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93-507: The Joint European Torus ( JET ) was a magnetically confined plasma physics experiment, located at Culham Centre for Fusion Energy in Oxfordshire , UK . Based on a tokamak design, the fusion research facility was a joint European project with the 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 began operation in 1983 and spent most of

186-666: A gain factor of Q = 0.62 and 4 megawatts steady state fusion power with Q = 0.18 for 4 seconds. In 2021, JET sustained Q = 0.33 for 5 seconds and produced 59 megajoules of energy, beating the record 21.7 megajoules released in 1997 over around 4 seconds. One of the challenges of MCF research is the development and extrapolation of plasma scenarios to power plant conditions, where good fusion performance and energy confinement must be maintained. Potential solutions to other problems such as divertor power exhaust, mitigation of transients (disruptions, runaway electrons , edge-localized modes ), handling of neutron flux , tritium breeding and

279-413: A neutron , where the energy is released in the form of the kinetic energy of the reaction products. In order to overcome the electrostatic repulsion between the nuclei, the fuel must have a temperature of hundreds of millions of degrees, at which the fuel is fully ionized and becomes a plasma . In addition, the plasma must be at a sufficient density, and the energy must remain in the reacting region for

372-567: A $ 46 million grant for eight companies across seven states to advance fusion power plant designs and research, aiming to establish the U.S. as a leader in clean fusion energy. The funding from the Milestone-Based Fusion Development Program supports the goal to demonstrate pilot-scale fusion within ten years and achieve a net-zero economy by 2050. The grant recipients will tackle scientific and technological hurdles to create viable fusion pilot plant designs in

465-514: A European fusion device to be developed. In 1975, the first proposals for the JET machine were completed. Detailed design took three years. At the end of 1977, after a long debate, Culham was chosen as the host site for the new design. Funding was approved on 1 April 1978 as the "JET Joint Undertaking" legal entity. The reactor was built at a new site next to the Culham Centre for Fusion Energy ,

558-659: A JET upgrade commenced using tritium, as part of its contribution to ITER. Immediately after the announcement of JET's closure at the IAEA conference in London, October 2023, the group "Scientists for JET" launched a petition to call for a review of the decision to close JET, with scientists fearing a research time gap and personnel loss between JET's closure and the start of ITER's operations. JET finished operations in December 2023, with decommissioning expected to last until 2040. As

651-481: A US team stated they were not seeing this issue, the Soviets examined their experiment and noted this was due to a simple instrumentation error. The Soviet team also introduced a potential solution, in the form of "Ioffe bars". These bent the plasma into a new shape that was concave at all points, avoiding the problem Teller had pointed out. This demonstrated a clear improvement in confinement. A UK team then introduced

744-721: A briefing paper from the House of Commons Library assessed the implications of leaving Euratom. In 2017, an article in The Independent questioned the availability of nuclear fuel to the UK after 2019 if the UK were to withdraw, and the need for new treaties relating to the transportation of nuclear materials. A 2017 article in the New Scientist stated that radioisotope supply for cancer treatments would also need to be considered in new treaties. UK politicians speculated that

837-445: A clean, cost-competitive, and sustainable fuel cycle for fusion power. The results suggest that a hydrogen-boron fuel mix has the potential to be used in utility-scale fusion power. TAE Technologies is focused on developing a fusion power plant by the mid-2030s that will produce clean electricity. The private U.S. nuclear fusion company Helion Energy has signed a deal with Microsoft to provide electricity in about five years, marking

930-455: A crucial role in regulating plasma purity and density. Wendelstein 7-X allows the investigation into plasma turbulence and the effectiveness of magnetic confinement and thermal insulation. The device's microwave heating system has also been improved to achieve higher energy throughput and plasma density. These advancements aim to demonstrate the suitability of stellarators for continuous fusion power generation. TAE Technologies achieved 2022

1023-547: A current into the plasma. The primary purpose of this current is to generate a poloidal field that mixes with the one supplied by the toroidal magnets to produce the twisted field inside the plasma. The current also serves the secondary purpose of ionizing the fuel and providing some heating of the plasma before other systems take over. The main source of heating in JET is provided by two systems, positive ion neutral beam injection and ion cyclotron resonance heating. The former uses small particle accelerators to shoot fuel atoms into

