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Tokamak à Configuration Variable
The tokamak à configuration variable (TCV, literally "variable configuration tokamak") is an experimental tokamak located at the École Polytechnique Fédérale de Lausanne (EPFL) Swiss Plasma Center (SPC) in Lausanne, Switzerland. As the largest experimental facility of the Swiss Plasma Center, the TCV tokamak explores the physics of magnetic confinement fusion. It distinguishes itself from other tokamaks with its specialized plasma shaping capability, which can produce diverse plasma shapes without requiring hardware modifications. The research carried out on TCV contributes to the physics understanding for ITER and future fusion power plants such as DEMO. It is currently part of EUROfusion's Medium-Sized Tokamak (MST) programme, alongside ASDEX Upgrade, MAST Upgrade and WEST. The TCV tokamak produced its first plasma in November 1992 with full tokamak operation starting in June 1993. Characteristics Plasma shaping TCV features a highly elongated, rectangular vacuum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamak
A tokamak (; ) is a device which uses a powerful magnetic field generated by external magnets to confine plasma (physics), plasma in the shape of an axially symmetrical torus. The tokamak is one of several types of magnetic confinement fusion, magnetic confinement devices being developed to produce controlled thermonuclear fusion power. The tokamak concept is currently one of the leading candidates for a practical fusion reactor for providing minimally polluting electrical power. The proposal to use controlled thermonuclear fusion for industrial purposes and a specific scheme using thermal insulation of high-temperature plasma by an electric field was first formulated by the Soviet physicist Oleg Lavrentiev in a mid-1950 paper. In 1951, Andrei Sakharov and Igor Tamm modified the scheme by proposing a theoretical basis for a thermonuclear reactor, where the plasma would have the shape of a torus and be held by a magnetic field. The first tokamak was built in the Soviet Union ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WEST (formerly Tore Supra)
The WEST, or Tungsten (chemical symbol "W") Environment in Steady-state Tokamak, (formerly Tore Supra) is a French tokamak that originally began operating as Tore Supra after the discontinuation of TFR (Tokamak of Fontenay-aux-Roses) and of Petula (in Grenoble). The original name came from the words torus and superconductor, as ''Tore Supra'' was for a long time the only tokamak of this size with superconducting toroidal magnets, allowing the creation of a strong permanent toroidal magnetic field. After a major upgrade to install tungsten walls and a divertor, the tokamak was renamed WEST (the name alludes to EAST, another tokamak). WEST is situated at the nuclear research center of Cadarache, Bouches-du-Rhône in Provence, one of the sites of the Commissariat à l'Énergie Atomique. Tore Supra operated between 1988 and 2010. Its goal was to create long-duration plasmas. The upgrade to WEST took place between 2013 and 2016. WEST has been operating since 2016. Tore Supra lon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutral Beam Injector
Neutral or neutrality may refer to: Mathematics and natural science Biology * Neutral organisms, in ecology, those that obey the unified neutral theory of biodiversity Chemistry and physics * Neutralization (chemistry), a chemical reaction in which an acid and a base react quantitatively with each other * Neutral solution, a chemical solution which is neither acidic nor basic * Neutral particle, a particle without electrical charge Mathematics * Neutral element or identity element, in mathematics, a special element with respect to a binary operation, such that if the operation is applied to any element in a set, that element is unchanged * Neutral vector, a multivariate random variable that exhibits a particular type of statistical independence (Dirichlet distribution) Philosophy * Neutrality (philosophy), the absence of declared or intentional bias * Neutrality (psychoanalysis) * Neutral level, the physical or material traces of esthesic and poietic processes identified ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Cyclotron Current Drive
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up and down quarks. Electrons are extremely lightweight particles that orbit the positively charged nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electrons are the least tightly bound and are responsible for the formation of chemical bonds between atoms to create molecules and crystals. These valence electrons also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Cyclotron Resonance Heating
A tokamak (; ) is a device which uses a powerful magnetic field generated by external magnets to confine plasma (physics), plasma in the shape of an axially symmetrical torus. The tokamak is one of several types of magnetic confinement fusion, magnetic confinement devices being developed to produce controlled thermonuclear fusion power. The tokamak concept is currently one of the leading candidates for a practical fusion reactor for providing minimally polluting electrical power. The proposal to use controlled thermonuclear fusion for industrial purposes and a specific scheme using thermal insulation of high-temperature plasma by an electric field was first formulated by the Soviet physicist Oleg Lavrentiev in a mid-1950 paper. In 1951, Andrei Sakharov and Igor Tamm modified the scheme by proposing a theoretical basis for a thermonuclear reactor, where the plasma would have the shape of a torus and be held by a magnetic field. The first tokamak was built in the Soviet Union ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Diego
