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JT-60
JT-60 (short for Japan Torus-60) is a large research tokamak, the flagship of Japan's magnetic fusion program, previously run by the Japan Atomic Energy Research Institute (JAERI) and currently run by the Japan Atomic Energy Agency's (JAEA) Naka Fusion Institute in Ibaraki Prefecture. It is properly an advanced tokamak, including a D-shaped plasma cross-section and active feedback control. First designed in the 1970s as the "Breakeven Plasma Test Facility" (BPTF), the goal of the system was to reach breakeven fusion power, a goal set for the US's TFTR, the UK's JET and the Soviet T-15. JT-60 began operations in 1985, and like the TFTR and JET that began operations only shortly before it, JT-60 demonstrated performance far below predictions. Over the next two decades, JET and JT-60 led the effort to regain the performance originally expected of these machines. JT-60 underwent two major modifications during this time, producing JT-60A, and then JT-60U (for "upgrade"). These cha ... [...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] |
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] |
Advanced 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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamaks
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 ... [...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 studyin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Energy Gain Factor
A fusion energy gain factor, usually expressed with the symbol ''Q'', is the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in steady state. The condition of ''Q'' = 1, when the power being released by the fusion reactions is equal to the required heating power, is referred to as breakeven, or in some sources, scientific breakeven. The energy given off by the fusion reactions may be captured within the fuel, leading to ''self-heating''. Most fusion reactions release at least some of their energy in a form that cannot be captured within the plasma, so a system at ''Q'' = 1 will cool without external heating. With typical fuels, self-heating in fusion reactors is not expected to match the external sources until at least ''Q'' ≈ 5. If ''Q'' increases past this point, increasing self-heating eventually removes the need for external heating. At this point the reaction becomes self-sustaining, a condition called combustion, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITER
ITER (initially the International Thermonuclear Experimental Reactor, ''iter'' meaning "the way" or "the path" in Latin) is an international nuclear fusion research and engineering megaproject aimed at creating energy by replicating, on Earth, the fusion processes of the Sun. Upon completion of construction of the main reactor and first plasma, planned for late 2025, it will be the world's largest magnetic confinement plasma physics experiment and the largest experimental tokamak nuclear fusion reactor. It is being built next to the Cadarache facility in southern France. ITER will be the largest of more than 100 fusion reactors built since the 1950s, with ten times the plasma volume of any other tokamak operating today. The long-term goal of fusion research is to generate electricity. ITER's stated purpose is scientific research, and technological demonstration of a large fusion reactor, without electricity generation. ITER's goals are to achieve enough fusion to produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint European Torus
The Joint European Torus, or JET, is an operational Magnetic confinement fusion, magnetically confined Plasma (physics), plasma physics experiment, located at Culham Centre for Fusion Energy in Oxfordshire, United Kingdom, UK. Based on a tokamak design, the fusion research facility is a joint European project with a main purpose of opening the way to future nuclear fusion grid energy. At the time of its design JET was larger than any comparable machine. JET was built with the hope of reaching fusion energy gain factor, ''scientific breakeven'' where the fusion energy gain factor ''Q'' =1.0. It began operation in 1983 and spent most of the next decade increasing its performance in a lengthy series of experiments and upgrades. In 1991 the first experiments including tritium were made, making JET the first reactor in the world to run on the production fuel of a 50–50 mix of tritium and deuterium. It was also decided to add a divertor, divertor design to JET, which occurred between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Triple Product
The Lawson criterion is a figure of merit used in nuclear fusion research. It compares the rate of energy being generated by fusion reactions within the fusion fuel to the rate of energy losses to the environment. When the rate of production is higher than the rate of loss, the system will produce net energy. If enough of that energy is captured by the fuel, the system will become self-sustaining and is said to be ignited. The concept was first developed by John D. Lawson in a classified 1955 paper that was declassified and published in 1957. As originally formulated, the Lawson criterion gives a minimum required value for the product of the plasma (electron) density ''n''e and the "energy confinement time" \tau_E that leads to net energy output. Later analysis suggested that a more useful figure of merit is the triple product of density, confinement time, and plasma temperature ''T''. The triple product also has a minimum required value, and the name "Lawson criterion" may r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Atomic Energy Agency
The is an Independent Administrative Institution formed on October 1, 2005 by a merger of two previous semi-governmental organizations. While it inherited the activities of both JNC and JAERI, it also inherited the nickname of JAERI, "Genken" 原研, an abbreviated word for "nuclear research". On April 10, 2007, JAEA officially joined the GNEP alliance. The other members in the alliance are Areva, Washington Group International and BWX. It is expected that the experience gained from the Rokkasho centrifuge enrichment plant will be a key contribution from JAEA. On April 1, 2016, JAEA transferred some of its laboratories to the National Institute of Radiological Sciences (NIRS), and the NIRS body was renamed to the National Institutes for Quantum and Radiological Science and Technology (QST) which includes existing laboratories of the NIRS. In 2018 JAEA estimated it would need about 1.9 trillion yen ($17.1 billion) to decommission 79 facilities over 70 years. Overview *Est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superconducting
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] |
