“Lockheed Martin has begun developing a compact thermonuclear reactor... The company’s website says that the first prototype will be built within a year. If this turns out to be true, in a year we will live in a completely different world,” this is the beginning of one of “The Attic.” Three years have passed since its publication, and the world has not changed that much since then.

Today, in nuclear power plant reactors, energy is generated by the decay of heavy nuclei. In thermonuclear reactors, energy is obtained during the process of fusion of nuclei, during which nuclei of less mass than the sum of the original ones are formed, and the “residue” is lost in the form of energy. Waste from nuclear reactors is radioactive, and its safe disposal is a big headache. Fusion reactors do not have this drawback, and also use widely available fuel such as hydrogen.

They have only one big problem - industrial designs don't exist yet. The task is not easy: for thermonuclear reactions, the fuel must be compressed and heated to hundreds of millions of degrees - hotter than on the surface of the Sun (where thermonuclear reactions occur naturally). It is difficult to achieve such a high temperature, but it is possible, but such a reactor consumes more energy than it produces.

However, they still have so many potential advantages that, of course, not only Lockheed Martin is involved in development.

ITER

ITER is the largest project in this area. It involves the European Union, India, China, Korea, Russia, the USA and Japan, and the reactor itself has been built on French territory since 2007, although its history goes much deeper into the past: Reagan and Gorbachev agreed on its creation in 1985. The reactor is a toroidal chamber, a “donut”, in which the plasma is held by magnetic fields, which is why it is called a tokamak - That roidal ka measure with ma rotten To atushki. The reactor will generate energy through the fusion of hydrogen isotopes - deuterium and tritium.

It is planned that ITER will receive 10 times more energy than it consumes, but this will not happen soon. It was initially planned that the reactor would begin operating in experimental mode in 2020, but then this date was postponed to 2025. At the same time, industrial energy production will begin no earlier than 2060, and we can only expect the spread of this technology somewhere at the end of the 21st century.

Wendelstein 7-X

Wendelstein 7-X is the largest stellarator-type fusion reactor. The stellarator solves the problem that plagues tokamaks - the “spreading” of plasma from the center of the torus to its walls. What the tokamak tries to cope with due to the power of the magnetic field, the stellarator solves due to its complex shape: the magnetic field holding the plasma bends to stop the advances of charged particles.

Wendelstein 7-X, as its creators hope, will be able to operate for half an hour in 21, which will give a “ticket to life” to the idea of ​​thermonuclear stations of a similar design.

National Ignition Facility

Another type of reactor uses powerful lasers to compress and heat fuel. Alas, the largest laser installation for producing thermonuclear energy, the American NIF, was unable to produce more energy than it consumes.

Which of all these projects will really take off and which will suffer the same fate as NIF is difficult to predict. All we can do is wait, hope and follow the news: the 2020s promise to be an interesting time for nuclear energy.

“Nuclear Technologies” is one of the profiles of the NTI Olympiad for schoolchildren.

We say that we will put the sun into a box. The idea is pretty. The problem is we don't know how to make the box.

Pierre-Gilles de Gennes
French Nobel laureate

All electronic devices and machines need energy and humanity consumes a lot of it. But fossil fuels are running out, and alternative energy is not yet effective enough.
There is a method of obtaining energy that ideally suits all requirements - Thermonuclear fusion. The reaction of thermonuclear fusion (the conversion of hydrogen into helium and the release of energy) constantly occurs in the sun and this process gives the planet energy in the form of solar rays. You just need to imitate it on Earth, on a smaller scale. It is enough to provide high pressure and very high temperature (10 times higher than on the Sun) and the fusion reaction will be launched. To create such conditions, you need to build a thermonuclear reactor. It will use more abundant resources on earth, will be safer and more powerful than conventional nuclear power plants. For more than 40 years, attempts have been made to build it and experiments have been conducted. In recent years, one of the prototypes even managed to obtain more energy than was expended. The most ambitious projects in this area are presented below:

Government projects

The greatest public attention has recently been given to another thermonuclear reactor design - the Wendelstein 7-X stellarator (the stellarator is more complex in its internal structure than ITER, which is a tokamak). Having spent a little more than $1 billion, German scientists built a scaled-down demonstration model of the reactor in 9 years by 2015. If it shows good results, a larger version will be built.

France's MegaJoule Laser will be the world's most powerful laser and will attempt to advance a laser-based method of building a fusion reactor. The French installation is expected to be commissioned in 2018.

NIF (National Ignition Facility) was built in the USA over 12 years and 4 billion dollars by 2012. They expected to test the technology and then immediately build a reactor, but it turned out that, as Wikipedia reports, significant work is required if the system is ever to reach ignition. As a result, grandiose plans were canceled and scientists began to gradually improve the laser. The final challenge is to raise energy transfer efficiency from 7% to 15%. Otherwise, congressional funding for this method of achieving synthesis may cease.

At the end of 2015, construction began on a building for the world’s most powerful laser installation in Sarov. It will be more powerful than the current American and future French ones and will allow conducting experiments necessary for the construction of a “laser” version of the reactor. Completion of construction in 2020.

Located in the USA, the MagLIF fusion laser is recognized as a dark horse among methods for achieving thermonuclear fusion. This method has recently shown better than expected results, but the power still needs to be increased by a factor of 1000. The laser is currently undergoing an upgrade, and by 2018 scientists hope to receive the same amount of energy as they spent. If successful, a larger version will be built.

The Russian Nuclear Physics Institute persistently experimented with the “open trap” method, which the United States abandoned in the 90s. As a result, indicators were obtained that were considered impossible for this method. BINP scientists believe that their installation is now at the level of the German Wendelstein 7-X (Q=0.1), but cheaper. Now they are building a new installation for 3 billion rubles

The head of the Kurchatov Institute constantly reminds of plans to build a small thermonuclear reactor in Russia - Ignitor. According to the plan, it should be as effective as ITER, albeit smaller. Its construction should have started 3 years ago, but this situation is typical for large scientific projects.

At the beginning of 2016, the Chinese tokamak EAST managed to reach a temperature of 50 million degrees and maintain it for 102 seconds. Before the construction of huge reactors and lasers began, all the news about thermonuclear fusion was like this. One might think that this is just a competition among scientists to see who can hold the increasingly higher temperature longer. The higher the plasma temperature and the longer it can be maintained, the closer we are to the beginning of the fusion reaction. There are dozens of such installations in the world, several more () () are being built, so the EAST record will soon be broken. In essence, these small reactors are just testing equipment before being sent to ITER.

