter than iron-56, the reaction is exothermic , releasing energy when they fuse. Since hydrogen has a single proton in its nucleus, it requires the least effort to attain fusion, and yields the most net energy output. Also since it has one electron, hydrogen

3996-579: Is exothermic and produces enough heat to evaporate most of the liquid if not converted first to parahydrogen during the cooling process. Catalysts for the ortho-para interconversion, such as ferric oxide and activated carbon compounds, are used during hydrogen cooling to avoid this loss of liquid. While H 2 is not very reactive under standard conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative , such as halogens (F, Cl, Br, I), or oxygen ; in these compounds hydrogen takes on

4107-428: Is a chemical element ; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions , is a gas of diatomic molecules with the formula H 2 , sometimes called dihydrogen , but more commonly called hydrogen gas , molecular hydrogen or simply hydrogen. It is colorless, odorless, non-toxic, and highly combustible . Constituting about 75% of all normal matter , hydrogen

4218-490: 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 2024, no device has reached net power, although net positive reactions have been achieved. Fusion processes require fuel and

4329-471: Is also common in research. The optimum energy to initiate this reaction is 15 keV, only slightly higher than that for the D-T reaction. The first branch produces tritium, so that a D-D reactor is not tritium-free, even though it does not require an input of tritium or lithium. Unless the tritons are quickly removed, most of the tritium produced is burned in the reactor, which reduces the handling of tritium, with

4440-497: Is called "tritium suppressed fusion". The removed tritium decays to He with a 12.5 year half life. By recycling the He decay into the reactor, the fusion reactor does not require materials resistant to fast neutrons. Assuming complete tritium burn-up, the reduction in the fraction of fusion energy carried by neutrons would be only about 18%, so that the primary advantage of the D-D fuel cycle

4551-505: Is crucial in acid-base reactions , which mainly involve proton exchange among soluble molecules. In ionic compounds , hydrogen can take the form of either a negatively charged anion , where it is known as hydride , or as a positively charged cation , H . The cation, usually just a proton (symbol p ), exhibits specific behavior in aqueous solutions and in ionic compounds involves screening of its electric charge by surrounding polar molecules or anions. Hydrogen's unique position as

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4662-468: Is detected in order to probe primordial hydrogen. The large amount of neutral hydrogen found in the damped Lyman-alpha systems is thought to dominate the cosmological baryonic density of the universe up to a redshift of z  = 4. Under ordinary conditions on Earth, elemental hydrogen exists as the diatomic gas, H 2 . Hydrogen gas is very rare in Earth's atmosphere (around 0.53 ppm on

4773-503: Is for the first period of performance. Subsequent periods of performance have not as of 2024 been announced, appropriated, or awarded. The applicants were encouraged to propose collaborations with US national laboratories, with which the DOE would contract separately and pay directly. Oak Ridge National Laboratory will work with six of the eight companies. The year-long gap between the announcement of awardees and their signing agreements with

4884-428: Is formed by oxidation alone. Alternative methods utilize specific gas environments with strong magnetic and electric fields. Assessment of barrier performance represents an additional challenge. Classical coated membranes gas permeation continues to be the most reliable method to determine hydrogen permeation barrier (HPB) efficiency. In 2021, in response to increasing numbers of designs for fusion power reactors for 2040,

4995-400: Is highly flammable: Enthalpy of combustion : −286 kJ/mol. Hydrogen gas forms explosive mixtures with air in concentrations from 4–74% and with chlorine at 5–95%. The hydrogen autoignition temperature , the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to

5106-453: Is in acidic solution with other solvents. Although exotic on Earth, one of the most common ions in the universe is the H + 3 ion, known as protonated molecular hydrogen or the trihydrogen cation. Hydrogen has three naturally occurring isotopes, denoted H , H and H . Other, highly unstable nuclei ( H to H ) have been synthesized in the laboratory but not observed in nature. Unique among

5217-405: Is increasing interest in magnetized target fusion and inertial electrostatic confinement , and new variations of the stellarator. Fusion reactions occur when two or more atomic nuclei come close enough for long enough that the nuclear force pulling them together exceeds the electrostatic force pushing them apart, fusing them into heavier nuclei. For nuclei heavier than iron-56 , the reaction

5328-525: Is seen as crucial to hydrogen recycling and control of the tritium inventory. Materials with the lowest bulk hydrogen solubility and diffusivity provide the optimal candidates for stable barriers. A few pure metals, including tungsten and beryllium, and compounds such as carbides, dense oxides, and nitrides have been investigated. Research has highlighted that coating techniques for preparing well-adhered and perfect barriers are of equivalent importance. The most attractive techniques are those in which an ad-layer