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1116-582: A dead end. In the 1970s, a solution was developed. By placing a baseball coil at either end of a large solenoid, the entire assembly could hold a much larger volume of plasma, and thus produce more energy. Plans began to build a large device of this "tandem mirror" design, which became the Mirror Fusion Test Facility (MFTF). Having never tried this layout before, a smaller machine, the Tandem Mirror Experiment (TMX)

1209-565: A dead end. In addition to the fuel loss problems, it was also calculated that a power-producing machine based on this system would be enormous, the better part of a thousand feet (300 meters) long. When the tokamak was introduced in 1968, interest in the stellarator vanished, and the latest design at Princeton University , the Model C, was eventually converted to the Symmetrical Tokamak . Stellarators have seen renewed interest since

1302-399: A divertor, allowing removal of waste material from the plasma. Performance was significantly improved, allowing JET to set many records in terms of confinement time, temperature and fusion triple product . In 1997, JET set the record for the closest approach to scientific breakeven. It attained Q = 0.67, producing 16 MW of fusion energy while injecting 24 MW of thermal power to heat

1395-468: A few megawatts of both sources, and then later be expanded to as much of 25 MW of neutral beams and 15 MW of cyclotron heating. JET's power requirements during the plasma pulse are around 500 MW with peak in excess of 1000 MW. Because power draw from the main grid is limited to 575 MW, two large flywheel generators were constructed to provide this necessary power. Each 775-ton flywheel can spin up to 225 rpm and store 3.75 GJ, roughly

1488-402: A field that extended only part way into the plasma, which proved to have the significant advantage of adding "shear", which suppressed turbulence in the plasma. However, as larger devices were built on this model, it was seen that plasma was escaping from the system much more rapidly than expected, much more rapidly than could be replaced. By the mid-1960s it appeared the stellarator approach was

1581-449: A figure-8. This has the effect of propagating the nuclei from the inside to outside as it orbits the device, thereby cancelling out the drift across the axis, at least if the nuclei orbit fast enough. Not long after the construction of the earliest figure-8 machines, it was noticed the same effect could be achieved in a completely circular arrangement by adding a second set of helically wound magnets on either side. This arrangement generated

1674-576: A full member of the organisation on 31 January 2020. However, under the terms of the UK–EU Trade and Cooperation Agreement , the United Kingdom participates in Euratom as an associated state following the end of the transition period on 31 December 2020. The driving force behind the creation of Euratom was France's desire to develop nuclear energy and nuclear weapons without having to rely on

1767-472: A gap of many years with no fusion research. JET has a major radius of 3 metres, and the D-shaped vacuum chamber is 2.5 metres wide and 4.2 metres high. The total plasma volume within it is 100 cubic metres, about 100 times larger than the largest machine in production when the JET design began. JET was one of the first tokamaks to be designed to use a D-shaped vacuum chamber. This was initially considered as

1860-413: A large tokamak experiment, JET was designed to study plasma behaviour in conditions and dimensions approaching those required in a fusion reactor. The principal aims of the experiment were to investigate: By the early 1960s, the fusion research community was in the doldrums. Many initially promising experimental paths had all failed to produce useful results, and the latest experiments suggested performance

1953-441: A measure of control over plasma turbulence and resultant energy leakage, long considered an unavoidable and intractable feature of plasmas. There is increased optimism that the plasma pressure above which the plasma disassembles can now be made large enough to sustain a fusion reaction rate acceptable for a power plant. Electromagnetic waves can be injected and steered to manipulate the paths of plasma particles and then to produce

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2046-502: A more practical material. HTS will enable reactor magnets to produce greater magnetic field and proportionally increase the transport processes necessary to generate energy. One of the largest material considerations is ensuring the inner wall will be able to handle the intense amounts of heat that will be generated (expected to approach 10 GW per square meter in heat flux from the plasma). Not only does this material need to survive, but it needs to withstand damage enough to avoid contaminating

2139-510: A new generation of machines combining PLT's injectors with superconducting magnets and vacuum vessels that could hold deuterium-tritium fuel instead of the test fuels containing pure deuterium or hydrogen that had been used up to that point. In 1971, the member states of the European Atomic Energy Community (Euratom) decided in favour of a robust fusion programme and provided the necessary legal framework for