Lockheed Martin announced a fusion energy breakthrough in 2015 that would allow them to build a small and mobile fusion reactor within 10 years. Given that even very large and not at all mobile commercial reactors were not expected until 2040, the corporation's announcement was met with skepticism. But the company has a lot of resources, so who knows. A prototype is expected in 2020.

Popular Silicon Valley startup Helion Energy has its own unique plan to achieve thermonuclear fusion. The company has raised more than $10 million and expects to create a prototype by 2019.

Low-profile startup Tri Alpha Energy has recently achieved impressive results in promoting its fusion method (theorists have developed >100 theoretical ways to achieve fusion, the tokamak is simply the simplest and most popular). The company also raised more than $100 million in investor funds.

The reactor project from the Canadian startup General Fusion is even more different from the others, but the developers are confident in it and have raised more than $100 million in 10 years to build the reactor by 2020.

The UK-based startup First light has the most accessible website, formed in 2014, and announced plans to use the latest scientific data to produce nuclear fusion at a lower cost.

Scientists from MIT wrote a paper describing a compact fusion reactor. They rely on new technologies that appeared after the construction of giant tokamaks began and promise to complete the project in 10 years. It is not yet known whether they will be given the green light to begin construction. Even if approved, an article in a magazine is an even earlier stage than a startup

Nuclear fusion is perhaps the least suitable industry for crowdfunding. But it is with his help and also with NASA funding that the Lawrenceville Plasma Physics company is going to build a prototype of its reactor. Of all the ongoing projects, this one looks the most like a scam, but who knows, maybe they will bring something useful to this grandiose work.

ITER will only be a prototype for the construction of a full-fledged DEMO installation - the first commercial fusion reactor. Its launch is now scheduled for 2044 and this is still an optimistic forecast.

But there are plans for the next stage. A hybrid thermonuclear reactor will receive energy from both atomic decay (like a conventional nuclear power plant) and fusion. In this configuration, the energy can be 10 times more, but the safety is lower. China hopes to build a prototype by 2030, but experts say that would be like trying to build hybrid cars before the invention of the internal combustion engine.

Bottom line

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Fusion power plant.

Currently, scientists are working on the creation of a thermonuclear power plant, the advantage of which is to provide humanity with electricity for an unlimited time. A thermonuclear power plant operates on the basis of thermonuclear fusion - the reaction of synthesis of heavy hydrogen isotopes with the formation of helium and the release of energy. The thermonuclear fusion reaction does not produce gaseous or liquid radioactive waste and does not produce plutonium, which is used to produce nuclear weapons. If we also take into account that the fuel for thermonuclear stations will be the heavy hydrogen isotope deuterium, which is obtained from simple water - half a liter of water contains fusion energy equivalent to that obtained by burning a barrel of gasoline - then the advantages of power plants based on thermonuclear reactions become obvious .

During a thermonuclear reaction, energy is released when light atoms combine and transform into heavier ones. To achieve this, it is necessary to heat the gas to a temperature of over 100 million degrees - much higher than the temperature at the center of the Sun.

Gas at this temperature turns into plasma. At the same time, atoms of hydrogen isotopes merge, turning into helium atoms and neutrons and releasing a large amount of energy. A commercial power plant operating on this principle would use the energy of neutrons moderated by a layer of dense material (lithium).

Compared to a nuclear power plant, a fusion reactor will leave behind much less radioactive waste.

International thermonuclear reactor ITER

Participants in the international consortium to create the world's first thermonuclear reactor, ITER, signed an agreement in Brussels that launches the practical implementation of the project.

Representatives of the European Union, the United States, Japan, China, South Korea and Russia intend to begin construction of the experimental reactor in 2007 and complete it within eight years. If everything goes according to plan, then by 2040 a demonstration power plant operating on the new principle could be built.

I would like to believe that the era of environmentally hazardous hydroelectric and nuclear power plants will soon end, and the time will come for a new power plant - a thermonuclear one, the project of which is already being implemented. But, despite the fact that the ITER (International Thermonuclear Reactor) project is almost ready; Despite the fact that already at the first operating experimental thermonuclear reactors a power exceeding 10 MW was obtained - the level of the first nuclear power plants, the first thermonuclear power plant will not start working earlier than in twenty years, because its cost is very high. The cost of the work is estimated at 10 billion euros - this is the most expensive international power plant project. Half of the costs of constructing the reactor are covered by the European Union. Other consortium participants will allocate 10% of the estimate.

Now the plan for the construction of the reactor, which will become the most expensive joint scientific project ever, must be ratified by parliamentarians of the consortium member countries.

The reactor will be built in the southern French province of Provence, in the vicinity of the city of Cadarache, where the French nuclear research center is located.

How did it all start? The “energy challenge” arose as a result of a combination of the following three factors:

1. Humanity now consumes a huge amount of energy.

Currently, the world's energy consumption is about 15.7 terawatts (TW). Dividing this value by the world population, we get approximately 2400 watts per person, which can be easily estimated and visualized. The energy consumed by every inhabitant of the Earth (including children) corresponds to the round-the-clock operation of 24 hundred-watt electric lamps. However, the consumption of this energy across the planet is very uneven, as it is very large in several countries and negligible in others. Consumption (in terms of one person) is equal to 10.3 kW in the USA (one of the record values), 6.3 kW in the Russian Federation, 5.1 kW in the UK, etc., but, on the other hand, it is equal only 0.21 kW in Bangladesh (only 2% of US energy consumption!).

2. World energy consumption is increasing dramatically.

According to the International Energy Agency (2006), global energy consumption is expected to increase by 50% by 2030. Developed countries could, of course, do just fine without additional energy, but this growth is necessary to lift people out of poverty in developing countries, where 1.5 billion people suffer from severe power shortages.

3. Currently, 80% of the world's energy comes from burning fossil fuels (oil, coal and gas), the use of which:
a) potentially poses a risk of catastrophic environmental changes;
b) inevitably must end someday.

From what has been said, it is clear that now we must prepare for the end of the era of using fossil fuels

Currently, nuclear power plants produce energy released during fission reactions of atomic nuclei on a large scale. The creation and development of such stations should be encouraged in every possible way, but it must be taken into account that the reserves of one of the most important materials for their operation (cheap uranium) can also be completely used up within the next 50 years. The possibilities of nuclear fission-based energy can (and should) be significantly expanded through the use of more efficient energy cycles, allowing the amount of energy produced to almost double. To develop energy in this direction, it is necessary to create thorium reactors (the so-called thorium breeder reactors or breeder reactors), in which the reaction produces more thorium than the original uranium, as a result of which the total amount of energy produced for a given amount of substance increases by 40 times . It also seems promising to create plutonium breeders using fast neutrons, which are much more efficient than uranium reactors and can produce 60 times more energy. It may be that to develop these areas it will be necessary to develop new, non-standard methods for obtaining uranium (for example, from sea water, which seems to be the most accessible).