5439-484: Is soluble in both nanocrystalline and amorphous metals . Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice . These properties may be useful when hydrogen is purified by passage through hot palladium disks, but the gas's high solubility is a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks. Hydrogen compounds are often called hydrides ,

5550-611: Is still considerably higher compared to fission reactors. Because the confinement properties of the tokamak and laser pellet fusion are marginal, most proposals for aneutronic fusion are based on radically different confinement concepts, such as the Polywell and the Dense Plasma Focus . In 2013, a research team led by Christine Labaune at École Polytechnique , reported a new fusion rate record for proton-boron fusion, with an estimated 80 million fusion reactions during

5661-481: Is still used, in preference to non-flammable but more expensive helium, as a lifting gas for weather balloons . Deuterium was discovered in December 1931 by Harold Urey , and tritium was prepared in 1934 by Ernest Rutherford , Mark Oliphant , and Paul Harteck . Heavy water , which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. The first hydrogen-cooled turbogenerator went into service using gaseous hydrogen as

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5772-404: Is that tritium breeding is not required. Other advantages are independence from lithium resources and a somewhat softer neutron spectrum. The disadvantage of D-D compared to D-T is that the energy confinement time (at a given pressure) must be 30 times longer and the power produced (at a given pressure and volume) is 68 times less. Assuming complete removal of tritium and He recycling, only 6% of

5883-490: Is the most abundant chemical element in the universe . Stars , including the Sun , mainly consist of hydrogen in a plasma state , while on Earth, hydrogen is found in water , organic compounds , as dihydrogen , and in other molecular forms . The most common isotope of hydrogen (protium, H) consists of one proton , one electron , and no neutrons . In the early universe , the formation of hydrogen's protons occurred in

5994-412: Is the carbon-hydrogen bond that gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated pathways that seldom involve elemental hydrogen. Hydrogen is highly soluble in many rare earth and transition metals and

6105-439: Is the easiest fuel to fully ionize. The repulsive electrostatic interaction between nuclei operates across larger distances than the strong force, which has a range of roughly one femtometer —the diameter of a proton or neutron. The fuel atoms must be supplied enough kinetic energy to approach one another closely enough for the strong force to overcome the electrostatic repulsion in order to initiate fusion. The " Coulomb barrier "

6216-527: Is the quantity of kinetic energy required to move the fuel atoms near enough. Atoms can be heated to extremely high temperatures or accelerated in a particle accelerator to produce this energy. An atom loses its electrons once it is heated past its ionization energy . An ion is the name for the resultant bare nucleus. The result of this ionization is plasma, which is a heated cloud of ions and free electrons that were formerly bound to them. Plasmas are electrically conducting and magnetically controlled because

6327-404: Is unaffected by the confinement scheme. In most designs, it is captured in a thick "blanket" of lithium surrounding the reactor core. When struck by a high-energy neutron, the blanket heats up. It is then actively cooled with a working fluid that drives a turbine to produce power. Another design proposed to use the neutrons to breed fission fuel in a blanket of nuclear waste , a concept known as

6438-404: Is why ITER is so large. In contrast, inertial confinement systems approach useful triple product values via higher density, and have short confinement intervals. In NIF , the initial frozen hydrogen fuel load has a density less than water that is increased to about 100 times the density of lead. In these conditions, the rate of fusion is so high that the fuel fuses in the microseconds it takes for

6549-502: The Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated. The visible flames in the photographs were the result of carbon compounds in the airship skin burning. H 2 is unreactive compared to diatomic elements such as halogens or oxygen. The thermodynamic basis of this low reactivity is the very strong H–H bond, with a bond dissociation energy of 435.7 kJ/mol. The kinetic basis of

6660-579: The International Union of Pure and Applied Chemistry (IUPAC) allows any of D, T, H , and H to be used, though H and H are preferred. The exotic atom muonium (symbol Mu), composed of an anti muon and an electron , can also be considered a light radioisotope of hydrogen. Because muons decay with lifetime 2.2  µs , muonium is too unstable for observable chemistry. Nevertheless, muonium compounds are important test cases for quantum simulation , due to