2232-416: A new tokamak layout emerged, sometimes known as an "advanced tokamak". An advanced tokamak capable of reaching scientific breakeven would have to be very large and very expensive, which led to the international effort ITER . In 1991, the first experiments including tritium were made, allowing JET to run on the production fuel of a 50–50 mix of tritium and deuterium . It was also decided at this time to add

2325-410: A petition asking that JET not be closed was started, with scientists fearing a research time gap and personnel loss between JET's closure and the start of ITER's operations. Operations ceased in December, after performing 105,842 pulses, with decommissioning expected to last until 2040. The final pulses were used to operate JET outside of its design capabilities. The decommissioning and repurposing process

2418-527: A separate community to cover nuclear power . Louis Armand was put in charge of a study into the prospects of nuclear energy use in Europe; his report concluded that further nuclear development was needed to fill the deficit left by the exhaustion of coal deposits and to reduce dependence on oil producers. However, the Benelux states and Germany were also keen on creating a general single market , although it

2511-506: A significant research milestone by conducting the first-ever hydrogen-boron fusion experiments in a magnetically confined fusion plasma. The experiments were conducted in collaboration with Japan's National Institute for Fusion Science using a boron powder injection system developed by scientists and engineers of the Princeton Plasma Physics Laboratory . TAE's pursuit of hydrogen-boron fusion aims to develop

2604-463: A simpler arrangement of these magnets they called the "tennis ball", which was taken up in the US as the "baseball". Several baseball series machines were tested and showed much-improved performance. However, theoretical calculations showed that the maximum amount of energy they could produce would be about the same as the energy needed to run the magnets. As a power-producing machine, the mirror appeared to be

2697-558: A sufficient time, as specified by the Lawson criterion (triple product). The high temperature of a fusion plasma precludes the use of material vessels for direct containment. Magnetic confinement fusion attempts to use the physics of charged particle motion to contain the plasma particles by applying strong magnetic fields. Tokamaks and stellarators are the two leading MCF device candidates as of today. Investigation of using various magnetic configurations to confine fusion plasma began in

2790-424: A theoretical problem that suggested the plasma would also quickly escape sideways through the confinement fields. This would occur in any machine with convex magnetic fields, which existed in the centre of the mirror area. Existing machines were having other problems and it was not obvious whether this was occurring. In 1961, a Soviet team conclusively demonstrated this flute instability was indeed occurring, and when

2883-477: A way to improve the safety factor, but during the design, it was also noticed that this would make it much easier to build the system mechanically, as it reduced the net forces across the chamber that are trying to force the torus towards the centre of the major axis. Ideally, the magnets surrounding the chamber should be more curved at the top and bottom and less on the inside and outsides in order to support these forces, which leads to something like an oval shape that

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2976-494: A way to limit the value of Euratom and gain influence over the spread of nuclear technology. The Soviet Union launched a propaganda campaign against Euratom, as it sought to stoke fears among Europeans that the organization would enable West Germany to develop nuclear weapons. The Common Assembly proposed extending the powers of the ECSC to cover other sources of energy. However, Jean Monnet , ECSC architect and President, wanted

3069-608: Is an international organisation established by the Euratom Treaty on 25 March 1957 with the original purpose of creating a specialist market for nuclear power in Europe, by developing nuclear energy and distributing it to its member states while selling the surplus to non-member states. However, over the years its scope has been considerably increased to cover a large variety of areas associated with nuclear power and ionising radiation as diverse as safeguarding of nuclear materials , radiation protection and construction of

3162-511: Is expected to last until 2040. Immediately after the announcement of JET's closure at the IAEA conference in London, October 2023, the group "Scientists for JET" launched a petition to call for a review of the decision to close JET. The scientists are concerned that JET's end date was set assuming that ITER would be up and running by that date to continue fusion experiments, but with ITER's startup being postponed and ITER's deuterium-tritium (D-T) reactions only scheduled for 2039, that there will be

3255-522: Is the only former EC body that has not been incorporated into the EU. Since the end of World War II , sovereign European countries have entered into treaties and thereby co-operated and harmonised policies (or pooled sovereignty ) in an increasing number of areas, in the European integration project or the construction of Europe ( French : la construction européenne ). The following timeline outlines

