Problems of thermonuclear fusion control (TF). International Journal of Applied and Fundamental Research Problems of creating thermonuclear installations

A new technique has been developed to effectively slow down runaway electrons by introducing “heavy” ions, such as neon or argon, into the reactor.

A functional fusion reactor is still a dream, but it could eventually become a reality with much research and experimentation to unlock an unlimited supply of clean energy. The problems that scientists face in obtaining nuclear fusion are undoubtedly serious and truly complex, but everything can be overcome. And it seems that one of the main problems has been solved.

Nuclear fusion is not a process invented by mankind, but exists in nature from the beginning; the process powers our Sun. Deep inside our home star, hydrogen atoms are arranged together to form helium, which is the impetus for the process. Nuclear fusion releases enormous amounts of energy, but requires enormous costs to create extremely high pressure and temperature, which is difficult to replicate on Earth in a controlled manner.

Last year, researchers at MIT brought us closer to fusion by exposing plasma to just the right pressure, but now two Chalmers University researchers have uncovered another piece of the puzzle.

One of the problems that engineers have encountered is runaway electrons. These extremely high-energy electrons can suddenly and unexpectedly accelerate to very high speeds, which can destroy the reactor wall without warning.

Doctoral students Linnea Heschlow and Ole Emberose developed a new technique to effectively slow down these runaway electrons by introducing “heavy” ions such as neon or argon into the reactor. As a result, the highly charged electrons hitting the nuclei of these ions slow down and become much more manageable.

“When we can effectively slow down runaway electrons, we will be one step closer to a functional fusion reactor,” says Linnea Heschlov.

The researchers created a model that can effectively predict electron energy and behavior. Using Mathematical Modeling of Plasma, physicists can now effectively control the escape velocity of electrons without interrupting the fusion process.

“A lot of people think it will work, but it's easier to go to Mars than to achieve a merger,” says Linnea Heschlow: “You could say that we're trying to bring together stars here on earth, and that might take some time. It takes incredibly high temperatures, hotter than the center of the sun, for us to successfully achieve the merger here on earth. So I hope it’s all a matter of time.”

based on materials from newatlas.com, translation

3. Problems of controlled thermonuclear fusion

Researchers from all developed countries pin their hopes on overcoming the coming energy crisis on a controlled thermonuclear reaction. Such a reaction - the synthesis of helium from deuterium and tritium - has been taking place on the Sun for millions of years, and under terrestrial conditions they have been trying to carry it out for fifty years now in giant and very expensive laser installations, tokamaks (a device for carrying out thermonuclear fusion reactions in hot plasma) and stellarators ( closed magnetic trap for confining high-temperature plasma). However, there are other ways to solve this difficult problem, and instead of huge tokamaks, it will probably be possible to use a fairly compact and inexpensive collider - a colliding beam accelerator - to carry out thermonuclear fusion.

Tokamak requires very small amounts of lithium and deuterium to operate. For example, a reactor with an electrical power of 1 GW burns about 100 kg of deuterium and 300 kg of lithium per year. If we assume that all fusion power plants will produce 10 trillion. kWh of electricity per year, that is, the same amount as all the Earth’s power plants produce today, then the world’s reserves of deuterium and lithium are enough to supply humanity with energy for many millions of years.

In addition to the fusion of deuterium and lithium, purely solar fusion is possible when two deuterium atoms combine. If this reaction is mastered, energy problems will be solved immediately and forever.

In any of the known variants of controlled thermonuclear fusion (CTF), thermonuclear reactions cannot enter the mode of uncontrolled increase in power, therefore, such reactors are not inherently safe.

From a physical point of view, the problem is formulated simply. To carry out a self-sustaining nuclear fusion reaction, it is necessary and sufficient to meet two conditions.

1. The energy of the nuclei involved in the reaction must be at least 10 keV. For nuclear fusion to occur, the nuclei participating in the reaction must fall into the field of nuclear forces, the radius of which is 10-12-10-13 cm. However, atomic nuclei have a positive electrical charge, and like charges repel. At the boundary of the action of nuclear forces, the Coulomb repulsion energy is on the order of 10 keV. To overcome this barrier, the nuclei upon collision must have a kinetic energy at least not less than this value.

2. The product of the concentration of reacting nuclei and the retention time during which they retain the specified energy must be at least 1014 s.cm-3. This condition - the so-called Lawson criterion - determines the limit of the energetic benefit of the reaction. In order for the energy released in the fusion reaction to at least cover the energy costs of initiating the reaction, atomic nuclei must undergo many collisions. In each collision in which a fusion reaction occurs between deuterium (D) and tritium (T), 17.6 MeV of energy is released, i.e. approximately 3.10-12 J. If, for example, 10 MJ of energy is spent on ignition, then the reaction will be unprofitable if at least 3.1018 D-T pairs take part in it. And for this, a fairly dense high-energy plasma needs to be kept in the reactor for quite a long time. This condition is expressed by the Lawson criterion.

If both requirements can be met simultaneously, the problem of controlled thermonuclear fusion will be solved.

However, the technical implementation of this physical problem faces enormous difficulties. After all, an energy of 10 keV is a temperature of 100 million degrees. A substance can only be kept at this temperature for even a fraction of a second in a vacuum, isolating it from the walls of the installation.

But there is another method of solving this problem - cold fusion. What is a cold thermonuclear reaction? It is an analogue of a “hot” thermonuclear reaction taking place at room temperature.