Fusion power plants

The figure shows a schematic diagram (not to scale) of the device and operating principle of a thermonuclear power plant. In the central part there is a toroidal (donut-shaped) chamber with a volume of ~2000 m3, filled with tritium-deuterium (T-D) plasma heated to a temperature above 100 M°C. The neutrons produced during the fusion reaction (1) leave the “magnetic bottle” and enter the shell shown in the figure with a thickness of about 1 m.

Inside the shell, neutrons collide with lithium atoms, resulting in a reaction that produces tritium:

neutron + lithium → helium + tritium

In addition, competing reactions occur in the system (without the formation of tritium), as well as many reactions with the release of additional neutrons, which then also lead to the formation of tritium (in this case, the release of additional neutrons can be significantly enhanced, for example, by introducing beryllium atoms into the shell and lead). The general conclusion is that this facility could (at least theoretically) undergo a nuclear fusion reaction that would produce tritium. In this case, the amount of tritium produced should not only meet the needs of the installation itself, but also be even somewhat larger, which will make it possible to supply new installations with tritium. It is this operating concept that must be tested and implemented in the ITER reactor described below.

In addition, neutrons must heat the shell in so-called pilot plants (in which relatively “ordinary” construction materials will be used) to approximately 400°C. In the future, it is planned to create improved installations with a shell heating temperature above 1000°C, which can be achieved through the use of the latest high-strength materials (such as silicon carbide composites). The heat generated in the shell, as in conventional stations, is taken by the primary cooling circuit with a coolant (containing, for example, water or helium) and transferred to the secondary circuit, where water steam is produced and supplied to the turbines.

1985 - The Soviet Union proposed the next generation Tokamak plant, using the experience of four leading countries in creating fusion reactors. The United States of America, together with Japan and the European Community, put forward a proposal for the implementation of the project.

Currently, in France, construction is underway on the international experimental thermonuclear reactor ITER (International Tokamak Experimental Reactor), described below, which will be the first tokamak capable of “igniting” plasma.

The most advanced existing tokamak installations have long achieved temperatures of about 150 M°C, close to the values ​​​​required for the operation of a fusion station, but the ITER reactor should be the first large-scale power plant designed for long-term operation. In the future, it will be necessary to significantly improve its operating parameters, which will require, first of all, increasing the pressure in the plasma, since the rate of nuclear fusion at a given temperature is proportional to the square of the pressure. The main scientific problem in this case is related to the fact that when the pressure in the plasma increases, very complex and dangerous instabilities arise, that is, unstable operating modes.

Why do we need this?

The main advantage of nuclear fusion is that it requires only very small amounts of substances that are very common in nature as fuel. The nuclear fusion reaction in the described installations can lead to the release of enormous amounts of energy, ten million times higher than the standard heat released during conventional chemical reactions (such as the combustion of fossil fuels). For comparison, we point out that the amount of coal required to power a thermal power plant with a capacity of 1 gigawatt (GW) is 10,000 tons per day (ten railway cars), and a fusion plant of the same power will consume only about 1 kilogram of the D+T mixture per day .

Deuterium is a stable isotope of hydrogen; In about one out of every 3,350 molecules of ordinary water, one of the hydrogen atoms is replaced by deuterium (a legacy from the Big Bang). This fact makes it easy to organize fairly cheap production of the required amount of deuterium from water. It is more difficult to obtain tritium, which is unstable (half-life is about 12 years, as a result of which its content in nature is negligible), however, as shown above, tritium will appear directly inside the thermonuclear installation during operation, due to the reaction of neutrons with lithium.

Thus, the initial fuel for a fusion reactor is lithium and water. Lithium is a common metal widely used in household appliances (cell phone batteries, etc.). The installation described above, even taking into account non-ideal efficiency, will be able to produce 200,000 kWh of electrical energy, which is equivalent to the energy contained in 70 tons of coal. The amount of lithium required for this is contained in one computer battery, and the amount of deuterium is in 45 liters of water. The above value corresponds to the current electricity consumption (calculated per person) in the EU countries over 30 years. The very fact that such an insignificant amount of lithium can ensure the generation of such an amount of electricity (without CO2 emissions and without the slightest air pollution) is a fairly serious argument for the fastest and most vigorous development of thermonuclear energy (despite all the difficulties and problems) and even without one hundred percent confidence in the success of such research.

Deuterium should last for millions of years, and reserves of easily mined lithium are sufficient to supply needs for hundreds of years. Even if lithium in rocks runs out, we can extract it from water, where it is found in concentrations high enough (100 times higher than uranium) to make mining economically feasible.

An experimental thermonuclear reactor (International thermonuclear experimental reactor) is being built near the city of Cadarache in France. The main goal of the ITER project is to implement a controlled thermonuclear fusion reaction on an industrial scale.

Per unit weight of thermonuclear fuel, about 10 million times more energy is obtained than when burning the same amount of organic fuel, and about a hundred times more than when splitting uranium nuclei in the reactors of currently operating nuclear power plants. If the calculations of scientists and designers come true, this will give humanity an inexhaustible source of energy.

Therefore, a number of countries (Russia, India, China, Korea, Kazakhstan, USA, Canada, Japan, European Union countries) joined forces in creating the International Thermonuclear Research Reactor - a prototype of new power plants.

ITER is a facility that creates conditions for the synthesis of hydrogen and tritium atoms (an isotope of hydrogen), resulting in the formation of a new atom - a helium atom. This process is accompanied by a huge burst of energy: the temperature of the plasma in which the thermonuclear reaction occurs is about 150 million degrees Celsius (for comparison, the temperature of the Sun’s core is 40 million degrees). In this case, the isotopes burn out, leaving virtually no radioactive waste.
The scheme of participation in the international project provides for the supply of reactor components and financing of its construction. In exchange for this, each of the participating countries receives full access to all technologies for creating a thermonuclear reactor and to the results of all experimental work on this reactor, which will serve as the basis for the design of serial power thermonuclear reactors.

The reactor, based on the principle of thermonuclear fusion, has no radioactive radiation and is completely safe for the environment. It can be located almost anywhere in the world, and the fuel for it is ordinary water. Construction of ITER is expected to last about ten years, after which the reactor is expected to be in use for 20 years.

Russia's interests in the Council of the International Organization for the Construction of the ITER Thermonuclear Reactor in the coming years will be represented by Corresponding Member of the Russian Academy of Sciences Mikhail Kovalchuk, Director of the Kurchatov Institute, Institute of Crystallography of the Russian Academy of Sciences and Scientific Secretary of the Presidential Council on Science, Technology and Education. Kovalchuk will temporarily replace academician Evgeniy Velikhov in this post, who was elected chairman of the ITER International Council for the next two years and does not have the right to combine this position with the duties of an official representative of a participating country.