3348-527: The MIT Plasma Science and Fusion Center in collaboration with Commonwealth Fusion Systems with the goal of producing a practical reactor design in the near future. In late 2020, a special issue of the Journal of Plasma Physics was published including seven studies speaking to a high level of confidence in the efficacy of the reactor design focusing on using simulations to validate predictions for

3441-778: The Maastricht Treaty created the European Union, which absorbed the Communities into the European Community pillar, yet Euratom still maintained a distinct legal personality. The European Constitution was intended to consolidate all previous treaties and increase democratic accountability in them. The Euratom treaty had not been amended as the other treaties had, so the European Parliament had been granted few powers over it. However,

3534-560: The Max Planck Institute for Plasma Physics in Germany has finished its first plasma campaigns and underwent upgrades, including the installation of over 8,000 graphite wall tiles and ten divertor modules to protect the vessel walls and enable longer plasma discharges. The experiments will test the optimized concept of Wendelstein 7-X as a stellarator fusion device for potential use in a power plant. The island divertor plays

3627-480: The neutrons being seen were created by new instabilities in the plasma mass. Further studies showed any such design would be beset with similar problems, and research using the z-pinch approach largely ended. An early attempt to build a magnetic confinement system was the stellarator , introduced by Lyman Spitzer in 1951. Essentially the stellarator consists of a torus that has been cut in half and then attached back together with straight "crossover" sections to form

3720-451: The pinch effect in a toroidal container. A large transformer wrapping the container was used to induce a current in the plasma inside. This current creates a magnetic field that squeezes the plasma into a thin ring, thus "pinching" it. The combination of Joule heating by the current and adiabatic heating as it pinches raises the temperature of the plasma to the required range in the tens of millions of degrees Kelvin. First built in

3813-455: The 1950s were overshadowed by the initial success of tokamaks, interests in stellarators re-emerged attributing to their inherent capability for steady-state and disruption-free operation distinct from tokamaks. The world's largest stellarator experiment, Wendelstein 7-X , began operation in 2015. The current record of fusion power generated by MCF devices is held by JET . In 1997, JET set the record of 16 megawatts of transient fusion power with

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3906-588: The 1950s. Early simple mirror and toroidal machines showed disappointing results of low confinement. After the declassification of fusion research by the United States , United Kingdom and Soviet Union in 1958, a breakthrough on toroidal devices was reported by the Kurchatov Institute in 1968, where its tokamak demonstrated a temperature of 1 kilo-electronvolts (around 11.6 million degree Kelvin) and some milliseconds of confinement time, and

3999-535: The 1970s was Trisops . (Trisops fired two theta-pinch rings towards each other.) Some more novel configurations produced in toroidal machines are the reversed field pinch and the Levitated Dipole Experiment . The US Navy has also claimed a "Plasma Compression Fusion Device" capable of TW power levels in a 2018 US patent filing: "It is a feature of the present invention to provide a plasma compression fusion device that can produce power in

4092-451: The D closely approximated. The flatter shape on the inside edge was also easier to support due to the larger, flatter surface. While exploring the stability of various plasma shapes on a computer, the team noticed that non-circular plasmas did not exactly cancel out the vertical drift that the twisted fields have originally been introduced to solve. If the plasma was displaced up or down, it would continue travelling in that direction. However,

4185-615: The EU, the UK was to leave Euratom, which provides the funding for JET. Talks on the funding after 2018, when the 5-year plan expired, commenced and a new agreement to extend JET's operation until 2019 or 2020 appeared to be largely complete. These talks were put on hold after the Brexit announcement. However, in March 2019, the UK Government and European Commission signed a contract extension for JET. This guaranteed JET operations until

4278-577: The European Union . Formal notice to withdraw from the EAEC was provided in March 2017, within the Article 50 notification letter, where the withdrawal was made explicit. Withdrawal only became effective following negotiations on the terms of the exit, which lasted two years and ten months. A report by the House of Commons Business, Energy and Industrial Strategy Committee , published in May 2017, questioned