In nature, there are at least two ways of changing matter within one dimension of the continuum. You can boil water over a fire, i.e. thermally, or in a microwave oven, i.e. frequency. The result is the same - the water boils, the only difference is that the frequency method is faster. Achieving ultra-high temperatures is also used to split the nucleus of an atom. The thermal method produces an uncontrollable nuclear reaction. The energy of a cold thermonuclear is the energy of the transition state. One of the main conditions for the design of a reactor for carrying out a cold thermonuclear reaction is the condition of its pyramidal crystalline shape. Another important condition is the presence of rotating magnetic and torsion fields. The intersection of fields occurs at the point of unstable equilibrium of the hydrogen nucleus.

Scientists Ruzi Taleyarkhan from Oak Ridge National Laboratory, Richard Lahey from Polytechnic University. Rensilira and academician Robert Nigmatulin recorded a cold thermonuclear reaction in laboratory conditions.

The group used a beaker of liquid acetone the size of two to three glasses. Sound waves were intensely transmitted through the liquid, producing an effect known in physics as acoustic cavitation, which results in sonoluminescence. During cavitation, small bubbles appeared in the liquid, which increased to two millimeters in diameter and exploded. The explosions were accompanied by flashes of light and the release of energy i.e. the temperature inside the bubbles at the moment of explosion reached 10 million degrees Kelvin, and the released energy, according to experimenters, is enough to carry out thermonuclear fusion.

“Technically,” the essence of the reaction is that as a result of the combination of two deuterium atoms, a third is formed - an isotope of hydrogen, known as tritium, and a neutron, characterized by a colossal amount of energy.

The current in the superconducting state is zero, and, therefore, a minimum amount of electricity will be consumed to maintain the magnetic field. 8. Ultra-fast systems. Controlled thermonuclear fusion with inertial confinement The difficulties associated with magnetic confinement of plasma can, in principle, be circumvented if nuclear fuel is burned in extremely short times, when...

For 2004. The next negotiations on this project will take place in May 2004 in Vienna. The reactor will begin to be created in 2006 and are planned to be launched in 2014. Operating principle Thermonuclear fusion* is a cheap and environmentally friendly way of producing energy. Uncontrolled thermonuclear fusion has been occurring on the Sun for billions of years - helium is formed from the heavy hydrogen isotope deuterium. Wherein...

The experimental thermonuclear reactor is headed by E.P. Velikhov. The United States, having spent 15 billion dollars, left this project, the remaining 15 billion has already been spent by international scientific organizations. 2. Technical, environmental and medical problems. During the operation of controlled thermonuclear fusion (CTF) installations. neutron beams and gamma radiation arise, and also arise...

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Despite statements full of absolute confidence from quite authoritative foreign experts about the imminent use of energy that can finally be obtained from thermonuclear reactors, everything is not so optimistic. Thermonuclear energy, seemingly so understandable and accessible, is in fact still far from widespread and widespread implementation in practice. Recently, rosy messages have reappeared on the Internet, assuring the general public that “there are virtually no technical obstacles left to the creation of a fusion reactor in the near future.” But such confidence was there before. It seemed like a very promising and solvable problem. But dozens of years have passed, and the cart, as they say, is still there. A highly efficient environmentally friendly source of energy still remains beyond the control of humanity. As before, this is a promising subject of research and development, which will someday culminate in a successful project - and then energy will come to us as if from a cornucopia. But the fact is that such a long progress forward, more like marking time, makes you think very seriously and evaluate the current situation. What if we underestimate some important factors, do not take into account the significance and role of any parameters. After all, even in the Solar System there is a thermonuclear reactor that has not come into operation. This is the planet Jupiter. The lack of mass and gravitational compression did not allow this representative of the giant planets to reach the required power and become another Sun in the Solar System. It turns out that just as for conventional nuclear fuel there is a critical mass necessary for a chain reaction to occur, so in this case there are limiting parameters. And if, in order to somehow circumvent the restrictions on the minimum required mass when using a traditional nuclear charge, compression of the material during the explosion is used, then in the case of creating thermonuclear installations, certain non-standard solutions are also needed.

The problem is that plasma must not only be obtained, but also retained. We need stability in the operation of the thermonuclear reactor being created. But this is a big problem.

Of course, no one will argue about the benefits of thermonuclear fusion. This is an almost unlimited resource for obtaining energy. But the director of the Russian agency ITER (we are talking about the international experimental thermonuclear reactor) rightly noted that more than 10 years ago the USA and England received energy from thermonuclear installations, but its output was far from the invested power. The maximum was even less than 70%. But the modern project (ITER) involves obtaining 10 times more power compared to the investment. Therefore, statements that the project is technically complex and that adjustments will be made to it, as well as, of course, to the launch dates of the reactor, and, consequently, the return of investment to the states that have invested in this development, are very alarming.

Thus, the question arises, how justified is the attempt to replace the powerful gravity that holds the plasma in natural thermonuclear reactors (stars) with magnetic fields - the result of the creation of human engineering? The advantage of thermonuclear fusion - the release of energy is millions of times greater than the heat release that occurs, for example, when burning conventional fuel - - it is this, at the same time, that is an obstacle to the successful curbing of the energy breaking free. What is easily solved by a sufficient level of gravity becomes an incredibly difficult task for engineers and scientists. This is why it is so difficult to share the optimism regarding the immediate prospects for thermonuclear energy. There is a much greater chance of using a natural thermonuclear reactor - the Sun. This energy will last for at least another 5 billion years. And due to it, photocells, thermoelements and even some steam boilers will work, for which the water would be heated using lenses or spherical mirrors.

