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Experimental Advanced Superconducting Tokamak
The Experimental Advanced Superconducting Tokamak (EAST), internal designation HT-7U (Hefei Tokamak 7 Upgrade), is an experimental superconducting tokamak magnetic fusion energy reactor in Hefei, China. The Hefei Institutes of Physical Science is conducting the experiment for the Chinese Academy of Sciences. It has operated since 2006. It is the first tokamak to employ superconducting toroidal and poloidal magnets. It aims for plasma pulses of up to 1,000 seconds. Since China is a member of the international ITER project, it is hoped that EAST will provide new impetus for its further development. History EAST followed China's first superconducting tokamak device, dubbed HT-7, built by the Institute of Plasma Physics in partnership with Russia in the early 1990s. The project was proposed in 1996 and approved in 1998. According to a 2003 schedule, buildings and site facilities were to be constructed by 2003. Tokamak assembly was to take place from 2003 through 2005. Const ... [...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 arrang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Fusion Engineering Test Reactor
The China Fusion Engineering Test Reactor (中国聚变工程实验堆, CFETR) is a proposed tokamak fusion reactor, which uses a magnetic field in order to confine plasma and generate energy. Presently, tokamak devices are leading candidates for the construction of a viable and practical thermonuclear fusion reactor. These reactors may be used to generate sustainable energy whilst ensuring a low environmental impact and a smaller carbon footprint than fossil fuel-based power plants. The CFETR utilises and intends to build upon pre-existing nuclear fusion research from the ITER program in order to address the gaps between ITER and the next generation thermonuclear plant and successor reactor class to ITER, the Demonstration Power Plant (DEMO). Presently, three domestic fusion test reactors are in operation in China. These include EAST in ASIPP at Hefei, HL-2A(M) at the Southwestern Institute of Physics (SWIP) at Chengdu and J-TEXT located at Huazhong University of Science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASDEX Upgrade
ASDEX Upgrade (''Axially Symmetric Divertor Experiment'') is a divertor tokamak, that went into operation at the Max-Planck-Institut für Plasmaphysik, Garching in 1991. At present, it is Germany's second largest fusion experiment after stellarator Wendelstein 7-X. Overview To make experiments under reactor-like conditions possible, essential plasma properties, particularly the plasma density and pressure and the wall load, have been adapted in ASDEX Upgrade to the conditions that will be present in a future fusion power plant. ASDEX Upgrade is, compared to other international tokamaks, a midsize tokamak experiment. It began operation in 1991 and it succeeds the ASDEX experiment, which was in operation from 1980 until 1990. One innovative feature of the ASDEX Upgrade experiment is its all-tungsten first wall; tungsten is a good choice for the first wall of a tokamak because of its very high melting point (over 3000 degrees Celsius) which enables it to stand up to the very ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Divertor
In nuclear fusion power research, a divertor is a device within a tokamak or a stellarator that allows the online removal of waste material from the plasma while the reactor is still operating. This allows control over the buildup of fusion products in the fuel, and removes impurities in the plasma that have entered into it from the vessel lining. The divertor was initially introduced during the earliest studies of fusion power systems in the 1950s. It was realized early on that successful fusion would result in heavier ions being created and left in the fuel (the so-called "fusion ash"). These impurities were responsible for the loss of heat, and caused other effects that made it more difficult to keep the reaction going. The divertor was proposed as a solution to this problem. Operating on the same principle as a mass spectrometer, the plasma passes through the divertor region where heavier ions are flung out of the fuel mass by centrifugal force, colliding with some sort of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutral Beam Injection
Neutral-beam injection (NBI) is one method used to heat plasma inside a fusion device consisting in a beam of high-energy neutral particles that can enter the magnetic confinement field. When these neutral particles are ionized by collision with the plasma particles, they are kept in the plasma by the confining magnetic field and can transfer most of their energy by further collisions with the plasma. By tangential injection in the torus, neutral beams also provide momentum to the plasma and current drive, one essential feature for long pulses of burning plasmas. Neutral-beam injection is a flexible and reliable technique, which has been the main heating system on a large variety of fusion devices. To date, all NBI systems were based on positive precursor ion beams. In the 1990s there has been impressive progress in negative ion sources and accelerators with the construction of multi-megawatt negative-ion-based NBI systems at LHD (H0, 180 keV) and JT-60U (D0, 500 keV). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Cyclotron Resonance Heating