San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in the United States. San Diego is the county seat, seat of San Diego County. It is known for its mild Mediterranean climate, extensive List of beaches in San Diego County, beaches and List of parks in San Diego, parks, long association with the United States Navy, and recent emergence as a wireless, electronics, List of hospitals in San Diego, healthcare, and biotechnology development center. Historically home to the Kumeyaay people, San Diego has been referred to as the ''Birthplace of California'', as it was the first site visited and settled by Europeans on what is now the West Coast of the United States. In 1542, Juan Rodríguez Cabrillo claimed the area for Spain, forming the basis for the settlement of Alta California, 200 years later. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DIII-D Tokamak Facility
DIII-D is a tokamak that has been operated since the late 1980s by General Atomics (GA) in San Diego, California, for the United States Department of Energy. The DIII-D National Fusion Facility is part of the ongoing effort to achieve magnetically confined fusion. The mission of the DIII-D Research Program is to establish the scientific basis for the optimization of the tokamak approach to fusion energy production. DIII-D was built on the basis of the earlier Doublet III, the third in a series of machines built at GA to experiment with tokamaks having non-circular plasma cross sections. This work demonstrated that certain shapes strongly suppressed a variety of instabilities in the plasma, which led to much higher plasma pressure and performance. DIII-D is so-named because the plasma is shaped like the letter D, a shaping that is now widely used on modern designs, and has led to the class of machines known as "advanced tokamaks." Advanced tokamaks are characterized by operation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge-localized Mode
An edge-localized mode (ELM) is a plasma instability occurring in the edge region of a tokamak plasma due to periodic relaxations of the edge transport barrier in high-confinement mode. Each ELM burst is associated with expulsion of particles and energy from the confined plasma into the scrape-off layer. This phenomenon was first observed in the ASDEX tokamak in 1981. Diamagnetic effects in the model equations expand the size of the parameter space in which solutions of repeated sawteeth can be recovered compared to a resistive MHD model. An ELM can expel up to 20 percent of the reactor's energy. Issues ELM is a major challenge in magnetic fusion research with tokamaks, as these instabilities can: * Damage wall components (in particular divertor plates) by ablating them away due to their extremely high energy transfer rate (GW/m2); * Potentially couple or trigger other instabilities, such as the resistive wall mode (RWM) or the neoclassical tearing mode (NTM). Prevention a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Engineering And Design
Fusion, or synthesis, is the process of combining two or more distinct entities into a new whole. Fusion may also refer to: Science and technology Physics *Nuclear fusion, multiple atomic nuclei combining to form one or more different atomic nuclei and subatomic particles **Fusion power, power generation using controlled nuclear fusion reactions **Cold fusion, a hypothesized type of nuclear reaction that would occur at or near room temperature * Heat fusion, a welding process for joining two pieces of a thermoplastic material *Melting, or transitioning from solid to liquid form Biology and medicine * Binaural fusion, the cognitive process of combining the auditory information received by both ears * Binocular fusion, the cognitive process in binocular vision of combining the visual information received by both eyes * Cell fusion, a process in which several uninuclear cells combine to form a multinuclear cell * Gene fusion, a genetic event and molecular biology technique * Lipid b ... [...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] |
Gyrotron
High-power 140 GHz gyrotron for plasma heating in the Wendelstein 7-X fusion experiment, Germany. A gyrotron is a class of high-power linear-beam vacuum tubes that generates millimeter-wave electromagnetic waves by the cyclotron resonance of electrons in a strong magnetic field. Output frequencies range from about 20 to 527 GHz, covering wavelengths from microwave to the edge of the terahertz gap. Typical output powers range from tens of kilowatts to 1–2 megawatts. Gyrotrons can be designed for pulsed or continuous operation. The gyrotron was invented by Soviet scientists at NIRFI, based in Nizhny Novgorod, Russia. Principle The gyrotron is a type of free-electron maser that generates high-frequency electromagnetic radiation by stimulated cyclotron resonance of electrons moving through a strong magnetic field. It can produce high power at millimeter wavelengths because, as a ''fast-wave'' device, its dimensions can be much larger than the wavelength of the radiation. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Electron Wave
In plasma physics, an electromagnetic electron wave is a wave in a plasma which has a magnetic field component and in which primarily the electrons oscillate. In an unmagnetized plasma, an electromagnetic electron wave is simply a light wave modified by the plasma. In a magnetized plasma, there are two modes perpendicular to the field, the O and X modes, and two modes parallel to the field, the R and L waves. Waves in an unmagnetized plasma Langmuir Wave The Langmuir wave is a purely longitudinal wave, that is, the wave vector is in the same direction as the E-field. It is an electrostatic wave; as such, it doesn't have an oscillating magnetic field. A plasma consists of charged particles which react to electric fields, in contrast with dielectric matter. When electrons in a uniform, homogeneous plasma are perturbed from their equilibrium position, a charge separation occurs creating an electric field which acts as restoring force on the electrons. Since electrons have inertia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
