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Compact Ignition Tokamak
The Compact Ignition Tokamak (CIT) was a plasma physics experiment that was designed but not built. It was designed by an inter-organizational team in the USA led by Princeton Plasma Physics Laboratory. The experiment was designed to achieve a self-sustaining Thermonuclear fusion reaction (ignition) in a Tokamak with the minimum possible budget. History CIT was to be the successor experiment to the Tokamak Fusion Test Reactor (TFTR). Where TFTR was designed to achieve Q>1 (more fusion power produced by the plasma than injected into the plasma), CIT was designed to achieve ignition, here defined as Q>10 (fusion power produced is more than ten times the heating power). Design of CIT began in 1986, at which point it was expected that construction would begin in 1988 and complete in 1993. The estimated cost of construction was $285 Million in 1986 dollars. As development progressed, the tokamak design grew in size, magnetic field, and heating power. At some point in the early 1990 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties in the direction parallel to the magnetic field are different from those perpendicular to it. While electric fields in plasmas are usually small due to the plasma high conductivity, the electric field associated with a plasma moving with velocity \mathbf in the magnetic field \mathbf is given by the usual Lorentz force, Lorentz formula \mathbf = -\mathbf\times\mathbf, and is not affected by Debye shielding. Mathematical descriptions To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton Plasma Physics Laboratory
Princeton Plasma Physics Laboratory (PPPL) is a United States Department of Energy national laboratory for plasma physics and nuclear fusion science. Its primary mission is research into and development of fusion as an energy source. It is known in particular for the development of the stellarator and tokamak designs, along with numerous fundamental advances in plasma physics and the exploration of many other plasma confinement concepts. PPPL grew out of the top-secret Cold War project to control thermonuclear reactions, called Project Matterhorn. The focus of this program changed from H-bombs to fusion power in 1951, when Lyman Spitzer developed the stellarator concept and was granted funding from the Atomic Energy Commission to study the concept. This led to a series of machines in the 1950s and 60s. In 1961, after declassification, Project Matterhorn was renamed the Princeton Plasma Physics Laboratory. PPPL's stellarators proved unable to meet their performance goals. In 196 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermonuclear Fusion
Thermonuclear fusion is the process of atomic nuclei combining or “fusing” using high temperatures to drive them close enough together for this to become possible. There are two forms of thermonuclear fusion: ''uncontrolled'', in which the resulting energy is released in an uncontrolled manner, as it is in thermonuclear weapons ("hydrogen bombs") and in most stars; and ''controlled'', where the fusion reactions take place in an environment allowing some or all of the energy released to be harnessed for constructive purposes. Temperature requirements Temperature is a measure of the average kinetic energy of particles, so by heating the material it will gain energy. After reaching sufficient temperature, given by the Lawson criterion, the energy of accidental collisions within the plasma is high enough to overcome the Coulomb barrier and the particles may fuse together. In a deuterium–tritium fusion reaction, for example, the energy necessary to overcome the Coulomb barrie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamak
A tokamak (; russian: токамáк; otk, 𐱃𐰸𐰢𐰴, Toḳamaḳ) is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power. , it was the leading candidate for a practical fusion reactor. Tokamaks were initially conceptualized in the 1950s by Soviet physicists Igor Tamm and Andrei Sakharov, inspired by a letter by Oleg Lavrentiev. The first working tokamak was attributed to the work of Natan Yavlinsky on the T-1 in 1958. It had been demonstrated that a stable plasma equilibrium requires magnetic field lines that wind around the torus in a helix. Devices like the z-pinch and stellarator had attempted this, but demonstrated serious instabilities. It was the development of the concept now known as the safety factor (labelled ''q'' in mathematical notation) that guided tokamak development; by arranging the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamak Fusion Test Reactor
The Tokamak Fusion Test Reactor (TFTR) was an experimental tokamak built at Princeton Plasma Physics Laboratory (PPPL) circa 1980 and entering service in 1982. TFTR was designed with the explicit goal of reaching scientific breakeven, the point where the heat being released from the fusion reactions in the plasma is equal or greater than the heating being supplied to the plasma by external devices to warm it up. The TFTR never achieved this goal, but it did produce major advances in confinement time and energy density. It was the world's first magnetic fusion device to perform extensive scientific experiments with plasmas composed of 50/50 deuterium/tritium (D-T), the fuel mix required for practical fusion power production, and also the first to produce more than 10 MW of fusion power. It set several records for power output, maximum temperature, and fusion triple product. TFTR shut down in 1997 after fifteen years of operation. PPPL used the knowledge from TFTR to begin studying ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamak Physics Experiment