4371-472: The European Union from 1 January 2021, makes provision for the United Kingdom's participation "as an associated country of all parts of the Euratom programme". In the history of European regulation, Article 37 of the Euratom Treaty represents pioneering legislation concerning binding transfrontier obligations with respect to environmental impact and protection of humans. The five-member Commission

4464-743: The International Fusion Reactor ITER . It is legally distinct from the European Union (EU) although it has the same membership , and is governed by many of the EU's institutions ; but it is the only remaining community organisation that is independent of the EU and therefore outside the regulatory control of the European Parliament. Since 2014, Switzerland has also participated in Euratom programmes as an associated state. The United Kingdom ceased to be

4557-487: The Soviets invited a team from the UK to independently test their machine. Their 1969 report confirmed the Soviet results, resulting in a "veritable stampede" of tokamak construction around the world. A key issue in tokamak designs was that they did not generate enough of an electric current in their plasma to provide enough heating to bring the fuel to fusion conditions. Some sort of external heating would be required. There

4650-451: The UK could stay in Euratom. In 2017, some argued that this would require – beyond the consent of the EU27 – amendment or revocation of the Article 50 letter of March 2017. The Nuclear Safeguards Act 2018 , making provision for safeguards after withdrawal from Euratom, received royal assent on 26 June 2018. The UK-EU Trade and Cooperation Agreement , outlining the UK's relationship with

4743-413: The UK in 1948, and followed by a series of increasingly large and powerful machines in the UK and US, all early machines proved subject to powerful instabilities in the plasma. Notable among them was the kink instability , which caused the pinched ring to thrash about and hit the walls of the container long before it reached the required temperatures. The concept was so simple, however, that herculean effort

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4836-548: The UK's fusion research laboratory which opened in 1965. The construction of the buildings was undertaken by Tarmac Construction , starting in 1978 with the Torus Hall. The Hall was completed in January 1982 and construction of the JET machine itself began immediately after the completion of the Torus Hall. The cost was 198.8 million European Units of Account (a predecessor of the euro) or 438 million in 2014 US dollars. JET

4929-637: The United States and/or the United Kingdom. The costs of nuclear development were also large, motivating France to share the costs with the other members of the European Coal and Steel Community (ECSC). During the negotiations to create Euratom, the United States and the United Kingdom sought to gain influence over nuclear development in Europe. The US and the UK created the European Nuclear Energy Agency (ENEA) as

5022-521: The area is receiving considerable experimental attention. However, spherical tokamaks to date have been at low toroidal field and as such are impractical for fusion neutron devices. Compact toroids, e.g. the spheromak and the Field-Reversed Configuration , attempt to combine the good confinement of closed magnetic surfaces configurations with the simplicity of machines without a central core. An early experiment of this type in

5115-429: The chamber more rapidly than around the chamber's length. This would require the pinch current to be reduced and the external stabilizing magnets to be made much stronger. In 1968 Russian research on the toroidal tokamak was first presented in public, with results that far outstripped existing efforts from any competing design, magnetic or not. Since then the majority of effort in magnetic confinement has been based on

5208-408: The coil is attempting to expand with a force of 6 MN , there is a net field towards the centre of the major axis of 20 MN, and a further twisting force because the poloidal field inside the plasma is in different directions on the top and bottom. All of these forces are borne on the external structure. Surrounding the entire assembly is the 2,600 tonne eight-limbed transformer which is used to induce

5301-558: The core plasma. Challenges such as this are being actively considered and accounted for in the models and predictive calculations used in the design process. Progress has been made in addressing the challenge of core-edge integration in future fusion reactors at the DIII-D National Fusion Facility. For a burning fusion plasma, it is crucial to maintain a plasma core hotter than the Sun's surface without damaging

5394-499: The end of 2024 regardless of Brexit situation. In December 2020, a JET upgrade commenced using tritium, as part of its contribution to ITER. On 21 December 2021, JET produced 59 megajoules using deuterium-tritium fuel while sustaining fusion during a five-second pulse, beating its previous record of 21.7 megajoules with Q = 0.33, set in 1997. In October 2023, JET set its final fusion energy record, producing 69.29 megajoules over 6 seconds from only 0.21 mg of D-T fuel. In November 2023,