The total cost of construction is estimated at 5 billion euros, and the same amount will be required for trial operation of the reactor. The shares of India, China, Korea, Russia, the USA and Japan each account for approximately 10 percent of the total value, 45 percent comes from the countries of the European Union. However, the European states have not yet agreed on how exactly the costs will be distributed between them. Because of this, the start of construction was postponed to April 2010. Despite the latest delay, scientists and officials involved in ITER say they will be able to complete the project by 2018.

The estimated thermonuclear power of ITER is 500 megawatts. Individual magnet parts reach a weight of 200 to 450 tons. To cool ITER, 33 thousand cubic meters of water per day will be required.

In 1998, the United States stopped funding its participation in the project. After the Republicans came to power and rolling blackouts began in California, the Bush administration announced increased investment in energy. The United States did not intend to participate in the international project and was engaged in its own thermonuclear project. In early 2002, President Bush's technology adviser John Marburger III said that the United States had changed its mind and intended to return to the project.

In terms of the number of participants, the project is comparable to another major international scientific project - the International Space Station. The cost of ITER, which previously reached 8 billion dollars, then amounted to less than 4 billion. As a result of the withdrawal of the United States from participation, it was decided to reduce the reactor power from 1.5 GW to 500 MW. Accordingly, the price of the project has also decreased.

In June 2002, the symposium “ITER Days in Moscow” was held in the Russian capital. It discussed the theoretical, practical and organizational problems of reviving the project, the success of which can change the fate of humanity and give it a new type of energy, comparable in efficiency and economy only to the energy of the Sun.

In July 2010, representatives of the countries participating in the international thermonuclear reactor project ITER approved its budget and construction schedule at an extraordinary meeting held in Cadarache, France. .

At the last extraordinary meeting, project participants approved the start date for the first experiments with plasma - 2019. Full experiments are planned for March 2027, although the project management asked technical specialists to try to optimize the process and begin experiments in 2026. The meeting participants also decided on the costs of constructing the reactor, but the amounts planned to be spent on creating the installation were not disclosed. According to information received by the editor of the ScienceNOW portal from an unnamed source, by the time experiments begin, the cost of the ITER project could reach 16 billion euros.

The meeting in Cadarache also marked the first official working day for the new project director, Japanese physicist Osamu Motojima. Before him, the project had been led since 2005 by the Japanese Kaname Ikeda, who wished to leave his post immediately after the budget and construction deadlines were approved.

The ITER fusion reactor is a joint project of the European Union, Switzerland, Japan, USA, Russia, South Korea, China and India. The idea of ​​creating ITER has been under consideration since the 80s of the last century, however, due to financial and technical difficulties, the cost of the project is constantly growing, and the construction start date is constantly being postponed. In 2009, experts expected that work on creating the reactor would begin in 2010. Later, this date was moved, and first 2018 and then 2019 were named as the launch time of the reactor.

Thermonuclear fusion reactions are reactions of fusion of nuclei of light isotopes to form a heavier nucleus, which are accompanied by a huge release of energy. In theory, fusion reactors can produce a lot of energy at low cost, but at the moment scientists spend much more energy and money to start and maintain the fusion reaction.

Thermonuclear fusion is a cheap and environmentally friendly way to produce energy. Uncontrolled thermonuclear fusion has been occurring on the Sun for billions of years - helium is formed from the heavy hydrogen isotope deuterium. This releases a colossal amount of energy. However, people on Earth have not yet learned to control such reactions.

The ITER reactor will use hydrogen isotopes as fuel. During a thermonuclear reaction, energy is released when light atoms combine into heavier ones. To achieve this, the gas must be heated to a temperature of over 100 million degrees - much higher than the temperature at the center of the Sun. Gas at this temperature turns into plasma. At the same time, atoms of hydrogen isotopes merge, turning into helium atoms with the release of a large number of neutrons. A power plant operating on this principle will use the energy of neutrons slowed down by a layer of dense material (lithium).

Why did the creation of thermonuclear installations take so long?

Why have such important and valuable installations, the benefits of which have been discussed for almost half a century, not yet been created? There are three main reasons (discussed below), the first of which can be called external or social, and the other two - internal, that is, determined by the laws and conditions of the development of thermonuclear energy itself.

1. For a long time, it was believed that the problem of the practical use of thermonuclear fusion energy did not require urgent decisions and actions, since back in the 80s of the last century, fossil fuel sources seemed inexhaustible, and environmental problems and climate change did not concern the public. In 1976, the U.S. Department of Energy's Fusion Energy Advisory Committee attempted to estimate the time frame for R&D and a demonstration fusion power plant under various research funding options. At the same time, it was discovered that the volume of annual funding for research in this direction is completely insufficient, and if the existing level of appropriations is maintained, the creation of thermonuclear installations will never be successful, since the allocated funds do not correspond even to the minimum, critical level.

2. A more serious obstacle to the development of research in this area is that a thermonuclear installation of the type under discussion cannot be created and demonstrated on a small scale. From the explanations presented below, it will become clear that thermonuclear fusion requires not only magnetic confinement of the plasma, but also sufficient heating of it. The ratio of expended and received energy increases at least in proportion to the square of the linear dimensions of the installation, as a result of which the scientific and technical capabilities and advantages of thermonuclear installations can be tested and demonstrated only at fairly large stations, such as the mentioned ITER reactor. Society was simply not ready to finance such large projects until there was sufficient confidence in success.

3. The development of thermonuclear energy has been very complex, however (despite insufficient funding and difficulties in selecting centers for the creation of JET and ITER installations), clear progress has been observed in recent years, although an operating station has not yet been created.

The modern world is facing a very serious energy challenge, which can more accurately be called an “uncertain energy crisis.” The problem is related to the fact that reserves of fossil fuels may run out in the second half of this century. Moreover, burning fossil fuels may result in the need to somehow sequester and “store” the carbon dioxide released into the atmosphere (the CCS program mentioned above) to prevent major changes in the planet’s climate.

Currently, almost all the energy consumed by humanity is created by burning fossil fuels, and the solution to the problem may be associated with the use of solar energy or nuclear energy (the creation of fast breeder reactors, etc.). The global problem caused by the growing population of developing countries and their need to improve living standards and increase the amount of energy produced cannot be solved on the basis of these approaches alone, although, of course, any attempts to develop alternative methods of energy production should be encouraged.