Bibliographic link

Silaev I.V., Radchenko T.I. PROBLEMS OF CREATION OF INSTALLATIONS FOR THERMONUCLEAR fusion // International Journal of Applied and Fundamental Research. – 2014. – No. 1. – P. 37-38;
URL: https://applied-research.ru/ru/article/view?id=4539 (date of access: 09/19/2019). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"

Sivkova Olga Dmitrievna

This work took 3rd place at the regional educational institution

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Municipal educational institution

Secondary school No. 175

Leninsky district of N. Novgorod

Problems of thermonuclear fusion

Completed by: Sivkova Olga Dmitrievna

Student of class 11 “A”, school No. 175

Scientific adviser:

Kirzhaeva D. G.

Nizhny Novgorod

year 2013.

Introduction 3

2. Controlled thermonuclear fusion 8

3. Advantages of thermonuclear fusion 10

4. Problems of thermonuclear fusion 12

4.1 Environmental issues 15

4.2 Medical problems 16

5. Thermonuclear installations 18

6. Prospects for the development of thermonuclear fusion 23

Conclusion 26

Literature 27

Introduction

According to various forecasts, the main sources of electricity on the planet will run out in 50-100 years. Humanity will exhaust its oil reserves in 40 years, gas reserves in a maximum of 80 years, and uranium reserves in 80-100 years. Coal reserves may last for 400 years. But the use of this organic fuel, and as the main one, puts the planet on the brink of environmental disaster. If such merciless air pollution is not stopped today, centuries are out of the question. This means that we need an alternative source of energy in the foreseeable future.

And there is such a source. This is thermonuclear energy, which uses absolutely non-radioactive deuterium and radioactive tritium, but in volumes thousands of times smaller than in nuclear energy. And this source is practically inexhaustible, it is based on the collision of hydrogen nuclei, and hydrogen is the most common substance in the Universe.

One of the most important tasks facing humanity in this area isproblem of controlled thermonuclear fusion.

Human civilization cannot exist, much less develop, without energy. Everyone understands well that the developed energy sources, unfortunately, may soon be depleted. According to the World Energy Council, there are 30 years of proven hydrocarbon fuel reserves left on Earth.

Today the main sources of energy are oil, gas and coal.

According to experts, the reserves of these minerals are running out. There are almost no explored, exploitable oil fields left, and our grandchildren may already face a very serious problem of energy shortages.

The most fuel-rich nuclear power plants could, of course, supply humanity with electricity for hundreds of years.

Object of study: Problems controlled thermonuclear fusion.

Subject of study:Thermonuclear fusion.

Purpose of the study:Solve the problem of thermonuclear fusion control;

Research objectives:

Study the types of thermonuclear reactions.
Consider all possible options for conveying the energy released during a thermonuclear reaction to a person.
Propose a theory about the conversion of energy into electricity.

Background fact:

Nuclear energy is released during the decay or fusion of atomic nuclei. Any energy - physical, chemical, or nuclear - is manifested by its ability to perform work, emit heat or radiation. Energy in any system is always conserved, but it can be transferred to another system or changed in form.

Achievement The conditions for controlled thermonuclear fusion are hampered by several main problems:

First, you need to heat the gas to a very high temperature.
Secondly, it is necessary to control the number of reacting nuclei over a sufficiently long time.
Thirdly, the amount of energy released must be greater than what was expended to heat and limit the density of the gas.
The next problem is storing this energy and converting it into electricity.

1. Thermonuclear reactions on the Sun

What is the source of solar energy? What is the nature of the processes that produce enormous amounts of energy? How long will the sun continue to shine?

The first attempts to answer these questions were made by astronomers in the middle of the 19th century, after physicists formulated the law of conservation of energy.

Robert Mayer suggested that the Sun shines due to the constant bombardment of the surface by meteorites and meteoric particles. This hypothesis was rejected, since a simple calculation shows that in order to maintain the luminosity of the Sun at the current level, it is necessary for 2∙10 to fall on it every second. 15 kg of meteoric material. Over the course of a year this will amount to 6∙10 22 kg, and during the existence of the Sun, over 5 billion years - 3∙10 32 kg. Solar mass M = 2∙10 30 kg, so in five billion years, matter 150 times the mass of the Sun should have fallen onto the Sun.

The second hypothesis was expressed by Helmholtz and Kelvin also in the middle of the 19th century. They suggested that the Sun radiates due to compression by 60–70 meters annually. The reason for the compression is the mutual attraction of particles of the Sun, which is why this hypothesis was called contractionary . If we make a calculation according to this hypothesis, then the age of the Sun will be no more than 20 million years, which contradicts modern data obtained from the analysis of the radioactive decay of elements in geological samples of the Earth’s soil and the soil of the Moon.

The third hypothesis about possible sources of solar energy was expressed by James Jeans at the beginning of the twentieth century. He suggested that the depths of the Sun contain heavy radioactive elements that spontaneously decay and emit energy. For example, the transformation of uranium into thorium and then into lead is accompanied by the release of energy. Subsequent analysis of this hypothesis also showed its inconsistency; a star consisting of only uranium would not release enough energy to produce the observed luminosity of the Sun. In addition, there are stars whose luminosity is many times greater than that of our star. It is unlikely that those stars will also have larger reserves of radioactive material.

The most probable hypothesis turned out to be the hypothesis of the synthesis of elements as a result of nuclear reactions in the bowels of stars.

In 1935, Hans Bethe hypothesized that the source of solar energy could be the thermonuclear reaction of converting hydrogen into helium. It was for this that Bethe received the Nobel Prize in 1967.