5487-505: The first purpose-built spherical tokamak . This was essentially a spheromak with an inserted central rod. START produced impressive results, with β values at approximately 40% - three times that produced by standard tokamaks at the time. The concept has been scaled up to higher plasma currents and larger sizes, with the experiments NSTX (US), MAST (UK) and Globus-M (Russia) currently running. Spherical tokamaks have improved stability properties compared to conventional tokamaks and as such

5580-500: The first such agreement for fusion power. Helion's plant, expected to be online by 2028, aims to generate 50 megawatts or more of power. The company plans to use helium-3 , a rare gas as a fuel source. Kronos Fusion Energy has announced the development of an aneutronic fusion energy generator for clean and limitless power in national defense. In May 2023, the United States Department of Energy (DOE) announced

5673-421: The focus of a non-planar magnetic field generated in a solenoid with the field strength increased at either end of the tube. In order to escape the confinement area, nuclei had to enter a small annular area near each magnet. It was known that nuclei would escape through this area, but by adding and heating fuel continually it was felt this could be overcome. In 1954, Edward Teller gave a talk in which he outlined

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5766-722: The fuel, a record that endured until 2021. This was also the record for greatest fusion power produced. In 1998, JET's engineers developed a remote handling system with which, for the first time, it was possible to exchange certain components using artificial hands only. A "Remote Handling" system is, in general, an essential tool for any subsequent fusion power plant and especially for the International Thermonuclear Experimental Reactor (ITER) being developed at Saint-Paul-lès-Durance , in Provence , southern France. This Remote Handling system

5859-465: The gigawatt to terawatt range (and higher), with input power in the kilowatt to megawatt range." However, the patent has since been abandoned. All of these devices have faced considerable problems being scaled up and in their approach toward the Lawson criterion . One researcher has described the magnetic confinement problem in simple terms, likening it to squeezing a balloon – the air will always attempt to "pop out" somewhere else. Turbulence in

5952-462: The large electrical currents necessary to produce the magnetic fields to confine the plasma. These and other control capabilities have come from advances in basic understanding of plasma science in such areas as plasma turbulence, plasma macroscopic stability, and plasma wave propagation. Much of this progress has been achieved with a particular emphasis on the tokamak . SPARC is a tokamak using deuterium–tritium (DT) fuel, currently being designed at

6045-558: The legal inception of the European Union (EU)—the principal framework for this unification. The EU inherited many of its present responsibilities from the European Communities (EC), which were founded in the 1950s in the spirit of the Schuman Declaration . The United Kingdom announced its intention to withdraw from the EAEC on 26 January 2017, following on from its decision to withdraw from

6138-477: The legal necessity of leaving Euratom and called for a temporary extension of membership to allow time for new arrangements to be made. In June 2017, the European Commission's negotiations task force published a Position paper transmitted to EU27 on nuclear materials and safeguard equipment (Euratom) , titled "Essential Principles on nuclear materials and safeguard equipment". The following month,

6231-405: The next 5–10 years. The awardees include Commonwealth Fusion Systems , Focused Energy Inc., Princeton Stellarators Inc., Realta Fusion Inc., Tokamak Energy Inc., Type One Energy Group, Xcimer Energy Inc., and Zap Energy Inc. The world's major magnetic confinement fusion laboratories are: European Atomic Energy Community The European Atomic Energy Community ( EAEC or Euratom )

6324-415: 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 mix of 50–50 tritium and deuterium . It was also decided to add a divertor design to JET, which occurred between 1991 and 1993. Performance was significantly improved, and in 1997 JET set

6417-757: The nuclear field, at the time a very popular area, and would, along with the EEC, share the Common Assembly and Court of Justice of the ECSC, but not its executives. Euratom would have its own Council and Commission, with fewer powers than the High Authority of the European Coal and Steel Community . On 25 March 1957, the Treaties of Rome (the Euratom Treaty and the EEC Treaty ) were signed by

6510-496: The operation and capacity of the reactor. One study focused on modeling the magnetohydrodynamic (MHD) conditions in the reactor. The stability of this condition will define the limits of plasma pressure that can be achieved under varying magnetic field pressures. The progress made with SPARC has built off previously mentioned work on the ITER project and is aiming to utilize new technology in high-temperature superconductors (HTS) as