Strictly speaking, we have a small choice of behavioral strategies and the development of thermonuclear energy is extremely important, even despite the lack of a guarantee of success. The Financial Times newspaper (dated January 25, 2004) wrote about this:

Let's hope that there will be no major and unexpected surprises on the path to the development of thermonuclear energy. In this case, in about 30 years we will be able to supply electric current from it to energy networks for the first time, and in just over 10 years the first commercial thermonuclear power plant will begin to operate. It is possible that in the second half of this century, nuclear fusion energy will begin to replace fossil fuels and gradually begin to play an increasingly important role in providing energy to humanity on a global scale.

There is no absolute guarantee that the task of creating thermonuclear energy (as an effective and large-scale source of energy for all humanity) will be completed successfully, but the likelihood of success in this direction is quite high. Considering the enormous potential of thermonuclear stations, all costs for projects for their rapid (and even accelerated) development can be considered justified, especially since these investments look very modest against the backdrop of the monstrous global energy market ($4 trillion per year8). Meeting humanity's energy needs is a very serious problem. As fossil fuels become less available (and their use becomes undesirable), the situation is changing, and we simply cannot afford not to develop fusion energy.

To the question “When will thermonuclear energy appear?” Lev Artsimovich (a recognized pioneer and leader of research in this field) once replied that “it will be created when it becomes truly necessary for humanity”

ITER will be the first fusion reactor to produce more energy than it consumes. Scientists measure this characteristic using a simple coefficient they call "Q." If ITER achieves all its scientific goals, it will produce 10 times more energy than it consumes. The last device built, the Joint European Torus in England, is a smaller prototype fusion reactor that, in its final stages of scientific research, achieved a Q value of almost 1. This means that it produced exactly the same amount of energy as it consumed. ITER will go beyond this by demonstrating energy creation from fusion and achieving a Q value of 10. The idea is to generate 500 MW from an energy consumption of approximately 50 MW. Thus, one of the scientific goals of ITER is to prove that a Q value of 10 can be achieved.

Another scientific goal is that ITER will have a very long "burn" time - a pulse of extended duration up to one hour. ITER is a research experimental reactor that cannot produce energy continuously. When ITER starts operating, it will be on for one hour, after which it will need to be turned off. This is important because until now the standard devices we have created have been capable of having a burning time of several seconds or even tenths of a second - this is the maximum. The "Joint European Torus" reached its Q value of 1 with a burn time of approximately two seconds with a pulse length of 20 seconds. But a process that lasts a few seconds is not truly permanent. By analogy with starting a car engine: briefly turning on the engine and then turning it off is not yet real operation of the car. Only when you drive your car for half an hour will it reach a constant operating mode and demonstrate that such a car can really be driven.

That is, from a technical and scientific point of view, ITER will provide a Q value of 10 and an increased burn time.

The thermonuclear fusion program is truly international and broad in nature. People are already counting on the success of ITER and are thinking about the next step - creating a prototype of an industrial thermonuclear reactor called DEMO. To build it, ITER needs to work. We must achieve our scientific goals because this will mean that the ideas we put forward are entirely feasible. However, I agree that you should always think about what comes next. In addition, as ITER operates for 25-30 years, our knowledge will gradually deepen and expand, and we will be able to more accurately outline our next step.

Indeed, there is no debate about whether ITER should be a tokamak. Some scientists pose the question quite differently: should ITER exist? Experts in different countries, developing their own, not so large-scale thermonuclear projects, argue that such a large reactor is not needed at all.

However, their opinion should hardly be considered authoritative. Physicists who have been working with toroidal traps for several decades were involved in the creation of ITER. The design of the experimental thermonuclear reactor in Karadash was based on all the knowledge gained during experiments on dozens of predecessor tokamaks. And these results indicate that the reactor must be a tokamak, and a large one at that.

JET At the moment, the most successful tokamak can be considered JET, built by the EU in the British town of Abingdon. This is the largest tokamak-type reactor created to date, the large radius of the plasma torus is 2.96 meters. The power of the thermonuclear reaction has already reached more than 20 megawatts with a retention time of up to 10 seconds. The reactor returns about 40% of the energy put into the plasma.

It is the physics of plasma that determines the energy balance,” Igor Semenov told Infox.ru. MIPT associate professor described what energy balance is with a simple example: “We have all seen how a fire burns. In fact, it is not wood that burns there, but gas. The energy chain there is like this: the gas burns, the wood heats, the wood evaporates, the gas burns again. Therefore, if we throw water on a fire, we will abruptly take energy from the system for the phase transition of liquid water into a vapor state. The balance will become negative and the fire will go out. There is another way - we can simply take the firebrands and spread them in space. The fire will also go out. It’s the same in the thermonuclear reactor we are building. The dimensions are chosen to create an appropriate positive energy balance for this reactor. Sufficient to build a real nuclear power plant in the future, solving at this experimental stage all the problems that currently remain unresolved.”

The dimensions of the reactor were changed once. This happened at the turn of the 20th-21st centuries, when the United States withdrew from the project, and the remaining members realized that the ITER budget (by that time it was estimated at 10 billion US dollars) was too large. Physicists and engineers were required to reduce the cost of installation. And this could only be done due to size. The “redesign” of ITER was led by the French physicist Robert Aymar, who previously worked on the French Tore Supra tokamak in Karadash. The outer radius of the plasma torus has been reduced from 8.2 to 6.3 meters. However, the risks associated with the reduction in size were partly compensated for by several additional superconducting magnets, which made it possible to implement the plasma confinement mode, which was open and studied at that time.

How did it all start? The “energy challenge” arose as a result of a combination of the following three factors:

1. Humanity now consumes a huge amount of energy.

Currently, the world's energy consumption is about 15.7 terawatts (TW). Dividing this value by the world population, we get approximately 2400 watts per person, which can be easily estimated and visualized. The energy consumed by every inhabitant of the Earth (including children) corresponds to the round-the-clock operation of 24 hundred-watt electric lamps. However, the consumption of this energy across the planet is very uneven, as it is very large in several countries and negligible in others. Consumption (in terms of one person) is equal to 10.3 kW in the USA (one of the record values), 6.3 kW in the Russian Federation, 5.1 kW in the UK, etc., but, on the other hand, it is equal only 0.21 kW in Bangladesh (only 2% of US energy consumption!).

2. World energy consumption is increasing dramatically.

According to the International Energy Agency (2006), global energy consumption is expected to increase by 50% by 2030. Developed countries could, of course, do just fine without additional energy, but this growth is necessary to lift people out of poverty in developing countries, where 1.5 billion people suffer from severe power shortages.

3. Currently, 80% of the world's energy comes from burning fossil fuels(oil, coal and gas), the use of which:

a) potentially poses a risk of catastrophic environmental changes;

b) inevitably must end someday.