6771-676: The United Kingdom Atomic Energy Authority published the UK Fusion Materials Roadmap 2021–2040 , focusing on five priority areas, with a focus on tokamak family reactors: In a plasma that is embedded in a magnetic field (known as a magnetized plasma) the fusion rate scales as the magnetic field strength to the 4th power. For this reason, many fusion companies that rely on magnetic fields to control their plasma are trying to develop high temperature superconducting devices. In 2021, SuperOx,

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6882-462: The tokamak approach, 2 companies pursuing the stellarator approach, 2 companies pursuing inertial confinement fusion , one company pursuing the magnetic mirror approach, and one company pursuing the Z-pinch approach. The program is structured as a public–private partnership between the DOE and the awardees. The companies unlock matching funds upon completion of quantitative milestones, up to

6993-415: The uranium enrichment process. Tritium is a natural isotope of hydrogen, but because it has a short half-life of 12.32 years, it is hard to find, store, produce, and is expensive. Consequently, the deuterium-tritium fuel cycle requires the breeding of tritium from lithium using one of the following reactions: The reactant neutron is supplied by the D-T fusion reaction shown above, and the one that has

7104-431: The "planetary orbit" differs from electron motion. Molecular H 2 exists as two spin isomers , i.e. compounds that differ only in the spin states of their nuclei. In the orthohydrogen form, the spins of the two nuclei are parallel, forming a spin triplet state having a total molecular spin S = 1 {\displaystyle S=1} ; in the parahydrogen form the spins are antiparallel and form

7215-460: The "triple product": the plasma density, temperature, and confinement time. In magnetic confinement, the density is low, on the order of a "good vacuum". For instance, in the ITER device the fuel density is about 1.0 × 10 m , which is about one-millionth atmospheric density. This means that the temperature and/or confinement time must increase. Fusion-relevant temperatures have been achieved using

7326-531: The DOE was apparently due to a dispute over how companies' intellectual property would be treated under the award. Reporting stated that the companies' rights to existing and subject intellectual property was not sufficiently safeguarded under the DOE's initial proposed terms. At the time of the announcement, the total private investment in Commonwealth Fusion Systems was larger than $ 2 billion. Fusion pilot plant Fusion power

7437-479: The Sun and other stars). The charged particles are highly influenced by magnetic and electric fields. For example, in the solar wind they interact with the Earth's magnetosphere giving rise to Birkeland currents and the aurora . Hydrogen is found in the neutral atomic state in the interstellar medium because the atoms seldom collide and combine. They are the source of the 21-cm hydrogen line at 1420 MHz that

7548-457: The Sun and the CNO cycle of nuclear fusion in case of stars more massive than the Sun . Throughout the universe, hydrogen is mostly found in the atomic and plasma states, with properties quite distinct from those of molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from

7659-464: The Sun. However, the electron and proton are held together by electrostatic attraction, while planets and celestial objects are held by gravity . Due to the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. A more accurate description of

7770-614: The U.S. Navy's Navigation technology satellite-2 (NTS-2). The International Space Station , Mars Odyssey and the Mars Global Surveyor are equipped with nickel-hydrogen batteries. In the dark part of its orbit, the Hubble Space Telescope is also powered by nickel-hydrogen batteries, which were finally replaced in May 2009, more than 19 years after launch and 13 years beyond their design life. Because of its simple atomic structure, consisting only of

7881-640: The awardees until more than a year later in June 2024, reportedly due to concerns over how intellectual property would be handled. In June 2024, at a White House summit the Department of Energy announced that all eight companies had successfully concluded detailed milestones negotiations with the federal government and that agreements had been signed to commence the Milestone Program. The eight awardees are: The awardees include 2 companies pursuing

7992-410: The blanket. Power can be extracted from the blanket in various ways: Confinement refers to all the conditions necessary to keep a plasma dense and hot long enough to undergo fusion. General principles: To produce self-sustaining fusion, part of the energy released by the reaction must be used to heat new reactants and maintain the conditions for fusion. Magnetic mirror effect. If a particle follows

8103-448: The charges are separated. This is used by several fusion devices to confine the hot particles. A reaction's cross section , denoted σ, measures the probability that a fusion reaction will happen. This depends on the relative velocity of the two nuclei. Higher relative velocities generally increase the probability, but the probability begins to decrease again at very high energies. In a plasma, particle velocity can be characterized using

8214-405: The disadvantage of producing more, and higher-energy, neutrons. The neutron from the second branch of the D-D reaction has an energy of only 2.45 MeV (0.393 pJ), while the neutron from the D-T reaction has an energy of 14.1 MeV (2.26 pJ), resulting in greater isotope production and material damage. When the tritons are removed quickly while allowing the He to react, the fuel cycle