6603-404: The path to scientific breakeven finally appeared possible after decades of effort. Scientific breakeven is the point where the power produced by the fusion reactions is equal to the amount of power injected to heat the plasma. Once breakeven is achieved, even small improvements from that point begin to rapidly increase the amount of net energy being released. Teams around the world began planning for

6696-500: The physics of burning plasmas are being actively studied. Development of new technologies in plasma diagnostics , real-time control , plasma-facing materials , high-power microwave sources , vacuum engineering , cryogenics and superconducting magnets are essential in MCF research. A major area of research in the early years of fusion energy research was the magnetic mirror . Most early mirror devices attempted to confine plasma near

6789-617: The plasma boundary with minimal impact on the performance of high-confinement mode plasmas. This approach could be applied to larger fusion devices like ITER and contribute to core-edge integration in future fusion power plants. Recent experiments have also made progress in disruption prediction, ELM control, and material migration. The program is installing additional tools to optimize tokamak operation and exploring edge plasma and materials interactions. Major upgrades are being considered to enhance performance and flexibility for future fusion reactors. The Wendelstein 7-X stellarator at

6882-543: The plasma has proven to be a major problem, causing the plasma to escape the confinement area, and potentially touch the walls of the container. If this happens, a process known as " sputtering ", high-mass particles from the container (often steel and other metals) are mixed into the fusion fuel, lowering its temperature. In 1997, scientists at the Joint European Torus (JET) facilities in the UK produced 16 megawatts of fusion power. Scientists can now exercise

6975-425: The plasma, where collisions cause the atoms to ionize and become trapped with the rest of the fuel. These collisions deposit the kinetic energy of the accelerators into the plasma. Ion cyclotron resonance heating is essentially the plasma equivalent of a microwave oven , using radio waves to pump energy into the ions directly by matching their cyclotron frequency . JET was designed so it would initially be built with

7068-455: The reactor walls. Injecting impurities heavier than the plasma particles into the plasma and power exhaust region (the Divertor ) is crucial for cooling the plasma boundary without affecting the fusion performance. Conventional experiments used gaseous impurities, but the injection of boron, boron nitride, and lithium in powder form has also been tested. Experiments showed effective cooling of

7161-596: The reason it had gone unamended was the same reason the Constitution left it to remain separate from the rest of the EU: anti-nuclear sentiment among the European electorate, which may unnecessarily turn voters against the treaty. The Euratom treaty thus remains in force relatively unamended from its original signing. This overall timeline includes the establishment and development of Euratom, and shows that currently, it

7254-484: The record for the closest approach to scientific breakeven, reaching Q = 0.67 in 1997, producing 16 MW of fusion power while injecting 24 MW of thermal power to heat the fuel. Between 2009 and 2011, JET was shut down to rebuild many of its parts, to adopt concepts being used in the development of the ITER project in Saint-Paul-lès-Durance , in Provence , southern France. In December 2020,

7347-499: The same amount of kinetic energy as a train weighing 5,000 tons traveling at 140 kilometres per hour (87 mph). Each flywheel uses 8.8 MW to spin up and can generate 400 MW (briefly). 51°39′33″N 1°13′35″W  /  51.65917°N 1.22639°W  / 51.65917; -1.22639 Magnetic confinement fusion Fusion reactions for reactors usually combine light atomic nuclei of deuterium and tritium to form an alpha particle (Helium-4 nucleus) and

7440-480: The simulations demonstrated that the drift rate was slow enough that it could be counteracted using additional magnets and an electronic feedback system. The primary magnetic field in a tokamak is supplied by a series of magnets ringing the vacuum chamber. In JET, these are a series of 32 copper-wound magnets, each one weighing 12 tonnes. In total, they carry a current of 51 MA, and as they had to do so for periods of tens of seconds, they are water cooled. When operating,

7533-535: The six ECSC members and on 1 January 1958 they came into force. To save on resources, these separate executives created by the Rome Treaties were merged in 1965 by the Merger Treaty . The institutions of the EEC would take over responsibilities for the running of the ECSC and Euratom, with all three then becoming known as the European Communities even if each legally existed separately. In 1993,