From what has been said, it is clear that now we must prepare for the end of the era of using fossil fuels

Currently, nuclear power plants produce energy released during fission reactions of atomic nuclei on a large scale. The creation and development of such stations should be encouraged in every possible way, but it must be taken into account that the reserves of one of the most important materials for their operation (cheap uranium) can also be completely used up within the next 50 years. The possibilities of nuclear fission-based energy can (and should) be significantly expanded through the use of more efficient energy cycles, allowing the amount of energy produced to almost double. To develop energy in this direction, it is necessary to create thorium reactors (the so-called thorium breeder reactors or breeder reactors), in which the reaction produces more thorium than the original uranium, as a result of which the total amount of energy produced for a given amount of substance increases by 40 times . It also seems promising to create plutonium breeders using fast neutrons, which are much more efficient than uranium reactors and can produce 60 times more energy. It may be that to develop these areas it will be necessary to develop new, non-standard methods for obtaining uranium (for example, from sea water, which seems to be the most accessible).

Fusion power plants

The figure shows a schematic diagram (not to scale) of the device and operating principle of a thermonuclear power plant. In the central part there is a toroidal (donut-shaped) chamber with a volume of ~2000 m3, filled with tritium-deuterium (T–D) plasma heated to a temperature above 100 M°C. The neutrons produced during the fusion reaction (1) leave the “magnetic bottle” and enter the shell shown in the figure with a thickness of about 1 m.

Inside the shell, neutrons collide with lithium atoms, resulting in a reaction that produces tritium:

neutron + lithium → helium + tritium

In addition, competing reactions occur in the system (without the formation of tritium), as well as many reactions with the release of additional neutrons, which then also lead to the formation of tritium (in this case, the release of additional neutrons can be significantly enhanced, for example, by introducing beryllium atoms into the shell and lead). The general conclusion is that this facility could (at least theoretically) undergo a nuclear fusion reaction that would produce tritium. In this case, the amount of tritium produced should not only meet the needs of the installation itself, but also be even somewhat larger, which will make it possible to supply new installations with tritium. It is this operating concept that must be tested and implemented in the ITER reactor described below.

In addition, neutrons must heat the shell in so-called pilot plants (in which relatively “ordinary” construction materials will be used) to approximately 400°C. In the future, it is planned to create improved installations with a shell heating temperature above 1000°C, which can be achieved through the use of the latest high-strength materials (such as silicon carbide composites). The heat generated in the shell, as in conventional stations, is taken by the primary cooling circuit with a coolant (containing, for example, water or helium) and transferred to the secondary circuit, where water steam is produced and supplied to the turbines.

1985 - The Soviet Union proposed the next generation Tokamak plant, using the experience of four leading countries in creating fusion reactors. The United States of America, together with Japan and the European Community, put forward a proposal for the implementation of the project.

Currently, in France, construction is underway on the international experimental thermonuclear reactor ITER (International Tokamak Experimental Reactor), described below, which will be the first tokamak capable of “igniting” plasma.

The most advanced existing tokamak installations have long achieved temperatures of about 150 M°C, close to the values ​​​​required for the operation of a fusion station, but the ITER reactor should be the first large-scale power plant designed for long-term operation. In the future, it will be necessary to significantly improve its operating parameters, which will require, first of all, increasing the pressure in the plasma, since the rate of nuclear fusion at a given temperature is proportional to the square of the pressure. The main scientific problem in this case is related to the fact that when the pressure in the plasma increases, very complex and dangerous instabilities arise, that is, unstable operating modes.

Why do we need this?

The main advantage of nuclear fusion is that it requires only very small amounts of substances that are very common in nature as fuel. The nuclear fusion reaction in the described installations can lead to the release of enormous amounts of energy, ten million times higher than the standard heat released during conventional chemical reactions (such as the combustion of fossil fuels). For comparison, we point out that the amount of coal required to power a thermal power plant with a capacity of 1 gigawatt (GW) is 10,000 tons per day (ten railway cars), and a fusion plant of the same power will consume only about 1 kilogram of the D+T mixture per day .

Deuterium is a stable isotope of hydrogen; In about one out of every 3,350 molecules of ordinary water, one of the hydrogen atoms is replaced by deuterium (a legacy from the Big Bang). This fact makes it easy to organize fairly cheap production of the required amount of deuterium from water. It is more difficult to obtain tritium, which is unstable (half-life is about 12 years, as a result of which its content in nature is negligible), however, as shown above, tritium will appear directly inside the thermonuclear installation during operation, due to the reaction of neutrons with lithium.

Thus, the initial fuel for a fusion reactor is lithium and water. Lithium is a common metal widely used in household appliances (cell phone batteries, etc.). The installation described above, even taking into account non-ideal efficiency, will be able to produce 200,000 kWh of electrical energy, which is equivalent to the energy contained in 70 tons of coal. The amount of lithium required for this is contained in one computer battery, and the amount of deuterium is in 45 liters of water. The above value corresponds to the current electricity consumption (calculated per person) in the EU countries over 30 years. The very fact that such an insignificant amount of lithium can ensure the generation of such an amount of electricity (without CO2 emissions and without the slightest air pollution) is a fairly serious argument for the fastest and most vigorous development of thermonuclear energy (despite all the difficulties and problems) and even without one hundred percent confidence in the success of such research.

Deuterium should last for millions of years, and reserves of easily mined lithium are sufficient to supply needs for hundreds of years. Even if lithium in rocks runs out, we can extract it from water, where it is found in concentrations high enough (100 times higher than uranium) to make mining economically feasible.

An experimental thermonuclear reactor (International thermonuclear experimental reactor) is being built near the city of Cadarache in France. The main goal of the ITER project is to implement a controlled thermonuclear fusion reaction on an industrial scale.

Per unit weight of thermonuclear fuel, about 10 million times more energy is obtained than when burning the same amount of organic fuel, and about a hundred times more than when splitting uranium nuclei in the reactors of currently operating nuclear power plants. If the calculations of scientists and designers come true, this will give humanity an inexhaustible source of energy.

Therefore, a number of countries (Russia, India, China, Korea, Kazakhstan, USA, Canada, Japan, European Union countries) joined forces in creating the International Thermonuclear Research Reactor - a prototype of new power plants.

ITER is a facility that creates conditions for the synthesis of hydrogen and tritium atoms (an isotope of hydrogen), resulting in the formation of a new atom - a helium atom. This process is accompanied by a huge burst of energy: the temperature of the plasma in which the thermonuclear reaction occurs is about 150 million degrees Celsius (for comparison, the temperature of the Sun’s core is 40 million degrees). In this case, the isotopes burn out, leaving virtually no radioactive waste.