The chemical composition of the Sun is about the same as that of most other stars. Approximately 75% is hydrogen, 25% is helium and less than 1% is all other chemical elements (mainly carbon, oxygen, nitrogen, etc.). Immediately after the birth of the Universe, there were no “heavy” elements at all. All of them, i.e. elements heavier than helium, and even many alpha particles, were formed during the “burning” of hydrogen in stars during thermonuclear fusion. The characteristic lifetime of a star like the Sun is ten billion years.

The main source of energy isproton-proton cycle – very slow reaction (characteristic time 7.9∙10 9 years), since it is due to weak interaction. Its essence is that a helium nucleus is formed from four protons. In this case, a pair of positrons and a pair of neutrinos are released, as well as 26.7 MeV of energy. The number of neutrinos emitted by the Sun per second is determined only by the luminosity of the Sun. Since 2 neutrinos are born when 26.7 MeV is released, the neutrino emission rate is: 1.8∙10 38 neutrino/s. A direct test of this theory is the observation of solar neutrinos. High-energy (boron) neutrinos are detected in chlorine-argon experiments (Davis experiments) and consistently show a lack of neutrinos compared to the theoretical value for the standard model of the Sun. Low-energy neutrinos arising directly in the pp reaction are recorded in gallium-germanium experiments (GALLEX in Gran Sasso (Italy - Germany) and SAGE in Baksan (Russia - USA)); they are also "missing".

According to some assumptions, if neutrinos have a rest mass different from zero, oscillations (transformations) of different types of neutrinos are possible (the Mikheev – Smirnov – Wolfenstein effect) (there are three types of neutrinos: electron, muon and tauon neutrinos). Because Since other neutrinos have much smaller cross sections for interaction with matter than electrons, the observed deficit can be explained without changing the standard model of the Sun, built on the basis of the entire set of astronomical data.

Every second, the Sun processes about 600 million tons of hydrogen. Nuclear fuel reserves will last for another five billion years, after which it will gradually turn into a white dwarf.

The central parts of the Sun will contract, heating up, and the heat transferred to the outer shell will lead to its expansion to sizes monstrous compared to modern ones: the Sun will expand so much that it will absorb Mercury, Venus and will consume “fuel” a hundred times faster, than at present. This will lead to an increase in the size of the Sun; our star will become a red giant, the size of which is comparable to the distance from the Earth to the Sun!

We will, of course, be aware of such an event in advance, since the transition to a new stage will take approximately 100-200 million years. When the temperature of the central part of the Sun reaches 100,000,000 K, helium will begin to burn, turning into heavy elements, and the Sun will enter the stage of complex cycles of compression and expansion. At the last stage, our star will lose its outer shell, the central core will have an incredibly high density and size, like that of the Earth. A few more billion years will pass, and the Sun will cool down, turning into a white dwarf.

2. Controlled thermonuclear fusion.

Controlled thermonuclear fusion (CTF) is the synthesis of heavier atomic nuclei from lighter ones in order to obtain energy, which, unlike explosive thermonuclear fusion (used in thermonuclear weapons), is of a controlled nature. Controlled thermonuclear fusion differs from traditional nuclear energy in that the latter uses a decay reaction, during which lighter nuclei are produced from heavy nuclei. The main nuclear reactions planned to be used to achieve controlled thermonuclear fusion will use deuterium ( 2 H) and tritium (3 H), and in the longer term helium-3 ( 3 He) and boron-11 (11 B).

Controlled fusion can use different types of fusion reactions depending on the type of fuel used.

Deuterium is a thermonuclear fuel. 2 D 1, tritium 3 T 1 and 6 Li 3 . The primary nuclear fuel of this type is deuterium. 6 Li 3 serves as a raw material for the production of secondary thermonuclear fuel – tritium.

Tritium 3 T 1 - superheavy hydrogen 3 N 1 – obtained by irradiation of natural Li ( 7.52% 6 Li 3 ) neutrons and alpha particles ( 4 α 2 - helium atom nuclei 4 Not 2 ). Deuterium mixed with tritium and 6 Li 3 (in the form of LiD and LiТ ). When nuclear fusion reactions are carried out in fuel, fusion reactions of helium nuclei occur (at temperatures of tens to hundreds of millions of degrees). Emitted neutrons are absorbed by nuclei 6 Li 3 , in this case an additional amount of tritium is formed according to the reaction: 6 Li 3 + 1 p 0 = 3 T 1 + 4 He 2 ( in the reaction of the sum of mass numbers 6+1=3+4 and sum of charges 3+0=1+2 must be the same on both sides of the equation). As a result of the fusion reaction, two deuterium nuclei (heavy hydrogen) produce one tritium nucleus (superheavy hydrogen) and a proton (nucleus of a normal hydrogen atom): 2 D 1 + 2 D 1 = 3 T 1 + 1 P 1; The reaction can proceed along a different path, with the formation of a helium isotope nucleus 3 He 2 and neutron 1 n 0: 2 D 1 + 2 D 1 = 3 He 2 + 1 n 0. Tritium reacts with deuterium, neutrons appear again that can interact with 6 Li 3: 2 D 1 + 3 T 1 = 4 He 2 + 1 n 0 etc. The calorific value of thermonuclear fuel is 5–6 times higher than that of fissile materials. Deuterium reserves in the hydrosphere are of the order of 10 13 t . However, at present, only uncontrolled reactions (explosion) are practically carried out; a widespread search is being carried out for methods of implementing a controlled thermonuclear reaction, which in principle makes it possible to provide humanity with energy for an almost unlimited period.