8325-430: The elements, distinct names are assigned to its isotopes in common use. During the early study of radioactivity, heavy radioisotopes were given their own names, but these are mostly no longer used. The symbols D and T (instead of H and H ) are sometimes used for deuterium and tritium, but the symbol P was already used for phosphorus and thus was not available for protium. In its nomenclatural guidelines,

8436-448: The energy being lost to the environment. In order to generate usable energy, a system would have to produce more energy than it loses. Lawson assumed an energy balance , shown below. where: The rate of fusion, and thus P fusion , depends on the temperature and density of the plasma. The plasma loses energy through conduction and radiation . Conduction occurs when ions , electrons , or neutrals impact other substances, typically

8547-485: The field line and enters a region of higher field strength, the particles can be reflected. Several devices apply this effect. The most famous was the magnetic mirror machines, a series of devices built at LLNL from the 1960s to the 1980s. Other examples include magnetic bottles and Biconic cusp . Because the mirror machines were straight, they had some advantages over ring-shaped designs. The mirrors were easier to construct and maintain and direct conversion energy capture

8658-497: The first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard . German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen that later were called Zeppelins ; the first of which had its maiden flight in 1900. Regularly scheduled flights started in 1910 and by the outbreak of World War I in August 1914, they had carried 35,000 passengers without

8769-496: The first second after the Big Bang ; neutral hydrogen atoms only formed about 370,000 years later during the recombination epoch as the universe cooled and plasma had cooled enough for electrons to remain bound to protons. Hydrogen, typically nonmetallic except under extreme pressure , readily forms covalent bonds with most nonmetals, contributing to the formation of compounds like water and various organic substances. Its role

8880-445: The full award amount. The program is structured in three periods of performance: One spanning the first 18 months, one spanning the second 18 months, and one spanning the remaining 24 months of the five-year term. The first period of performance will presumably end around the end of 2025, assuming a start date based on the June 2024 announcement. Only the first period of performance has been announced and awarded. The $ 46 million number

8991-410: The fusion energy is carried by neutrons. The tritium-suppressed D-D fusion requires an energy confinement that is 10 times longer compared to D-T and double the plasma temperature. A second-generation approach to controlled fusion power involves combining helium-3 ( He) and deuterium ( H): This reaction produces He and a high-energy proton. As with the p- B aneutronic fusion fuel cycle, most of

9102-462: The gas produces water when burned. He is usually given credit for the discovery of hydrogen as an element. In 1783, Antoine Lavoisier identified the element that came to be known as hydrogen when he and Laplace reproduced Cavendish's finding that water is produced when hydrogen is burned. Lavoisier produced hydrogen for his experiments on mass conservation by reacting a flux of steam with metallic iron through an incandescent iron tube heated in

9213-455: The greatest energy yield. The reaction with Li is exothermic , providing a small energy gain for the reactor. The reaction with Li is endothermic , but does not consume the neutron. Neutron multiplication reactions are required to replace the neutrons lost to absorption by other elements. Leading candidate neutron multiplication materials are beryllium and lead , but the Li reaction helps to keep

9324-406: The heat generated by the reactions to blow the fuel apart. Although NIF is also large, this is a function of its "driver" design, not inherent to the fusion process. Multiple approaches have been proposed to capture the energy that fusion produces. The simplest is to heat a fluid. The commonly targeted D-T reaction releases much of its energy as fast-moving neutrons. Electrically neutral, the neutron

9435-427: The high temperatures associated with plasmas, such protons cannot be removed from the electron clouds of atoms and molecules, and will remain attached to them. However, the term 'proton' is sometimes used loosely and metaphorically to refer to positively charged or cationic hydrogen attached to other species in this fashion, and as such is denoted " H " without any implication that any single protons exist freely as

9546-503: The hydrogen atom comes from a quantum analysis that uses the Schrödinger equation , Dirac equation or Feynman path integral formulation to calculate the probability density of the electron around the proton. The most complex formulas include the small effects of special relativity and vacuum polarization . In the quantum mechanical treatment, the electron in a ground state hydrogen atom has no angular momentum—illustrating how

9657-399: The hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823. Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask . He produced solid hydrogen the next year. The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for