The scheme of participation in the international project provides for the supply of reactor components and financing of its construction. In exchange for this, each of the participating countries receives full access to all technologies for creating a thermonuclear reactor and to the results of all experimental work on this reactor, which will serve as the basis for the design of serial power thermonuclear reactors.

The reactor, based on the principle of thermonuclear fusion, has no radioactive radiation and is completely safe for the environment. It can be located almost anywhere in the world, and the fuel for it is ordinary water. Construction of ITER is expected to last about ten years, after which the reactor is expected to be in use for 20 years.

Russia's interests in the Council of the International Organization for the Construction of the ITER Thermonuclear Reactor in the coming years will be represented by Corresponding Member of the Russian Academy of Sciences Mikhail Kovalchuk - Director of the Kurchatov Institute, Institute of Crystallography of the Russian Academy of Sciences and Scientific Secretary of the Presidential Council on Science, Technology and Education. Kovalchuk will temporarily replace academician Evgeniy Velikhov in this post, who was elected chairman of the ITER International Council for the next two years and does not have the right to combine this position with the duties of an official representative of a participating country.

The total cost of construction is estimated at 5 billion euros, and the same amount will be required for trial operation of the reactor. The shares of India, China, Korea, Russia, the USA and Japan each account for approximately 10 percent of the total value, 45 percent comes from the countries of the European Union. However, the European states have not yet agreed on how exactly the costs will be distributed between them. Because of this, the start of construction was postponed to April 2010. Despite the latest delay, scientists and officials involved in ITER say they will be able to complete the project by 2018.

The estimated thermonuclear power of ITER is 500 megawatts. Individual magnet parts reach a weight of 200 to 450 tons. To cool ITER, 33 thousand cubic meters of water per day will be required.

In 1998, the United States stopped funding its participation in the project. After the Republicans came to power and rolling blackouts began in California, the Bush administration announced increased investment in energy. The United States did not intend to participate in the international project and was engaged in its own thermonuclear project. In early 2002, President Bush's technology adviser John Marburger III said that the United States had changed its mind and intended to return to the project.

In terms of the number of participants, the project is comparable to another major international scientific project - the International Space Station. The cost of ITER, which previously reached 8 billion dollars, then amounted to less than 4 billion. As a result of the withdrawal of the United States from participation, it was decided to reduce the reactor power from 1.5 GW to 500 MW. Accordingly, the price of the project has also decreased.

In June 2002, the symposium “ITER Days in Moscow” was held in the Russian capital. It discussed the theoretical, practical and organizational problems of reviving the project, the success of which can change the fate of humanity and give it a new type of energy, comparable in efficiency and economy only to the energy of the Sun.

In July 2010, representatives of the countries participating in the international thermonuclear reactor project ITER approved its budget and construction schedule at an extraordinary meeting held in Cadarache, France. The meeting report is available here.

At the last extraordinary meeting, project participants approved the start date for the first experiments with plasma - 2019. Full experiments are planned for March 2027, although the project management asked technical specialists to try to optimize the process and begin experiments in 2026. The meeting participants also decided on the costs of constructing the reactor, but the amounts planned to be spent on creating the installation were not disclosed. According to information received by the editor of the ScienceNOW portal from an unnamed source, by the time experiments begin, the cost of the ITER project could reach 16 billion euros.

The meeting in Cadarache also marked the first official working day for the new project director, Japanese physicist Osamu Motojima. Before him, the project had been led since 2005 by the Japanese Kaname Ikeda, who wished to leave his post immediately after the budget and construction deadlines were approved.

The ITER fusion reactor is a joint project of the European Union, Switzerland, Japan, USA, Russia, South Korea, China and India. The idea of ​​creating ITER has been under consideration since the 80s of the last century, however, due to financial and technical difficulties, the cost of the project is constantly growing, and the construction start date is constantly being postponed. In 2009, experts expected that work on creating the reactor would begin in 2010. Later, this date was moved, and first 2018 and then 2019 were named as the launch time of the reactor.

Thermonuclear fusion reactions are reactions of fusion of nuclei of light isotopes to form a heavier nucleus, which are accompanied by a huge release of energy. In theory, fusion reactors can produce a lot of energy at low cost, but at the moment scientists spend much more energy and money to start and maintain the fusion reaction.

Thermonuclear fusion is a cheap and environmentally friendly way to produce energy. Uncontrolled thermonuclear fusion has been occurring on the Sun for billions of years - helium is formed from the heavy hydrogen isotope deuterium. This releases a colossal amount of energy. However, people on Earth have not yet learned to control such reactions.

The ITER reactor will use hydrogen isotopes as fuel. During a thermonuclear reaction, energy is released when light atoms combine into heavier ones. To achieve this, the gas must be heated to a temperature of over 100 million degrees - much higher than the temperature at the center of the Sun. Gas at this temperature turns into plasma. At the same time, atoms of hydrogen isotopes merge, turning into helium atoms with the release of a large number of neutrons. A power plant operating on this principle will use the energy of neutrons slowed down by a layer of dense material (lithium).

Why did the creation of thermonuclear installations take so long?

Why have such important and valuable installations, the benefits of which have been discussed for almost half a century, not yet been created? There are three main reasons (discussed below), the first of which can be called external or social, and the other two - internal, that is, determined by the laws and conditions of the development of thermonuclear energy itself.

1. For a long time, it was believed that the problem of the practical use of thermonuclear fusion energy did not require urgent decisions and actions, since back in the 80s of the last century, fossil fuel sources seemed inexhaustible, and environmental problems and climate change did not concern the public. In 1976, the U.S. Department of Energy's Fusion Energy Advisory Committee attempted to estimate the time frame for R&D and a demonstration fusion power plant under various research funding options. At the same time, it was discovered that the volume of annual funding for research in this direction is completely insufficient, and if the existing level of appropriations is maintained, the creation of thermonuclear installations will never be successful, since the allocated funds do not correspond even to the minimum, critical level.

2. A more serious obstacle to the development of research in this area is that a thermonuclear installation of the type under discussion cannot be created and demonstrated on a small scale. From the explanations presented below, it will become clear that thermonuclear fusion requires not only magnetic confinement of the plasma, but also sufficient heating of it. The ratio of expended and received energy increases at least in proportion to the square of the linear dimensions of the installation, as a result of which the scientific and technical capabilities and advantages of thermonuclear installations can be tested and demonstrated only at fairly large stations, such as the mentioned ITER reactor. Society was simply not ready to finance such large projects until there was sufficient confidence in success.

3. The development of thermonuclear energy has been very complex, however (despite insufficient funding and difficulties in selecting centers for the creation of JET and ITER installations), clear progress has been observed in recent years, although an operating station has not yet been created.