3.Advantages of thermonuclear fusion

What advantages does thermonuclear fusion have over nuclear fission reactions, which allow us to hope for the large-scale development of thermonuclear energy? The main and fundamental difference is the absence of long-lived radioactive waste, which is typical for nuclear fission reactors. And although during the operation of a thermonuclear reactor the first wall is activated by neutrons, the choice of suitable low-activation structural materials opens up the fundamental possibility of creating a thermonuclear reactor in which the induced activity of the first wall will decrease to a completely safe level thirty years after the reactor is shut down. This means that an exhausted reactor will need to be mothballed for only 30 years, after which the materials can be recycled and used in a new synthesis reactor. This situation is fundamentally different from fission reactors, which produce radioactive waste that requires reprocessing and storage for tens of thousands of years. In addition to low radioactivity, thermonuclear energy has huge, practically inexhaustible reserves of fuel and other necessary materials, sufficient to produce energy for many hundreds, if not thousands of years.

It was these advantages that prompted the major nuclear countries to begin large-scale research on controlled thermonuclear fusion in the mid-50s. By this time, the first successful tests of hydrogen bombs had already been carried out in the Soviet Union and the United States, which confirmed the fundamental possibility of using nuclear fusion energy in terrestrial conditions. From the very beginning, it became clear that controlled thermonuclear fusion had no military application. The research was declassified in 1956 and has since been carried out within the framework of widespread international cooperation. The hydrogen bomb was created in just a few years, and at that time it seemed that the goal was close, and that the first large experimental facilities, built in the late 50s, would produce thermonuclear plasma. However, it took more than 40 years of research to create conditions under which the release of thermonuclear power is comparable to the heating power of the reacting mixture. In 1997, the largest thermonuclear installation, the European TOKAMAK (JET), received 16 MW of thermonuclear power and came close to this threshold.

What was the reason for this delay? It turned out that in order to achieve the goal, physicists and engineers had to solve a lot of problems that they had no idea about at the beginning of the journey. During these 40 years, the science of plasma physics was created, which made it possible to understand and describe the complex physical processes occurring in the reacting mixture. Engineers needed to solve equally complex problems, including learning how to create deep vacuums in large volumes, selecting and testing suitable construction materials, developing large superconducting magnets, powerful lasers and X-ray sources, developing pulsed power systems capable of creating powerful beams of particles, develop methods for high-frequency heating of the mixture and much more.

4. Problems of controlled thermonuclear fusion

From a physical point of view, the problem is formulated simply. To carry out a self-sustaining nuclear fusion reaction, it is necessary and sufficient to meet two conditions.

The energy of the nuclei involved in the reaction must be at least 10 keV. For nuclear fusion to occur, the nuclei participating in the reaction must fall into the field of nuclear forces, the radius of which is 10-12-10-13 cm. However, atomic nuclei have a positive electrical charge, and like charges repel. At the boundary of the action of nuclear forces, the Coulomb repulsion energy is on the order of 10 keV. To overcome this barrier, the nuclei upon collision must have a kinetic energy at least not less than this value.
The product of the concentration of reacting nuclei and the retention time during which they retain the specified energy must be at least 1014 s.cm-3. This condition - the so-called Lawson criterion - determines the limit of the energetic benefit of the reaction. In order for the energy released in the fusion reaction to at least cover the energy costs of initiating the reaction, atomic nuclei must undergo many collisions. In each collision in which a fusion reaction occurs between deuterium (D) and tritium (T), 17.6 MeV of energy is released, i.e. approximately 3.10-12 J. If, for example, 10 MJ of energy is spent on ignition, then the reaction will be unprofitable if at least 3.1018 D-T pairs take part in it. And for this, a fairly dense high-energy plasma needs to be kept in the reactor for quite a long time. This condition is expressed by the Lawson criterion.

If both requirements can be met simultaneously, the problem of controlled thermonuclear fusion will be solved.

But there is another method of solving this problem - cold fusion. What is a cold thermonuclear reaction? It is an analogue of a “hot” thermonuclear reaction taking place at room temperature.

4.1 Economic problems

When creating a TCB, it is assumed that it will be a large installation equipped with powerful computers. It will be a whole small city. But in the event of an accident or equipment breakdown, the operation of the station will be disrupted.

This is not provided for, for example, in modern nuclear power plant designs. It is believed that the main thing is to build them, and what happens afterwards is not important.

But if 1 station fails, many cities will be left without electricity. This can be observed in the example of nuclear power plants in Armenia. Removing radioactive waste has become very expensive. At the request of the greens, the nuclear power plant was closed. The population was left without electricity, the power plant equipment was worn out, and the money allocated by international organizations for restoration was wasted.

A serious economic problem is the decontamination of abandoned production facilities where uranium was processed. For example, “the city of Aktau has its own little “Chernobyl”. It is located on the territory of the chemical-hydrometallurgical plant (KHMP). Gamma background radiation in the uranium processing workshop (HMC) in some places reaches 11,000 micro-roentgens per hour, the average background level is 200 micro-roentgens ( The usual natural background is from 10 to 25 microroentgens per hour). After the plant was stopped, no decontamination was carried out here at all. A significant part of the equipment, about fifteen thousand tons, already has irremovable radioactivity. At the same time, such dangerous objects are stored in the open air, poorly guarded and constantly taken away from the territory of KhGMZ.

Therefore, since there are no eternal productions, due to the emergence of new technologies, the TTS may be closed and then objects and metals from the enterprise will end up on the market and the local population will suffer.

The cooling system of the UTS will use water. But according to environmentalists, if we take statistics from nuclear power plants, the water from these reservoirs is not suitable for drinking.

According to experts, the reservoir is full of heavy metals (in particular, thorium-232), and in some places the level of gamma radiation reaches 50 - 60 microroentgens per hour.

