| 单词 | tokamak |
| 例句 | Eventually the device will contain plasma heated to 200 million degrees Celsius for about 100 seconds, far longer than previous large tokamaks. News at a glance: Avian flu, a gene-therapy setback, and an opera about a fraudulent researcher 2023-11-01T04:00:00Z The four-story-high machine is designed to hold a plasma heated to 200 million degrees Celsius for about 100 seconds, far longer than previous large tokamaks. First plasma fired up at world’s largest fusion reactor 2023-10-31T04:00:00Z The chosen model was tokamak, which uses magnetic fields to confine the plasma - a hot, ionised gas - inside a vessel. UK's nuclear fusion site ends experiments after 40 years 2023-10-13T04:00:00Z Dozens of privately funded companies are building variations on the tokamak and other innovative devices. Laser-fusion experiment squeezes out even more energy 2023-10-01T04:00:00Z The most promising approach involves using a huge doughnut-shaped magnetic cage called a tokamak to contain the isotopes while heating them to 100 million degrees Celsius so that they react. U.K. participation in the world’s largest fusion experiment is in doubt 2023-09-07T04:00:00Z This is why the leading design for fusion reactors, the tokamak, has a doughnut-shaped chamber. Math’s ‘Hairy Ball Theorem’ Has Surprising Implications 2023-08-18T04:00:00Z Powerful magnetic and electric fields flowing from and through the tokamak will girdle and heat the plasma cloud so that the atoms inside will collide and fuse together, releasing immense amounts of energy. World’s Largest Fusion Project Is in Big Trouble, New Documents Reveal 2023-06-15T04:00:00Z Suppressing or managing these fluctuations has been one of the key challenges for tokamak designers. What Is the Future of Fusion Energy? 2023-06-05T04:00:00Z One of the most popular is the tokamak, a device that creates a magnetic field to contain the burning plasma generated by a fusion reaction in a doughnut-shaped ‘torus’. This Pioneering Nuclear-Fusion Lab Is Gearing up to Break More Records 2023-04-28T04:00:00Z Engineers hope spherical tokamaks–shaped like a cored apple rather than a doughnut—can be built smaller and more cheaply than conventional tokamaks. U.K. participation in the world’s largest fusion experiment is in doubt 2023-09-07T04:00:00Z In a device known as a tokamak the plasma is confined by magnets that form a doughnut-like shape. The Israeli plan to fit a fusion reactor into a container 2023-04-27T04:00:00Z If so, the shape of fusion power could be very different from the giant magnetic furnaces known as tokamaks that are the focus of most current hopes, including the international megaproject called ITER. Startups try to turn laser fusion success into clean power plants 2023-02-14T05:00:00Z Small spherical tokamaks are one of the technologies that have brought fusion within the reach of private companies. What Is the Future of Fusion Energy? 2023-06-05T04:00:00Z The approaches include magnetic confinement of plasma—used by tokamaks and stellarators—and inertial confinement, used by NIF, and a hybrid of the two, among others. Nuclear Fusion Lab Achieves ‘Ignition’: What Does It Mean? 2022-12-13T05:00:00Z Many researchers believe furnacelike tokamaks are a better design for commercial power because they can sustain longer fusion “burns.” With historic explosion, a long sought fusion breakthrough 2022-12-13T05:00:00Z Most fusion efforts to date have employed doughnut-shaped reactors known as tokamaks. Major Fusion Energy Breakthrough to Be Announced by Scientists 2022-12-12T05:00:00Z But one big advantage ICF facilities have over tokamaks is that their different elements—lasers, reaction chambers, targets—can be developed and tested separately before they need to be combined. Startups try to turn laser fusion success into clean power plants 2023-02-14T05:00:00Z Soviet fusion visionary Lev Artsimovich, the “father of the tokamak,” once said that the world will have nuclear fusion when it decides it needs it. What Is the Future of Fusion Energy? 2023-06-05T04:00:00Z To make their plasma-confining magnetic fields, tokamaks and stellarators employ electromagnetic coils looping around the vessel and through the central hole. Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z In a tokamak, microwaves and particle beams heat the fuel and magnetic fields trap it. With historic explosion, a long sought fusion breakthrough 2022-12-13T05:00:00Z Soviet scientists designed a machine called a tokamak — a doughnut-shaped device that uses magnetic fields to confine plasma and heat it to the outrageously high temperatures needed for hydrogen nuclei to smash together. Nuclear fusion power inches closer to reality 2022-08-26T04:00:00Z Building a tokamak is all or nothing and extremely difficult to change once completed. Startups try to turn laser fusion success into clean power plants 2023-02-14T05:00:00Z For example, the toroidal coil used to confine the reactive particles in tokamaks is much like a solenoid bent into a circle. College Physics for AP Courses 2015-08-12T00:00:00Z This contrasts with tokamaks, which are prone to “instabilities”—the plasma bulging or wobbling in unpredictable ways—or more violent “disruptions,” often linked to interrupted plasma flow. Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z With NIF’s new success, proponents of such laser-based “inertial fusion energy” will be pushing for funding to see whether they can compete with the tokamaks. With historic explosion, a long sought fusion breakthrough 2022-12-13T05:00:00Z But D-D reactions are wildly inefficient at tokamak temperatures and instead of producing energy would consume huge amounts of electricity. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z ITER’s specific goal is to prove that a tokamak can produce 10 times more energy than is needed to generate the plasma. Bernard Bigot, head of gigantic ITER fusion project, dies 2022-05-15T04:00:00Z A tokamak is a form of experimental fusion reactor, which can change mass to energy. College Physics for AP Courses 2015-08-12T00:00:00Z W7-X has already operated for runs of 100 seconds—long by tokamak standards—but at relatively low power. Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z The first concerns loads on the structure holding up the tokamak. French nuclear regulator halts assembly of huge fusion reactor 2022-02-24T05:00:00Z Some of fusion’s fitfulness is innate to the design of doughnut-shaped tokamak reactors. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z While neutrons do produce some radioactivity in the tokamak structure, he explains, it's also their energy that we capture in "conventional" deuterium-tritium fusion. Fusion race kicked into high gear by smart tech 2022-02-09T05:00:00Z The tokamak's toroidal coil confines charged particles into a circular path with a helical twist due to the circulating ions themselves. College Physics for AP Courses 2015-08-12T00:00:00Z Is the search for fusion energy, long dominated by doughnut-shaped devices called tokamaks, about to undergo a shape shift? Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z But over its lifetime, the reactor itself becomes radioactive from the neutron bombardment, creating a complicated radiological environment for workers who enter the building when the tokamak is not in operation. French nuclear regulator halts assembly of huge fusion reactor 2022-02-24T05:00:00Z Because of the hostile radioactive environment, repairs will rely on robots or remote handling arms that can navigate the narrow access ports of a tokamak. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z The facility, also known as JET, is home to the world’s largest and most powerful operational tokamak — a donut-shaped device that is considered one promising method for performing controlled fusion. Experts hail big step forward in fusion technology in UK 2022-02-09T05:00:00Z Higher densities have been reached than with tokamaks, but with smaller confinement times. College Physics for AP Courses 2015-08-12T00:00:00Z Even more crucial for a future fusion power plant, they can theoretically just run and run, whereas tokamaks must stop periodically to reset their magnet coils. Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z A third concern is over welding the first two tokamak sections. French nuclear regulator halts assembly of huge fusion reactor 2022-02-24T05:00:00Z That means very little of the tritium in the doughnut-shaped reactor vessel, or tokamak, gets burned. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z Riccardo Betti, a fusion expert at the University of Rochester, said the achievement lay mainly in sustaining the reaction at high performance levels for five seconds, significantly longer than previously achieved in a tokamak. Experts hail big step forward in fusion technology in UK 2022-02-09T05:00:00Z Both are tokamaks: doughnut-shaped vessels wrapped in a grid of powerful magnets that hold the superhot ionized gas, or plasma, in place and prevent it from touching and melting the vessel walls. European fusion reactor sets record for sustained energy 2022-02-09T05:00:00Z Both stellarators and tokamaks create magnetic cages for gas at more than 100 million degrees Celsius, so hot it would melt any metal container. Twisty device explores alternative path to fusion 2022-09-06T04:00:00Z Although inertial-confinement fusion does not have to solve the problem of maintaining a hot, wobbly plasma inside a tokamak, it does require tremendous inputs of energy to trigger the fusion process. U.S. Project Reaches Major Milestone toward Practical Fusion Power 2022-02-02T05:00:00Z If existing tokamaks are any guide, Abdou says, time between failures is likely to be hours or days, and repairs will take months. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z Instead of firing a projectile to create the conditions for fusion, it heats the fuel to extreme temperatures and then captures the resulting plasma with powerful magnetic fields in a device known as a tokamak. Clean energy from the fastest moving objects on earth 2021-09-30T04:00:00Z But slow progress spurred researchers in the 1990s to design ITER, a giant tokamak 20 meters wide that holds 10 times as much plasma as JET. European fusion reactor sets record for sustained energy 2022-02-09T05:00:00Z The CFS design will be smaller than that of other tokamaks, such as ITER, a big reactor funded by multiple countries. Biden’s vaccine mandates, bad Facebook data, and a doctored portrait 2021-09-15T04:00:00Z And these spectacular results for burning plasma in inertial confinement “do not really translate to tokamaks” at all, Hurricane warns. U.S. Project Reaches Major Milestone toward Practical Fusion Power 2022-02-02T05:00:00Z In between pulses the magnetic field ebbs, interrupting tokamak operations—and power delivery. Fusion power may run out of fuel before it even gets started 2022-06-22T04:00:00Z A magnet alone does not a tokamak make, however. This powerful electromagnet could help make fusion energy a reality 2021-09-08T04:00:00Z One common fusion approach uses a reactor design called a tokamak, in which powerful magnetic fields are used to control charged gas - or plasma - inside a doughnut-shaped container. Mast Upgrade: UK experiment could sweep aside fusion hurdle 2021-05-25T04:00:00Z In the 1980s, for example, researchers built large tokamaks they thought would be big enough to produce excess energy. With ‘smoke ring’ technology, fusion startup marks steady progress 2021-04-08T04:00:00Z One approach is to confine it with magnetic fields into a doughnut shape inside a chamber called a tokamak. U.S. Project Reaches Major Milestone toward Practical Fusion Power 2022-02-02T05:00:00Z The U.K.-based JET is a tokamak, which uses powerful magnets to constrain a hot plasma so that atomic nuclei crash together and fuse, releasing energy. The science stories likely to make headlines in 2021 2020-12-31T05:00:00Z But he argues they would all become significantly easier to address in a high-field, compact tokamak. This powerful electromagnet could help make fusion energy a reality 2021-09-08T04:00:00Z This would allow components in future commercial tokamaks to last for much longer; greatly increasing the power plant's availability, improving its economic viability and reducing the cost of fusion electricity. Mast Upgrade: UK experiment could sweep aside fusion hurdle 2021-05-25T04:00:00Z So, after ITER, U.S. fusion researchers want to build a much smaller, cheaper power plant, leveraging recent advances such as supercomputer simulations of entire tokamaks, 3D printing, and magnet coils made of high-temperature superconductors. U.S. physicists rally around ambitious plan to build fusion power plant 2020-12-08T05:00:00Z Sparc employs the same kind of device as ITER: a tokamak, or doughnut-shaped chamber inside which the fusion reaction takes place. Compact Nuclear Fusion Reactor Is ‘Very Likely to Work,’ Studies Suggest 2020-09-29T04:00:00Z The hydrogen fuel is obtained from seawater and just a few grammes is needed but huge magnets are needed to contain the plasma in doughnut-shaped vacuum chamber known as a tokamak. World’s largest nuclear fusion project under assembly in France 2020-07-28T04:00:00Z A fusion reactor, or tokamak, aims to capture the energy released when nuclei of deuterium and tritium, the heavy isotopes of hydrogen, fuse to produce helium and energetic neutrons. This powerful electromagnet could help make fusion energy a reality 2021-09-08T04:00:00Z The base was lifted above the top floor of the tokamak building to lower inside. ‘Got my fingers crossed.’ As ITER fusion project marks milestone, chief ponders pandemic impact 2020-05-27T04:00:00Z All tokamaks, including spherical ones, suffer from a limitation, however. After decades of decline, the U.S. national fusion lab seeks a rebirth 2020-02-06T05:00:00Z Building a more compact tokamak is a risky option, says Anne White, a plasma physicist at the Massachusetts Institute of Technology in Cambridge. UK hatches plan to build world's first fusion power plant 2019-10-10T04:00:00Z Fusion experiments usually involve superheating a boiling soup of atoms known as a plasma inside a doughnut-shaped contraption called a tokamak. The Fusion Reactor Next Door 2019-05-13T04:00:00Z To do that, a tokamak relies on intense magnetic fields to trap and squeeze a super-hot ionized gas, or plasma, within a doughnut-shaped vacuum chamber. This powerful electromagnet could help make fusion energy a reality 2021-09-08T04:00:00Z ScienceInsider spoke with Bigot this week as the cryostat base still hovered over the tokamak pit on the end of a crane. ‘Got my fingers crossed.’ As ITER fusion project marks milestone, chief ponders pandemic impact 2020-05-27T04:00:00Z A traditional tokamak has the shape of a doughnut. After decades of decline, the U.S. national fusion lab seeks a rebirth 2020-02-06T05:00:00Z But for spherical tokamaks there are many unknowns, she says. UK hatches plan to build world's first fusion power plant 2019-10-10T04:00:00Z Some experiments control a super-hot ionized gas called plasma with magnetic fields inside a massive metal doughnut called a tokamak. Can AI help crack the code of fusion power? 2019-01-29T05:00:00Z However, researchers have yet to build a tokamak that yields more energy than it consumes, and they have long believed such a reactor needs to be large to reach that breakeven point. This powerful electromagnet could help make fusion energy a reality 2021-09-08T04:00:00Z But once that is done, researchers hope spherical tokamaks, or some other variation, will provide a route to commercial reactors that are smaller, simpler, and cheaper than ITER. Knighthood in hand, astrophysicist prepares to lead U.S. fusion lab 2018-06-19T04:00:00Z But he says that commercial power plants won't necessarily use tokamaks. Fusion energy pushed back beyond 2050 - BBC News 2017-07-11T04:00:00Z Inside a doughnut-shaped tokamak — the leading model for a practical fusion reactor — a plasma of hydrogen isotopes is compressed and heated to hundreds of millions of degrees so that the nuclei fuse, generating energy. Europe pauses funding for €500 million fusion research reactor 2017-07-05T04:00:00Z Most of the energy will be carried away by neutrons, which will escape the plasma and strike the walls of the tokamak, producing heat. A Dream of Clean Energy at a Very High Price 2017-03-27T04:00:00Z The MIT tokamak used copper magnets, which require use more power. MIT nuclear fusion record marks latest step towards unlimited clean energy 2016-10-17T04:00:00Z Spherical tokamaks do this by seeking to hold the plasma in the center of the device, close to the central column. Knighthood in hand, astrophysicist prepares to lead U.S. fusion lab 2018-06-19T04:00:00Z The world's largest ever tokamak, it will weigh 23,000 tonnes and is designed to generate 10 times the power that it consumes. Fusion energy pushed back beyond 2050 - BBC News 2017-07-11T04:00:00Z JET is the world’s largest tokamak—a doughnut-shaped fusion reactor like ITER. U.K.-E.U. fission could harm fusion research 2016-06-14T04:00:00Z The site here is now studded with tower cranes as crews work on the concrete structures that will support and surround the heart of the experiment, a doughnut-shaped chamber called a tokamak. A Dream of Clean Energy at a Very High Price 2017-03-27T04:00:00Z Its particular approach to fusion is to trap heavy isotopes of hydrogen in a doughnut-shaped vacuum vessel known as a tokamak and heat them up to a temperature of 150 million degrees. US advised to stick with troubled fusion project ITER 2016-05-25T04:00:00Z The device, known as a tokamak, was conceived by Soviet physicists in the 1950s and is considered fairly easy to build but extremely difficult to operate. German scientists to conduct nuclear fusion experiment 2016-02-03T05:00:00Z Meanwhile, startup companies with alternative fusion technologies are forging ahead while stellarators and spherical tokamaks are just launching or upgrading. A look ahead at 2016: What research trends will be hot—and what will not? 2015-12-30T05:00:00Z JET is also the only tokamak in the world equipped to use the fuel that will eventually power ITER: a mix of the hydrogen isotopes deuterium and tritium. U.K.