9768-400: The low reactivity is the nonpolar nature of H 2 and its weak polarizability. It spontaneously reacts with chlorine and fluorine to form hydrogen chloride and hydrogen fluoride , respectively. The reactivity of H 2 is strongly affected by the presence of metal catalysts. Thus, while mixtures of H 2 with O 2 or air combust readily when heated to at least 500°C by

9879-402: The mass difference between the antimuon and the proton, and IUPAC nomenclature incorporates such hypothetical compounds as muonium chloride (MuCl) and sodium muonide (NaMu), analogous to hydrogen chloride and sodium hydride respectively. Table of thermal and physical properties of hydrogen (H 2 ) at atmospheric pressure: In 1671, Irish scientist Robert Boyle discovered and described

9990-481: The mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as dark matter and dark energy . Hydrogen is found in great abundance in stars and gas giant planets. Molecular clouds of H 2 are associated with star formation . Hydrogen plays a vital role in powering stars through the proton-proton reaction in case of stars with very low to approximately 1 mass of

10101-597: The most reactive aneutronic fuel is He. However, obtaining reasonable quantities of He implies large scale extraterrestrial mining on the Moon or in the atmosphere of Uranus or Saturn. Therefore, the most promising candidate fuel for such fusion is fusing the readily available protium (i.e. a proton ) and boron . Their fusion releases no neutrons, but produces energetic charged alpha (helium) particles whose energy can directly be converted to electrical power: Side reactions are likely to yield neutrons that carry only about 0.1% of

10212-501: The naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine , compared to the highly visible plume of a Space Shuttle Solid Rocket Booster , which uses an ammonium perchlorate composite . The detection of a burning hydrogen leak, may require a flame detector ; such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of

10323-417: The necessary combination of temperature, pressure, and duration has proven to be difficult to produce in a practical and economical manner. A second issue that affects common reactions is managing neutrons that are released during the reaction, which over time degrade many common materials used within the reaction chamber. Fusion researchers have investigated various confinement concepts. The early emphasis

10434-415: The neutron population high. Natural lithium is mainly Li, which has a low tritium production cross section compared to Li so most reactor designs use breeding blankets with enriched Li. Drawbacks commonly attributed to D-T fusion power include: The neutron flux expected in a commercial D-T fusion reactor is about 100 times that of fission power reactors, posing problems for material design . After

10545-649: The number and combination of possible compounds varies widely; for example, more than 100 binary borane hydrides are known, but only one binary aluminium hydride. Binary indium hydride has not yet been identified, although larger complexes exist. In inorganic chemistry , hydrides can also serve as bridging ligands that link two metal centers in a coordination complex . This function is particularly common in group 13 elements , especially in boranes ( boron hydrides) and aluminium complexes, as well as in clustered carboranes . Oxidation of hydrogen removes its electron and gives H , which contains no electrons and

10656-655: The only neutral atom for which the Schrödinger equation can be directly solved, has significantly contributed to the foundational principles of quantum mechanics through the exploration of its energetics and chemical bonding . Hydrogen gas was first produced artificially in the early 16th century by reacting acids with metals. Henry Cavendish , in 1766–81, identified hydrogen gas as a distinct substance and discovered its property of producing water when burned; hence its name means "water-former" in Greek. Most hydrogen production occurs through steam reforming of natural gas ;

10767-574: The outer portions of the reactor from the neutron flux. Newer designs, the advanced tokamak in particular, use lithium inside the reactor core as a design element. The plasma interacts directly with the lithium, preventing a problem known as "recycling". The advantage of this design was demonstrated in the Lithium Tokamak Experiment . Fusing two deuterium nuclei is the second easiest fusion reaction. The reaction has two branches that occur with nearly equal probability: This reaction

10878-420: The para form over the course of several minutes when cooled to low temperature. The thermal properties of the forms differ because they differ in their allowed rotational quantum states , resulting in different thermal properties such as the heat capacity. The ortho-to-para ratio in H 2 is an important consideration in the liquefaction and storage of liquid hydrogen : the conversion from ortho to para

10989-453: The power, which means that neutron scattering is not used for energy transfer and material activation is reduced several thousand-fold. The optimum temperature for this reaction of 123 keV is nearly ten times higher than that for pure hydrogen reactions, and energy confinement must be 500 times better than that required for the D-T reaction. In addition, the power density is 2500 times lower than for D-T, although per unit mass of fuel, this

11100-420: The process. If they miss the inner cage they can collide and fuse. Ions typically hit the cathode, however, creating prohibitory high conduction losses. Fusion rates in fusors are low because of competing physical effects, such as energy loss in the form of light radiation. Designs have been proposed to avoid the problems associated with the cage, by generating the field using a non-neutral cloud. These include