That is, now, during the construction of a nuclear power plant, no means are provided that would return the area to its original state. And after the closure of the enterprise, no one knows how to bury the accumulated waste and clean up the former enterprise.

4.2 Medical problems

The harmful effects of CTS include the production of mutants of viruses and bacteria that produce harmful substances. This is especially true for viruses and bacteria found in the human body. The appearance of malignant tumors and cancer will most likely be a common disease among residents of villages living near the UTS. Residents always suffer more because they have no means of protection. Dosimeters are expensive and medications are not available. Waste from the CTS will be dumped into rivers, vented into the air, or pumped into underground layers, as is currently happening at nuclear power plants.

In addition to the damage that appears soon after exposure to high doses, ionizing radiation causes long-term consequences. Mainly carcinogenesis and genetic disorders that can occur with any dose and type of radiation (one-time, chronic, local).

According to reports from doctors who recorded diseases of nuclear power plant workers, cardiovascular diseases (heart attacks) come first, then cancer. The heart muscle becomes thinner under the influence of radiation, becoming flabby and less strong. There are completely incomprehensible diseases. For example, liver failure. But why this happens, none of the doctors still knows. If radioactive substances enter the respiratory tract during an accident, doctors cut out the damaged tissue of the lung and trachea and the disabled person walks with a portable device for breathing

5. Thermonuclear installations

Scientists in our country and most developed countries of the world have been studying the problem of using thermonuclear reactions for energy purposes for many years. Unique thermonuclear installations have been created - highly complex technical devices designed to study the possibility of obtaining colossal energy, which so far is released only during the explosion of a hydrogen bomb. Scientists want to learn how to control the course of a thermonuclear reaction - the reaction of heavy hydrogen nuclei (deuterium and tritium) combining to form helium nuclei at high temperatures - in order to use the energy released for peaceful purposes, for the benefit of people.

A liter of tap water contains very little deuterium. But if this deuterium is collected and used as fuel in a thermonuclear installation, then you can get as much energy as from burning almost 300 kilograms of oil. And to provide the energy that is now obtained by burning conventional fuel produced per year, it would be necessary to extract deuterium from water contained in a cube with a side of only 160 meters. The Volga River alone annually carries about 60,000 such cubic meters of water into the Caspian Sea.

For a thermonuclear reaction to occur, several conditions must be met. Thus, the temperature in the zone where heavy hydrogen nuclei combine should be approximately 100 million degrees. At such an enormous temperature, we are no longer talking about gas, but about plasma. Plasma is a state of matter when, at high gas temperatures, neutral atoms lose their electrons and turn into positive ions. In other words, plasma is a mixture of freely moving positive ions and electrons. The second condition is the need to maintain a plasma density in the reaction zone of at least 100 thousand billion particles per cubic centimeter. And finally, the main and most difficult thing is to keep the progress of the thermonuclear reaction at least for at least one second.

The working chamber of a thermonuclear installation is toroidal, similar to a huge hollow donut. It is filled with a mixture of deuterium and tritium. Inside the chamber itself, a plasma coil is created - a conductor through which an electric current of about 20 million amperes is passed.
Electric current performs three important functions. First, it creates plasma. Secondly, it heats it up to one hundred million degrees. And finally, the current creates a magnetic field around itself, that is, it surrounds the plasma with magnetic lines of force. In principle, the lines of force around the plasma should keep it suspended and prevent the plasma from coming into contact with the walls of the chamber. However, keeping the plasma suspended is not so simple. Electrical forces deform the plasma conductor, which does not have the strength of a metal conductor. It bends, hits the wall of the chamber and gives off its thermal energy to it. To prevent this, coils are placed on top of the toroidal chamber, creating a longitudinal magnetic field in the chamber, pushing the plasma conductor away from the walls. Only this turns out to be not enough, since the plasma conductor with current tends to stretch and increase its diameter. The magnetic field, which is created automatically, without extraneous external forces, is also designed to keep the plasma conductor from expanding. The plasma conductor is placed along with the toroidal chamber in another larger chamber made of a non-magnetic material, usually copper. As soon as the plasma conductor attempts to deviate from the equilibrium position, an induced current appears in the copper shell, according to the law of electromagnetic induction, in the opposite direction to the current in the plasma. As a result, a counterforce appears, repelling the plasma from the walls of the chamber.
It was proposed in 1949 by A.D. to keep the plasma from contact with the walls of the chamber by a magnetic field. Sakharov, and a little later the American J. Spitzer.

In physics, it is customary to give names to each new type of experimental setup. A structure with such a winding system is called a tokamak - short for “toroidal chamber and magnetic coil”.

In the 1970s, the USSR built a thermonuclear plant called Tokamak-10. It was developed at the Institute of Atomic Energy named after. I.V. Kurchatova. Using this installation, we obtained a plasma conductor temperature of 10 million degrees, a plasma density of at least 100 thousand billion particles per cubic centimeter, and a plasma retention time of close to 0.5 seconds. The largest installation in our country today, Tokamak-15, was also built at the Moscow scientific center Kurchatov Institute.

All created thermonuclear installations so far only consume energy to heat the plasma and create magnetic fields. The thermonuclear installation of the future should, on the contrary, release so much energy that a small part of it can be used to maintain the thermonuclear reaction, that is, heating the plasma, creating magnetic fields and powering many auxiliary devices and instruments, and the main part can be given for consumption to the electrical network.