The Tokamak Physics Experiment (TPX) was a plasma physics experiment that was designed but not built. It was designed by an inter-organizational team in the USA led by Princeton Plasma Physics Laboratory. The experiment was designed to test theories about how Tokamaks would behave in a high-performance, steady-state regime. Goals TPX was to be the successor to the Tokamak Fusion Test Reactor (TFTR). While TFTR was designed to achieve Q>1 (more fusion power produced by the plasma than injected into the plasma), TFTR only operated for short pulses, and did not provide data from and experience with plasmas behave like those of an economic Fusion power reactor. Specifically, TPX was designed to fill this need. TPX was designed to test theories which suggested ways of making a future fusion power reactor compact, economic, and reliable. Specifically, TPX was designed to be near steady state, with pulse lengths of 1,000 seconds (more than 15 minutes). It was designed to operate at hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burning Plasma
Plasma, one of the four fundamental states of matter, consists of a gas of ions and free electrons. A burning plasma is one in which most of the plasma heating comes from fusion reactions involving thermal plasma ions. The Sun In the Sun and other similar stars, those fusion reactions involve hydrogen ions. The high temperatures needed to sustain fusion reactions are maintained by a self-heating process in which energy from the fusion reaction heats the thermal plasma ions via particle collisions. A plasma enters what scientists call the burning plasma regime when the self-heating power exceeds any external heating. The Sun is a burning plasma that has reached "ignition", meaning the Sun's plasma temperature is maintained solely by energy released from fusion. The Sun has been burning hydrogen for 4.5 billion years and is about halfway through its life cycle. The National Ignition Facility It was announced in 2022 that a burning plasma had been achieved at the National Ignitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGNITOR
Ignitor is the Italian name for a planned tokamak device, developed by ENEA. , the device has not been constructed. Started in 1977 by Prof. Bruno Coppi at MIT, Ignitor based on the 1970s Alcator machine at MIT which pioneered the high magnetic field approach to plasma magnetic confinement, continued with the Alcator C/C-Mod at MIT and the FT/FTU series of experiments. It was initially proposed to be built "in the area of the former Caorso nuclear power station". The currently intended location is at Troitsk near Moscow. Ignitor is designed to produce approximately 100 MW of fusion power despite its relatively small size. For comparison, the intended weight is 500 metric tons, while the ITER international reactor, expected to be the first tokamak to reach scientific breakeven, is some 19,000 tons. 2010 At a meeting with the scientific attachés of the European embassies in Moscow in early February 2010 Mikhail Kovalchuk, Director of the Kurchatov Institute, announced tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superconductivity
Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source. The superconductivity phenomenon was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. Like ferromagnetism and atomic spectral lines, superconductivity is a phenomenon which can only be explained by quantum mechanics. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Nitrogen
Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is widely used as a coolant. Physical properties The diatomic character of the N2 molecule is retained after liquefaction. The weak van der Waals interaction between the N2 molecules results in little interatomic interaction, manifested in its very low boiling point. The temperature of liquid nitrogen can readily be reduced to its freezing point by placing it in a vacuum chamber pumped by a vacuum pump. Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of nitrogen gas bubbles. This effect, known as the Leidenfrost effect, occurs when any liquid comes in contact with a surface which is significantly hotter than its boiling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohmic Heating
Joule heating, also known as resistive, resistance, or Ohmic heating, is the process by which the passage of an electric current through a conductor produces heat. Joule's first law (also just Joule's law), also known in countries of former USSR as the Joule–Lenz law,Джоуля — Ленца закон . ''Большая советская энциклопедия'', 3-е изд., гл. ред. А. М. Прохоров. Москва: Советская энциклопедия, 1972. Т. 8 () states that the of heating generated by an |
SPARC (tokamak)
SPARC is a tokamak under development by Commonwealth Fusion Systems (CFS) in collaboration with the Massachusetts Institute of Technology (MIT) Plasma Science and Fusion Center (PSFC). Funding has come from Eni, Breakthrough Energy Ventures, Khosla Ventures, Temasek, Equinor, Devonshire Investors, and others. SPARC plans to verify the technology and physics required to build a power plant based on the ARC fusion power plant concept. SPARC is designed to achieve this with margin in excess of breakeven and may be capable of achieving up to 140 MW of fusion power for 10 second bursts despite its relatively compact size. The project is on schedule for operation in 2025 after completing a magnet test in 2021. History The SPARC project was announced in 2018 with a planned completion in 2025. In March 2021, CFS announced that it planned to build SPARC at its campus in Devens, Massachusetts. In September 2021 the project successfully tested a prototype high-field coil, achieving a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
