Currently, controlled thermonuclear fusion is very often predicted as a replacement for classical nuclear power plants and even fossil fuels, however, despite a number of serious successes in this direction, not a single working prototype of a thermonuclear reactor has yet been demonstrated. The construction of the first international thermonuclear reactor ITER in France (the EU, Russia, China, India and the Republic of Korea are involved in the project) is still at an early stage of the project. At the same time, the American corporation Lockheed Martin and a team of researchers representing the Massachusetts Institute of Technology (MIT) are working on the development of an efficient thermonuclear reactor. It was MIT experts who announced in August 2015 about the development of a new project of a fairly compact tokamak.
Tokamak stands for toroidal chamber with magnetic coils. This is a torus-shaped facility designed to contain plasma in order to achieve the conditions necessary for the flow of controlled thermonuclear fusion. The very idea of a tokamak belongs to Soviet physicists. The proposal for the use of controlled thermonuclear fusion for industrial purposes, as well as a specific scheme using thermal insulation of a high-temperature plasma by an electric field, were first formulated by physicist O. A. Lavrentyev in his work written in the middle of 1950. Unfortunately, this work was "forgotten" until the 1970s. The very term tokamak was coined by IN Golovin, a student of Academician Kurchatov. It is the tokamak reactor that is currently being created within the framework of the international scientific project ITER.
While work on the creation of the ITER fusion reactor in France is proceeding rather slowly, American engineers from the Massachusetts Institute of Technology have come up with a proposal for a new design for a compact fusion reactor. Such reactors, they said, could be put into commercial operation in just 10 years. At the same time, thermonuclear power engineering, with its huge generated capacities and inexhaustible hydrogen fuel, has remained only a dream and a series of expensive laboratory experiments and experiments for decades. Over the years, physicists even had a joke: "The practical application of thermonuclear fusion will begin in 30 years, and this period will never change." Despite this, the Massachusetts Institute of Technology believes that the long-awaited breakthrough in energy will occur in just 10 years.
The confidence of the MIT engineers is based on the use of new superconducting materials to create a magnet that promises to be significantly smaller and more powerful than the available superconducting magnets. According to Professor Dennis White, director of the MIT Plasma and Fusion Center, the use of new commercially available superconducting materials based on rare earth barium copper oxide (REBCO) will allow scientists to develop compact and very powerful magnets. According to scientists, this will allow achieving greater power and density of the magnetic field, which is especially important for plasma confinement. Thanks to new superconducting materials, the reactor, according to American researchers, will be able to be performed much more compactly than the currently existing projects, in particular, the already mentioned ITER. According to preliminary estimates, with a power equal to that of ITER, the new fusion reactor will have half the diameter. Due to this, its construction will become cheaper and easier.
Another key feature in the new project of a thermonuclear reactor is the use of liquid blankets, which should replace traditional solid-state ones, which are the main "consumable material" in all modern tokamaks, since they take on the main neutron flux, converting it into thermal energy. It is reported that the liquid is much easier to replace than beryllium cassettes in copper cases, which are quite massive and weigh about 5 tons. It is the beryllium cassettes that will be used in the design of the international experimental thermonuclear reactor ITER. Brandon Sorbom, one of the leading researchers at MIT, who is working on the project, speaks of the high efficiency of the new reactor in the region of 3 to 1. At the same time, in his own words, the design of the rector in the future can be optimized, which, possibly, will allow achieving the ratio of the generated energy to the expended energy at the level of 6 to 1.
Superconducting materials based on REBCO will provide a stronger magnetic field, which makes it easier to control the plasma: the stronger the field, the smaller the volume of the core and plasma can be used. The result will be that a small fusion reactor can produce the same amount of energy as a modern large one. At the same time, it will be easier to build a compact unit and then operate it.
It should be understood that the efficiency of a thermonuclear reactor directly depends on the power of superconducting magnets. The new magnets can also be used on the existing structure of tokamaks, which have a donut-shaped core. In addition, a number of other innovations are possible. It is worth noting that the large experimental tokamak ITER currently under construction in France, near Marseille, worth about $ 40 billion, did not take into account the progress in the field of superconductors, otherwise this reactor could have been half the size, would have cost the creators much cheaper and would have been built faster. However, the possibility of installing new magnets on the ITER exists and this will be able to significantly increase its power in the future.
The strength of the magnetic field plays a key role in controlled thermonuclear fusion. Doubling this force 16 times at once increases the power of the fusion reaction. Unfortunately, the new REBCO superconductors are not able to double the strength of the magnetic field, but they are still able to increase the power of the fusion reaction by 10 times, which is also an excellent result. According to Professor Dennis White, a thermonuclear reactor, which will be able to supply electrical energy to about 100 thousand people, can be built within about 5 years. It's hard to believe it now, but an epoch-making breakthrough in energy that can stop the global warming process can happen relatively quickly, practically today. At the same time, MIT is confident that this time 10 years is not a joke, but a real date for the appearance of the first operational tokamaks.