In 1997, in the UK, the JET tokamak achieved a match between the input and output energy. Although this, of course, is not enough for the process to self-sustain: up to 80 percent of the energy received is lost. In order for the reactor to work, it is necessary to produce five times more energy than is spent on heating the plasma and creating magnetic fields.
In 1986, the countries of the European Union, together with the USSR, the USA and Japan, decided to jointly develop and build by 2010 a large enough tokamak capable of producing energy not only to support thermonuclear fusion in the plasma, but also to produce useful electrical power. This reactor was called ITER, an abbreviation for “international thermonuclear experimental reactor.” By 1998, it was possible to complete design calculations, but due to the American refusal, changes had to be made to the reactor design to reduce its cost.

You can let the particles move naturally and shape the camera to follow their path. The camera then has a rather bizarre appearance. It repeats the shape of a plasma filament arising in the magnetic field of external coils of complex configuration. The magnetic field is created by external coils of a much more complex configuration than in a tokamak. Devices of this kind are called stellarators. The Uragan-3M torsatron was built in our country. This experimental stellarator is designed to contain plasma heated to ten million degrees.

Currently, tokamaks have other serious competitors using inertial thermonuclear fusion. In this case, several milligrams of a deuterium-tritium mixture are enclosed in a capsule with a diameter of 1–2 millimeters. Pulsed radiation from several dozen powerful lasers is focused on the capsule. As a result, the capsule instantly evaporates. You need to put 2 MJ of energy into the radiation in 5–10 nanoseconds. Then the light pressure will compress the mixture to such an extent that a thermonuclear fusion reaction can occur. The energy released during the explosion, equivalent in power to the explosion of one hundred kilograms of TNT, will be converted into a more convenient form - for example, into electricity. However, the construction of stellarators and inertial fusion facilities also faces serious technical difficulties. Probably, the practical use of thermonuclear energy is not a matter of the near future.

6. Prospects for the development of thermonuclear fusion

An important task for the nuclear industry in the long term is to master controlled thermonuclear fusion technologies as the basis of the energy industry of the future. Currently, strategic decisions are being made all over the world on the development and development of new energy sources. The need to develop such sources is associated with the expected shortage of energy production and limited fuel resources. One of the most promising innovative energy sources is controlled thermonuclear fusion (CTF). Fusion energy is released when the nuclei of heavy hydrogen isotopes fuse together. The fuel for a thermonuclear reactor is water and lithium, the reserves of which are practically unlimited. In terrestrial conditions, the implementation of CTS represents a complex scientific and technological problem associated with obtaining a temperature of the substance of more than 100 million degrees and thermal insulation of the synthesis area from the walls of the reactor.

Fusion is a long-term project, with a commercial facility expected to be built by 2040-2050. The most likely scenario for mastering thermonuclear energy involves the implementation of three stages:
- mastering the long-term combustion modes of thermonuclear reactions;
- demonstration of electricity production;
- creation of industrial thermonuclear stations.

As part of the international project ITER (International Thermonuclear Experimental Reactor), it is expected to demonstrate the technical feasibility of plasma confinement and energy generation.The main program goal of the ITER project is to demonstrate the scientific and technical possibility of obtaining energy through reactions of synthesis (fusion) of hydrogen isotopes - deuterium and tritium. The design thermonuclear power of the ITER reactor will be about 500 MW at a plasma temperature of 100 million degrees.
In November 2006, all participants in the ITER project - the European Union, Russia, Japan, the USA, China, Korea and India - signed Agreements on the creation of the International ITER Organization for Fusion Energy for the joint implementation of the ITER project. The construction phase of the reactor began in 2007.

Russia's participation in the ITER project consists of the development, manufacture and delivery of basic technological equipment to the reactor construction site (Cadarache, France) and a monetary contribution amounting in general to about 10% of the total cost of constructing the reactor. The USA, China, India, Korea and Japan have the same share of contribution.
Roadmap for mastering the energy of controlled thermonuclear fusion

2000 (modern level):
Problems to be solved: achieving equality of costs and energy production
The latest generation of tokamaks has made it possible to come close to the implementation of controlled thermonuclear combustion with a large release of energy.
The power of thermonuclear fusion reactions reached the level of 17 MW (JET installation, EU), which is comparable to the power invested in the plasma.
2020:

Problems solved in the ITER project: long-term reaction, development and integration of thermonuclear technologies.

The goal of the ITER project is to achieve controlled ignition of a thermonuclear reaction and its long-term combustion with a tenfold excess of thermonuclear power over the power to initiate the fusion reaction Q³10.

2030:
Problem to be solved: construction of a DEMO demonstration station (DTE)
Selection of optimal materials and technologies for OFC, design, construction and start-up tests of an experimental thermonuclear power plant were completed within the framework of the DEMO project, conceptual design of PFC was completed.
2050
Tasks to be solved: design and construction of PTE, completion of testing of electric power generation technologies at DEMO.
Creation of an industrial energy station with a high safety margin and acceptable economic indicators of energy costs.
Humanity will get its hands on an inexhaustible, environmentally and economically acceptable source of energy.The thermonuclear reactor project is based on Tokamak-type magnetic plasma confinement systems, first developed and implemented in the USSR. In 1968, a plasma temperature of 10 million degrees was reached at the T-3 tokamak. Since that time, Tokamak installations have become a leading direction in research on thermonuclear fusion in all countries.

Currently in use in Russia are tokamaks T-10 and T-15 (RRC "Kurchatov Institute"), T-11M (FSUE State Scientific Center of the Russian Federation TRINITI, Troitsk, Moscow region), Globus-M, FT-2, Tuman-3 (Physical -Technical Institute named after A.F. Ioffe, St. Petersburg, RAS) and the L-2 stellarator (Institute of General Physics, Moscow, RAS).