7626-401: The tokamak principle. In the tokamak a current is periodically driven through the plasma itself, creating a field "around" the torus that combines with the toroidal field to produce a winding field in some ways similar to that in a modern stellarator, at least in that nuclei move from the inside to the outside of the device as they flow around it. In 1991, START was built at Culham , UK , as

7719-412: The turn of the millennium as they avoid several problems subsequently found in the tokamak. Newer models have been built, but these remain about two generations behind the latest tokamak designs. In the late 1950s, Soviet researchers noticed that the kink instability would be strongly suppressed if the twists in the path were strong enough that a particle travelled around the circumference of the inside of

7812-453: The vacuum vessel with tungsten and beryllium ones. In mid-May 2011, the shutdown reached its end. The first experimental campaign after the installation of the "ITER-Like Wall" started on 2 September 2011. On 14 July 2014, the European Commission signed a contract worth €283m for another 5-year extension so more advanced higher energy research can be performed at JET. Brexit threw the plans for JET in doubt. As part of its plan to leave

7905-410: The world's first deuterium-tritium experiment. This beat the US's machine, TFTR, by a full two years. Although very successful, JET and its counterpart TFTR failed to reach scientific breakeven. This was due to a variety of effects that had not been seen in previous machines operating at lower densities and pressures. Based on these results, and a number of advances in plasma shaping and divertor design,

7998-402: Was built to test this layout. TMX demonstrated a new series of problems that suggested MFTF would not reach its performance goals, and during construction MFTF was modified to MFTF-B. However, due to budget cuts, one day after the construction of MFTF was completed it was mothballed. Mirrors have seen little development since that time. The first real effort to build a control fusion reactor used

8091-566: Was confirmed by a visiting team from the Culham Laboratory using the Thomson scattering technique. Since then, tokamaks became the dominant line of research globally with large tokamaks such as JET , TFTR and JT-60 being constructed and operated. The ITER tokamak experiment under construction, which aims to demonstrate scientific breakeven , will be the world's largest MCF device. While early stellarators of low confinement in

8184-406: Was expended to address these issues. This led to the "stabilized pinch" concept, which added external magnets to "give the plasma a backbone" while it compressed. The largest such machine was the UK's ZETA reactor, completed in 1957, which appeared to successfully produce fusion. Only a few months after its public announcement in January 1958, these claims had to be retracted when it was discovered

8277-665: Was later to lead on to become RACE (Remote Applications in Challenging Environments) . In 1999, the European Fusion Development Agreement (EFDA) was established with responsibility for the future collective use of JET. In October 2009, a 15-month shutdown period was started to rebuild many parts of the JET to adopt concepts being used in the development of the ITER project in Saint-Paul-lès-Durance , in Provence , southern France. This including replacing carbon components in

8370-520: Was no shortage of ideas for this, and in the mid-1970s a series of machines were built around the world to explore these concepts. One of these, the Princeton Large Torus (PLT) demonstrated that neutral beam injection was a workable concept, using it to reach record temperatures well over the 50 million K that is the minimum needed for a practical reactor. With the PLT's success,

8463-463: Was one of only two tokamak models designed to work with a real deuterium - tritium fuel mix, the other being the US-built TFTR . Both were built with the hope of reaching scientific breakeven where the "fusion energy gain factor" or Q = 1.0. JET achieved its first plasma on 25 June 1983. It was officially opened on 9 April 1984 by Queen Elizabeth II . On 9 November 1991, JET performed

8556-535: Was opposed by France due to its protectionism , and Jean Monnet thought it too large and difficult a task. In the end, Monnet proposed the creation of separate atomic energy and economic communities to reconcile both groups. The Intergovernmental Conference on the Common Market and Euratom at the Château of Val-Duchesse in 1956 drew up the essentials of the new treaties. Euratom would foster cooperation in

8649-585: Was stalled at the Bohm diffusion limit, far below what would be needed for a practical fusion generator. In 1968, the Soviets held the periodic meeting of fusion researchers in Novosibirsk , where they introduced data from their T-3 tokamak. This represented a dramatic leap in fusion performance, at least 10 times what the best machines in the world had produced to that point. The results were so good that some dismissed them as faulty measurements. To counter this,

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