-E.U. fission could harm fusion research 2016-06-14T04:00:00Z It was hailed as a breakthrough for the Max Planck Institute's stellarator - a chamber whose design differs from the tokamak fusion devices used elsewhere. German plasma success raises nuclear fusion hopes - BBC News 2015-12-11T05:00:00Z Federal research narrowed on what scientists saw as the most promising prototype — a machine called a tokamak, which uses magnets to contain and fuse a spinning, doughnut-shape cloud of hydrogen. Start-Ups Take On Challenge of Nuclear Fusion 2015-10-25T04:00:00Z Called a stellarator, the device has the same doughnut-shape as a tokamak but uses a complicated system of magnetic coils to achieve the same result. German scientists to conduct nuclear fusion experiment 2016-02-03T05:00:00Z Stellarators thus dwindled, and the tokamak became the preferred way to try to turn fusion into a practical and useful technology. Stellar work 2015-10-22T04:00:00Z Others seek to tweak the design of tokamaks, the current workhorses of the field. Nuclear proliferation 2015-10-22T04:00:00Z It’s a feat most often performed using a device called a tokamak. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z Its reactor concept, like that of Tri Alpha Energy, would yield power plants much smaller than a commercially viable tokamak, which would need to be larger than many stadiums are in order to work. Start-Ups Take On Challenge of Nuclear Fusion 2015-10-25T04:00:00Z Both methods work, but the tokamak is better at holding on to a plasma. Feature: The bizarre reactor that might save nuclear fusion 2015-10-21T04:00:00Z IN THE winter of 1968 three British physicists went to Moscow to examine a machine called a tokamak. Stellar work 2015-10-22T04:00:00Z The ITER, in contrast, holds the plasma steady with powerful magnetic fields inside a doughnut-shaped chamber known as a tokamak. Secretive fusion company makes reactor breakthrough 2015-08-24T04:00:00Z A tokamak is a big hollow metal doughnut wrapped in massively powerful electromagnetic coils. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z Now, a change of shape may turn the mainstream reactor design, known as a tokamak, into something simpler, faster, and cheaper—and bring us closer to achieving fusion energy. Top stories: Homebrewed heroin, jumping spiders, and fusion energy 2015-05-22T04:00:00Z “The aim is to make tokamaks smaller, cheaper, and faster—to reduce the eventual cost of electricity,” says Ian Chapman, head of tokamak science at the Culham Centre for Fusion Energy in Abingdon, U.K. Feature: The new shape of fusion 2015-05-21T04:00:00Z The Russians said the tokamak left the stellarator in the dust. Stellar work 2015-10-22T04:00:00Z The device, which is currently under construction at a site in St Paul-lez-Durance in southern France, will consist of a doughnut-shaped reactor called a tokamak. ITER's new chief will shake-up troubled fusion reactor 2014-11-20T05:00:00Z Their successor, the colossus of all tokamaks, is being built in a small town in France outside Marseilles. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z That meant cutting the domestic fusion program by about 20% to $233 million and closing one of three tokamak reactors in the United States. After Election 2014: FUSION RESEARCH 2014-10-24T04:00:00Z Culham is one of two labs about to give these portly tokamaks a major test. Feature: The new shape of fusion 2015-05-21T04:00:00Z There is no guarantee that it will now succeed where the tokamak failed. Stellar work 2015-10-22T04:00:00Z The world’s largest tokamak fusion reactor is currently under construction in Cadarache, France with initial operations slated to begin in 2020. The ITER Nuclear Fusion Experiment: Who Is Providing The Funding? [Infographic] 2014-10-20T04:00:00Z “The tokamak people have a very long timeline, which I don’t like,” Laberge says, “so we’d like to speed that up, and we think we can move faster.” Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z Most existing fusion devices slam together atoms using a tokamak, a magnetic device that contains the superheated plasma required for fusion to occur. Lockheed Martin says it's pursuing nuclear fusion. So are we going to have a new source of clean energy? 2014-10-15T04:00:00Z Other labs rushed to build small spherical tokamaks, some in countries not known for their fusion research, including Australia, Brazil, Egypt, Kazakhstan, Pakistan, and Turkey. Feature: The new shape of fusion 2015-05-21T04:00:00Z Sandia’s technique is one of several that fall into the middle ground between the extremes of laser fusion and the magnetically confined fusion of tokamaks. Z machine makes progress toward nuclear fusion 2014-10-10T04:00:00Z The panel recommends construction of new facilities including a linear system to simulate tokamak conditions, as well as beefing up an existing neutron irradiation source — possibly one at Oak Ridge National Laboratory in Tennessee. US plans for future of fusion research 2014-09-21T04:00:00Z Fusion research is too slow, too cautious, too focused on lavishing too much money on too few solutions and too many tokamaks. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z Conspire to build a 23,000-tonne doughnut-shaped vessel called a tokamak, that is wrapped with 80,000km of superconducting wire, all to contain the plasma magnetically and, for the first time, produce fusion energy continuously. Iterative processes 2014-09-18T04:00:00Z “NSTX-U will have really high injected power in a small plasma volume. Can you control that plasma? This is a necessary step before you could make a spherical tokamak power plant.” Feature: The new shape of fusion 2015-05-21T04:00:00Z Fusion researchers have long favoured tokamaks as the best way to contain this plasma beast. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z The most common method to do this is with powerful magnets around a container in the shape of a torus, akin to a doughnut, called a tokamak. Pressure for Results Mounts as Fusion Research Crawls Forward 2013-10-16T19:15:00.427Z Even in the early 1990s, Rostoker was skeptical of the tokamak hegemony. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z The tokamaks operate under the Department of Energy's Office of Science and cost just under $400 million to run annually. Can Fusion Energy Achieve a Breakthrough? 2013-10-15T14:45:00.413Z “The general idea of spherical tokamaks was to produce electricity on a smaller scale, and more cheaply,” Culham's Chapman says. Feature: The new shape of fusion 2015-05-21T04:00:00Z And as physicists refined the design, they improved the way that tokamaks controlled high-energy plasma. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z This will manifest in the International Thermonuclear Experimental Reactor, the world's largest tokamak, under construction in France. Pressure for Results Mounts as Fusion Research Crawls Forward 2013-10-16T19:15:00.427Z In a tokamak, the particles in the plasma move in tight spiral orbits around lines of electric current. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z It is also the only tokamak currently equipped to operate with a full fusion fuel made of an equal mixture of the hydrogen isotopes deuterium and tritium. Europe's JET Set Ponders Future of World's Largest Fusion Reactor 2013-07-03T22:33:33Z The narrow central hole in a spherical tokamak didn't leave enough room for the equipment that needs to fit there: part of each vertical magnet plus the central solenoid. Feature: The new shape of fusion 2015-05-21T04:00:00Z But from the beginning, many physicists have wondered whether tokamaks could ever be scaled up to achieve commercial power output. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z The central solenoid acts like the primary of a giant transformer, creating a magnetic field of 13 tesla which induces a 15-million-amp current of plasma around the doughnut-shaped reactor, known as a tokamak. ITER Fixes Problem With Superconductor for Giant Magnets 2013-02-04T19:05:00Z One way scientists fight this instability is by building bigger and bigger tokamaks, but bigger means more complex, and more power-hungry, and more expensive. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z In the 1990s, the interior of the tokamak was refitted with a structure known as a divertor to remove exhaust plasma and excess energy and allow for longer fusion pulses. Europe's JET Set Ponders Future of World's Largest Fusion Reactor 2013-07-03T22:33:33Z A few labs overseas converted some small devices designed for other purposes into spherical tokamaks, but the first true example was built at the Culham lab in 1990. Feature: The new shape of fusion 2015-05-21T04:00:00Z Cost, complexity and slow progress have also dogged inertial-confinement fusion, the most prominent alternative to the tokamaks' magnetic confinement. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z If lab astrophysics establishes itself as a worthy discipline, he might be able to graduate from his hand-me-down tokamak, he says. Lab astrophysics aims for the stars 2012-11-21T18:20:47.140Z Raising money was a challenge: tokamaks were eating up all the grant money, and energy startups are expensive, risky long-term bets, especially to Silicon Valley investors spoiled from flipping web startups for quick paydays. Inside the Quest for Fusion, Clean Energy’s Holy Grail 0002-11-29T05:00:00Z Nowhere is the problem more pronounced than the tokamak, the central structure that will eventually house ITER. Nuclear Fusion Project Struggles to Put the Pieces Together 2012-10-28T20:15:51.247Z Yet the doughnut-shaped vessels called tokamaks, designed to cage a superheated plasma using magnetic fields, remain the leading fusion strategy and are the basis of ITER. Feature: The new shape of fusion 2015-05-21T04:00:00Z But growing impatience with the tokamak technology has spurred the Tri Alpha team and many other physicists in the United States and Canada to pursue different options. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z Yes, you can argue details, like the hollow bore of a tokamak, but the size of the huge superconducting magnets and their heavy support structures provides no relief. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z The current favored technique is to use a reactor called a tokamak, which employs powerful electromagnets to confine the plasma inside a doughnut-shaped reactor vessel. How to Line a Thermonuclear Reactor 2012-08-16T20:51:00Z A task force of engineers is working through the tokamak building design floor-by-floor to finalize it. Nuclear Fusion Project Struggles to Put the Pieces Together 2012-10-28T20:15:51.247Z If it succeeds, spherical tokamaks could change the shape of fusion's future. Feature: The new shape of fusion 2015-05-21T04:00:00Z Such concerns have sparked some enthusiasm for the stellarator: a toroidal device that simplifies certain aspects of the tokamak but requires even more complex magnets. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z Bottom line - On the face of it, an ITER-like power system will be much more expensive than a comparable fission reactor, so I believe that tokamak fusion loses big-time on cost, independent of details. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Marmar’s facility houses one of three US tokamaks — doughnut-shaped vessels in which physicists magnetically confine hydrogen nuclei in a plasma and heat them until they fuse and liberate energy. US fusion in budget vice 2012-07-25T17:20:38.350Z The device consists of a doughnut-shaped reactor called a tokamak, wrapped in superconducting magnets that squeeze and heat a plasma of hydrogen isotopes to the point of fusion. Nuclear Fusion Project Struggles to Put the Pieces Together 2012-10-28T20:15:51.247Z They focused on the aspect ratio—the radius of the whole tokamak compared to the radius of the vacuum tube. Feature: The new shape of fusion 2015-05-21T04:00:00Z That sounds particularly appealing at a time when the world's leading fusion project, a giant tokamak named ITER, is mired in delays and cost overruns. Plasma physics: The fusion upstarts 2014-07-22T04:00:00Z Next, consider the fact that deuterium-tritium fusion inherently emits copious neutrons, which will induce significant radioactivity in adjacent tokamak structural and moderating materials. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Wurden blames ITER’s delays and ballooning costs on a premature commitment to a technology known as a tokamak, a doughnut-shaped cage within which powerful electromagnets confine a fusion plasma. Laser fusion nears crucial milestone 2012-03-07T18:20:22.413Z That machine is a donut-shaped device known as a tokamak that uses magnetic fields to trap an ionized gas or plasma and hold it at very high temperature and pressure. At DOE, Body Blows to Fusion, Nuclear Physics, and Particle Physics 2012-02-13T23:18:10Z Near a spherical tokamak's central hole, the Oak Ridge researchers predicted, particles would enjoy unusual stability. Feature: The new shape of fusion 2015-05-21T04:00:00Z A large part of China's fusion research is now focused on the tokamak, a Russian acronym meaning "toroidal magnetic chamber". Special report: In China the big nuclear question is "how soon"? 2011-05-03T04:48:38Z Accordingly, a tokamak power system will become highly radioactive as soon as it begins to operate and, over time, radiation damage will render those same materials structurally weak, requiring replacement. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z A tokamak is a doughnut shaped vessel in which the hydrogen gas is ionized, squeezed, and heated with intense magnetic fields until fusion takes place. U.K. Start-Up Aims to Cash in on Small Fusion Reactor 2011-02-17T18:33:55Z Studies of tokamaks of different sizes and configurations have always pointed to the same message: To contain a plasma and keep it hot, bigger is better. Feature: The new shape of fusion 2015-05-21T04:00:00Z Instead of corkscrewing lazily around the tube as in a conventional tokamak, the magnetic field lines wind tightly around the central column, holding particles there for extended periods before they return to the outside surface. Feature: The new shape of fusion 2015-05-21T04:00:00Z In the 1980s, a team at Oak Ridge National Laboratory in Tennessee explored how a simple shape change could affect tokamak performance. Feature: The new shape of fusion 2015-05-21T04:00:00Z Expected regulation will require all kinds of safety features, which will add further costs to tokamak power. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Also, the size and cost of conventional tokamaks means that they are usually built by government research labs. U.K. Start-Up Aims to Cash in on Small Fusion Reactor 2011-02-17T18:33:55Z The company changed direction, was renamed Tokamak Energy, and is now testing a first-generation superconducting spherical tokamak no taller than a person. Feature: The new shape of fusion 2015-05-21T04:00:00Z But one company hopes to go from a standing start to a small power-producing spherical tokamak in a decade. Feature: The new shape of fusion 2015-05-21T04:00:00Z Even among tokamaks, however, a nimbler alternative has emerged: a spherical tokamak. Feature: The new shape of fusion 2015-05-21T04:00:00Z While the character of the plasma in a tokamak power reactor will not likely represent a large energy-release safety issue, the superconducting magnets would contain a huge amount of stored energy. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Spherical tokamaks are variants on the traditional doughnut design, shaped instead like a cored apple. U.K. Start-Up Aims to Cash in on Small Fusion Reactor 2011-02-17T18:33:55Z Their calculations suggested that making the aspect ratio very low, so that the tokamak was essentially a sphere with narrow hole through the middle, could have many advantages. Feature: The new shape of fusion 2015-05-21T04:00:00Z High-temperature materials are cheaper to use but were thought to be unable to withstand the strong magnetic fields around a tokamak—until the new superconducting tape came along. Feature: The new shape of fusion 2015-05-21T04:00:00Z Like most experimental tokamaks, the two machines are not aiming to produce lots of energy, just learning how to control and confine plasma under fusionlike conditions. Feature: The new shape of fusion 2015-05-21T04:00:00Z Because an ITER-like tokamak reactor is inherently so large, such a building will be extremely expensive, further increasing the costs of something that is already too expensive. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z This will require additional heating of the plasma, which they will achieve by firing high-energy beams of neutral hydrogen into the tokamak. U.K. Start-Up Aims to Cash in on Small Fusion Reactor 2011-02-17T18:33:55Z But fusion heat will build up even faster in a spherical tokamak because of its compact size. Feature: The new shape of fusion 2015-05-21T04:00:00Z Imagine the doughnut shape of a conventional tokamak plumped up into a shape more like a cored apple. Feature: The new shape of fusion 2015-05-21T04:00:00Z Modern tokamaks remove heat by shaping the magnetic field into a kind of exhaust pipe, called a divertor, which siphons off some of the outermost layer of plasma and pipes it away. Feature: The new shape of fusion 2015-05-21T04:00:00Z Next, there's the induced radioactivity in the structure and moderator of a tokamak power reactor. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Our expertise is in neutron sources and small tokamaks. U.K. Start-Up Aims to Cash in on Small Fusion Reactor 2011-02-17T18:33:55Z Researchers know from experience that when a tokamak steps up in size or power, plasma can start misbehaving in new ways. Feature: The new shape of fusion 2015-05-21T04:00:00Z “Spherical tokamaks are the new kids on the block. But there are still important questions we're trying to get to the bottom of.” Feature: The new shape of fusion 2015-05-21T04:00:00Z In the coming months, they will attempt a 24-hour pulse—smashing the tokamak record of slightly over 5 hours. Feature: The new shape of fusion 2015-05-21T04:00:00Z Some tokamak proponents contend that structure might be made out of an exotic material that will have low induced radioactivity. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z I could go on with other downsides and showstoppers associated with tokamak fusion power, but I won't. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z It is enough to say that tokamak fusion power has what I believe are insurmountable barriers to practicability and acceptability. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z Friction generated as the plasma surges around the tokamak supplies some of the heat, but modern tokamaks also beam in microwaves and high-energy particles. Feature: The new shape of fusion 2015-05-21T04:00:00Z As a past leader of the U.S. federal fusion program, I played a significant role in establishing tokamak research to the U.S., and I had high hopes for its success. Dot Earth Blog: A fusion energy researcher gets practical. 2012-10-20T01:44:29Z |
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