11211-447: The protium–boron-11 reaction, because it does not directly produce neutrons, although side reactions can. The easiest nuclear reaction, at the lowest energy, is D+T: This reaction is common in research, industrial and military applications, usually as a neutron source. Deuterium is a naturally occurring isotope of hydrogen and is commonly available. The large mass ratio of the hydrogen isotopes makes their separation easy compared to

11322-477: The quantum mechanical treatment of the hydrogen atom had been developed in the mid-1920s. One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H 2 unaccountably departs from that of a diatomic gas below room temperature and begins to increasingly resemble that of

11433-502: The reaction between iron filings and dilute acids , which results in the production of hydrogen gas. Having provided a saline spirit [hydrochloric acid], which by an uncommon way of preparation was made exceeding sharp and piercing, we put into a vial, capable of containing three or four ounces of water, a convenient quantity of filings of steel, which were not such as are commonly sold in shops to Chymists and Apothecaries, (those being usually not free enough from rust) but such as I had

11544-448: The reaction energy is released as charged particles, reducing activation of the reactor housing and potentially allowing more efficient energy harvesting (via any of several pathways). In practice, D-D side reactions produce a significant number of neutrons, leaving p- B as the preferred cycle for aneutronic fusion. Both material science problems and non-proliferation concerns are greatly diminished by aneutronic fusion . Theoretically,

11655-506: The saline exhalations of the menstruum, is not necessary to be here discuss'd. But whencesoever this stinking smoak proceeded, so inflammable it was, that upon the approach of a lighted candle to it, it would readily enough take fire, and burn with a blewish and somewhat greenish flame at the mouth of the viol for a good while together; and that, though with little light, yet with more strength than one would easily suspect. The word "sulfureous" may be somewhat confusing, especially since Boyle did

11766-405: The same effect. Antihydrogen ( H ) is the antimatter counterpart to hydrogen. It consists of an antiproton with a positron . Antihydrogen is the only type of antimatter atom to have been produced as of 2015 . Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and >90% by number of atoms. Most of

11877-639: The spheromak, attempt to combine the advantages of toroidal magnetic surfaces with those of a simply connected (non-toroidal) machine, resulting in a mechanically simpler and smaller confinement area. Inertial confinement is the use of rapid implosion to heat and confine plasma. A shell surrounding the fuel is imploded using a direct laser blast (direct drive), a secondary x-ray blast (indirect drive), or heavy beams. The fuel must be compressed to about 30 times solid density with energetic beams. Direct drive can in principle be efficient, but insufficient uniformity has prevented success. Indirect drive uses beams to heat

11988-800: Was developed at Lawrence Livermore National Laboratory (LLNL) in the 1980s as a method to maintain a voltage directly using fusion reaction products. This has demonstrated energy capture efficiency of 48 percent. Plasma is an ionized gas that conducts electricity. In bulk, it is modeled using magnetohydrodynamics , which is a combination of the Navier–Stokes equations governing fluids and Maxwell's equations governing how magnetic and electric fields behave. Fusion exploits several plasma properties, including: Many approaches, equipment, and mechanisms are employed across multiple projects to address fusion heating, measurement, and power production. A deep reinforcement learning system has been used to control

12099-417: Was easier to implement. Poor confinement has led this approach to be abandoned, except in the polywell design. Magnetic loops bend the field lines back on themselves, either in circles or more commonly in nested toroidal surfaces. The most highly developed systems of this type are the tokamak , the stellarator, and the reversed field pinch. Compact toroids , especially the field-reversed configuration and

12210-583: Was on three main systems: z-pinch , stellarator , and magnetic mirror . The current leading designs are the tokamak and inertial confinement (ICF) by laser . Both designs are under research at very large scales, most notably the ITER tokamak in France and the National Ignition Facility (NIF) laser in the United States. Researchers are also studying other designs that may offer less expensive approaches. Among these alternatives, there

12321-527: Was used in the Hindenburg airship, which was destroyed in a midair fire over New Jersey on 6 May 1937. The incident was broadcast live on radio and filmed. Ignition of leaking hydrogen is widely assumed to be the cause, but later investigations pointed to the ignition of the aluminized fabric coating by static electricity . But the damage to hydrogen's reputation as a lifting gas was already done and commercial hydrogen airship travel ceased . Hydrogen

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