The modern world is facing a very serious energy challenge, which can more accurately be called an “uncertain energy crisis.” The problem is related to the fact that reserves of fossil fuels may run out in the second half of this century. Moreover, burning fossil fuels may result in the need to somehow sequester and “store” the carbon dioxide released into the atmosphere (the CCS program mentioned above) to prevent major changes in the planet’s climate.

Currently, almost all the energy consumed by humanity is created by burning fossil fuels, and the solution to the problem may be associated with the use of solar energy or nuclear energy (the creation of fast breeder reactors, etc.). The global problem caused by the growing population of developing countries and their need to improve living standards and increase the amount of energy produced cannot be solved on the basis of these approaches alone, although, of course, any attempts to develop alternative methods of energy production should be encouraged.

Strictly speaking, we have a small choice of behavioral strategies and the development of thermonuclear energy is extremely important, even despite the lack of a guarantee of success. The Financial Times newspaper (dated January 25, 2004) wrote about this:

“Even if the costs of the ITER project significantly exceed the original estimate, they are unlikely to reach the level of $1 billion per year. This level of expenditure should be considered a very modest price to pay for a very reasonable opportunity to create a new source of energy for all of humanity, especially given the fact that already in this century we will inevitably have to give up the habit of wasteful and reckless burning of fossil fuels.”

Let's hope that there will be no major and unexpected surprises on the path to the development of thermonuclear energy. In this case, in about 30 years we will be able to supply electric current from it to energy networks for the first time, and in just over 10 years the first commercial thermonuclear power plant will begin to operate. It is possible that in the second half of this century, nuclear fusion energy will begin to replace fossil fuels and gradually begin to play an increasingly important role in providing energy to humanity on a global scale.

There is no absolute guarantee that the task of creating thermonuclear energy (as an effective and large-scale source of energy for all humanity) will be completed successfully, but the likelihood of success in this direction is quite high. Considering the enormous potential of thermonuclear stations, all costs for projects for their rapid (and even accelerated) development can be considered justified, especially since these investments look very modest against the backdrop of the monstrous global energy market ($4 trillion per year8). Meeting humanity's energy needs is a very serious problem. As fossil fuels become less available (and their use becomes undesirable), the situation is changing, and we simply cannot afford not to develop fusion energy.

To the question “When will thermonuclear energy appear?” Lev Artsimovich (a recognized pioneer and leader of research in this field) once replied that “it will be created when it becomes truly necessary for humanity”

ITER will be the first fusion reactor to produce more energy than it consumes. Scientists measure this characteristic using a simple coefficient they call "Q." If ITER achieves all its scientific goals, it will produce 10 times more energy than it consumes. The last device built, the Joint European Torus in England, is a smaller prototype fusion reactor that, in its final stages of scientific research, achieved a Q value of almost 1. This means that it produced exactly the same amount of energy as it consumed. ITER will go beyond this by demonstrating energy creation from fusion and achieving a Q value of 10. The idea is to generate 500 MW from an energy consumption of approximately 50 MW. Thus, one of the scientific goals of ITER is to prove that a Q value of 10 can be achieved.

Another scientific goal is that ITER will have a very long "burn" time - a pulse of extended duration up to one hour. ITER is a research experimental reactor that cannot produce energy continuously. When ITER starts operating, it will be on for one hour, after which it will need to be turned off. This is important because until now the standard devices we have created have been capable of having a burning time of several seconds or even tenths of a second - this is the maximum. The "Joint European Torus" reached its Q value of 1 with a burn time of approximately two seconds with a pulse length of 20 seconds. But a process that lasts a few seconds is not truly permanent. By analogy with starting a car engine: briefly turning on the engine and then turning it off is not yet real operation of the car. Only when you drive your car for half an hour will it reach a constant operating mode and demonstrate that such a car can really be driven.

That is, from a technical and scientific point of view, ITER will provide a Q value of 10 and an increased burn time.

The thermonuclear fusion program is truly international and broad in nature. People are already counting on the success of ITER and are thinking about the next step - creating a prototype of an industrial thermonuclear reactor called DEMO. To build it, ITER needs to work. We must achieve our scientific goals because this will mean that the ideas we put forward are entirely feasible. However, I agree that you should always think about what comes next. In addition, as ITER operates for 25-30 years, our knowledge will gradually deepen and expand, and we will be able to more accurately outline our next step.

Indeed, there is no debate about whether ITER should be a tokamak. Some scientists pose the question quite differently: should ITER exist? Experts in different countries, developing their own, not so large-scale thermonuclear projects, argue that such a large reactor is not needed at all.

However, their opinion should hardly be considered authoritative. Physicists who have been working with toroidal traps for several decades were involved in the creation of ITER. The design of the experimental thermonuclear reactor in Karadash was based on all the knowledge gained during experiments on dozens of predecessor tokamaks. And these results indicate that the reactor must be a tokamak, and a large one at that.

JET At the moment, the most successful tokamak can be considered JET, built by the EU in the British town of Abingdon. This is the largest tokamak-type reactor created to date, the large radius of the plasma torus is 2.96 meters. The power of the thermonuclear reaction has already reached more than 20 megawatts with a retention time of up to 10 seconds. The reactor returns about 40% of the energy put into the plasma.

It is the physics of plasma that determines the energy balance,” Igor Semenov told Infox.ru. MIPT associate professor described what energy balance is with a simple example: “We have all seen how a fire burns. In fact, it is not wood that burns there, but gas. The energy chain there is like this: the gas burns, the wood heats, the wood evaporates, the gas burns again. Therefore, if we throw water on a fire, we will abruptly take energy from the system for the phase transition of liquid water into a vapor state. The balance will become negative and the fire will go out. There is another way - we can simply take the firebrands and spread them in space. The fire will also go out. It’s the same in the thermonuclear reactor we are building. The dimensions are chosen to create an appropriate positive energy balance for this reactor. Sufficient to build a real nuclear power plant in the future, solving at this experimental stage all the problems that currently remain unresolved.”

The dimensions of the reactor were changed once. This happened at the turn of the 20th-21st centuries, when the United States withdrew from the project, and the remaining members realized that the ITER budget (by that time it was estimated at 10 billion US dollars) was too large. Physicists and engineers were required to reduce the cost of installation. And this could only be done due to size. The “redesign” of ITER was led by the French physicist Robert Aymar, who previously worked on the French Tore Supra tokamak in Karadash. The outer radius of the plasma torus has been reduced from 8.2 to 6.3 meters. However, the risks associated with the reduction in size were partly compensated for by several additional superconducting magnets, which made it possible to implement the plasma confinement mode, which was open and studied at that time.