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Hybrid Current Drive
Alcator C-Mod was a tokamak (a type of magnetically confined fusion device) that operated between 1991 and 2016 at the Massachusetts Institute of Technology (MIT) Plasma Science and Fusion Center (PSFC). Notable for its high toroidal magnetic field (of up to 8 Tesla), Alcator C-Mod holds the world record for volume averaged plasma pressure in a magnetically confined fusion device. Until its shutdown in 2016, it was one of the major fusion research facilities in the United States. Alcator C-Mod was the third of the Alcator (''Alto Campo Toro'', High Field Torus) tokamak series, following Alcator A (1973–1979) and Alcator C (1978–1987). It was the largest fusion reactor operated by any university and was an integral part of the larger Plasma Science and Fusion Center. History Alcator A In the late 1960s, magnetic-confinement fusion research at MIT was carried out on small-scale "table-top" experiments at the Research Laboratory for Electronics and the Francis Bitte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Cyclotron Resonance Heating
Ion cyclotron resonance is a phenomenon related to the movement of ions in a magnetic field. It is used for accelerating ions in a cyclotron, and for measuring the masses of an ionized analyte in mass spectrometry, particularly with Fourier transform ion cyclotron resonance mass spectrometers. It can also be used to follow the kinetics of chemical reactions in a dilute gas mixture, provided these involve charged species. Definition of the resonant frequency An ion in a static and uniform magnetic field will move in a circle due to the Lorentz force. The angular frequency of this ''cyclotron motion'' for a given magnetic field strength ''B'' is given by :\omega = 2\pi f = \frac, where ''z'' is the number of positive or negative charges of the ion, ''e'' is the elementary charge and ''m'' is the mass of the ion. An electric excitation signal having a frequency ''f'' will therefore resonate with ions having a mass-to-charge ratio ''m/z'' given by :\frac = \frac. The circular mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangularity (plasma Physics)
Magnetically confined fusion plasmas such as those generated in tokamaks and stellarators are characterized by a typical shape. Plasma shaping is the study of the plasma shape in such devices, and is particularly important for next step fusion devices such as ITER. This shape is conditioning partly the performance of the plasma. Tokamaks, in particular, are axisymmetric devices, and therefore one can completely define the shape of the plasma by its cross-section. History Early fusion reactor designs tended to have circular cross-sections simply because they were easy to design and understand. Generally, fusion machines using a toroidal layout, like the tokamak and most stellarators, arrange their magnetic fields so the ions and electrons in the plasma travel around the torus at high velocities. However, as the circumference of a path on the outside of the plasma area is longer than one on the inside, this caused several effects that disrupted the stability of the plasma. Du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elongation (plasma Physics)
Magnetically confined fusion plasmas such as those generated in tokamaks and stellarators are characterized by a typical shape. Plasma shaping is the study of the plasma shape in such devices, and is particularly important for next step fusion devices such as ITER. This shape is conditioning partly the performance of the plasma. Tokamaks, in particular, are axisymmetric devices, and therefore one can completely define the shape of the plasma by its cross-section. History Early fusion reactor designs tended to have circular cross-sections simply because they were easy to design and understand. Generally, fusion machines using a toroidal layout, like the tokamak and most stellarators, arrange their magnetic fields so the ions and electrons in the plasma travel around the torus at high velocities. However, as the circumference of a path on the outside of the plasma area is longer than one on the inside, this caused several effects that disrupted the stability of the plasma. Du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toroidal Field
Toroidal describes something which resembles or relates to a torus or toroid: Mathematics *Torus *Toroid, a surface of revolution which resembles a torus *Toroidal polyhedron *Toroidal coordinates, a three-dimensional orthogonal coordinate system *Toroidal and poloidal coordinates, directions relative to a torus of reference *Toroidal graph, a graph whose vertices can be placed on a torus such that no edges cross *Toroidal grid network, where an n-dimensional grid network is connected circularly in more than one dimension Engineering *Toroidal inductors and transformers, a type of electrical device *Toroidal and poloidal, directions in magnetohydrodynamics *Toroidal engine, an internal combustion engine with pistons that rotate within a toroidal space *Toroidal CVT, a type of continuously variable transmission *Toroidal reflector, a parabolic reflector which has a different focal distance depending on the angle of the mirror Other uses * Toroidal ring model in theoretical physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