Conclusion

Based on the conducted research, the following conclusions can be drawn:

Thermonuclear fusion is the most rational, environmentally friendly and cheap way of producing energy, and in terms of the amount of heat produced, it is incomparable with natural sources currently used by humans. Of course, the process of mastering thermonuclear fusion would solve many of humanity’s problems, both in the present and in the future.

In the future, thermonuclear fusion will make it possible to overcome another “crisis of humanity,” namely, overpopulation of the Earth. It is no secret that the development of earthly civilization involves constant and sustainable growth of the planet’s population, so the issue of developing “new territories”, in other words, the colonization of neighboring planets of the solar system to create permanent settlements, is a matter of the very near future.

Literature

A. P. Baskakov. Heat engineering / - M.: Energoatomizdat, 1991
V. I. Krutov. Heat engineering / - M.: Mashinostroenie, 1986
K. V. Tikhomirov. Heat engineering, heat and gas supply and ventilation - M.: Stroyizdat, 1991
V. P. Preobrazhensky. Thermal measurements and instruments - M.: Energia, 1978
Jeffrey P. Freidberg. Plasma Physics and Fusion Energy/ - Cambridge University Press, 2007.
http://www.college.ru./astronomy- Astronomy
http://n-t.ru/tp/ie/ts.htm Thermonuclear fusion on the Sun - a new version Vladimir Vlasov

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Slide captions:

THERMONUCLEAR FUSION

CONCEPT This is a type of nuclear reaction in which light atomic nuclei combine into heavier ones due to the kinetic energy of their thermal motion.

RECEIVING ENERGY

EQUATION FOR THE REACTION WITH THE FORMATION OF HE ⁴

THERMONUCLEAR REACTION IN THE SUN

CONTROLLED THERMONUCLEAR fusion

TOROIDAL CHAMBER WITH MAGNETIC COILS (TOKAMAK)

THE NEED FOR MASTERING THERMONUCLEAR fusion

The extraction of nuclear energy is based on the fundamental fact that the nuclei of chemical elements from the middle of the periodic table are packed tightly, and at the edges of the table, i.e. the lightest and heaviest nuclei are less dense. The iron nuclei and its neighbors in the periodic table are the most densely packed. Therefore, we gain energy in two cases: when we divide heavy nuclei into smaller fragments, and when we glue light nuclei into larger ones.

Accordingly, energy can be extracted in two ways: in nuclear reactions divisions heavy elements - uranium, plutonium, thorium or in nuclear reactions synthesis(adhesion) of light elements - hydrogen, lithium, beryllium and their isotopes. In nature, under natural conditions, both types of reactions are realized. Fusion reactions occur in all stars, including the sun, and are practically the only initial source of energy on Earth - if not directly through sunlight, then indirectly through oil, coal, gas, water and wind. A natural fission reaction took place on Earth about 2 billion years ago in what is now Gabon in Africa: a lot of uranium accidentally accumulated there in one place, and a natural nuclear reactor operated for 100 million years! Then the concentration of uranium decreased, and the natural reactor stalled.

In the middle of the 20th century, humanity began to artificially harness the gigantic energy contained in nuclei. An atomic bomb (uranium, plutonium) “works” on fission reactions, a hydrogen bomb (which is not made of hydrogen at all, but is called that) – on fusion reactions. In a bomb, reactions occur in an instant and are explosive in nature. It is possible to reduce the intensity of nuclear reactions, stretch them out over time, and use them intelligently as a controlled source of energy. Many hundreds of nuclear reactors of various types have been built around the world, where fission reactions take place and heavy elements - uranium, thorium or plutonium - are “burnt”. The task also arose to make the fusion reaction controllable so that it could serve as a source of energy.

It took humanity only a few years to implement a controlled fission reaction. However, the controlled synthesis reaction turned out to be a much more difficult task, which has not yet been fully mastered. The fact is that in order for two light nuclei, for example, deuterium and tritium, to merge, they need to overcome a large potential barrier.

The most straightforward way to achieve this is to accelerate two light nuclei to high energy, so that they themselves break through the barrier. This implies that the mixture of deuterium and tritium must be heated to a very high temperature - about 100 million degrees! At this temperature, the mixture is, of course, ionized, i.e. is plasma. The plasma is held in a donut-shaped vessel by a magnetic field of complex configuration and heated. This installation, the invention of I.E. Tamm, A.D. Sakharov, L.A. Artsimovich and others, is called “tokamak”. The main problem here is to achieve stability of very hot plasma so that it does not “land on the walls” of the vessel. This requires large installation sizes and, accordingly, very strong magnetic fields in a large volume. There are almost no fundamental difficulties here, but there are many technical problems that have not yet been solved.

Recently, construction began on the international ITER facility in the Aix-en-Provence region of France. Russia is also actively participating in the project, contributing 1/11 of the funding. By 2018, the international tokamak should be operational and demonstrate the fundamental possibility of generating energy due to the thermonuclear fusion reaction

Where d– deuterium nucleus (one proton and one neutron), t– tritium nucleus (one proton and two neutrons), He– helium nucleus (two protons and two neutrons), n is a neutron produced as a result of a reaction, and “17.6 MeV” is the energy in mega-electron volts released in a single reaction. This energy is tens of millions of times greater than that released during chemical reactions, for example, during the combustion of organic fuel.

Here the “fuel,” as we see, is a mixture of deuterium and tritium. Deuterium (“heavy water”) is found as a small impurity in any water, and technically it is not difficult to isolate. Its reserves are truly unlimited. Tritium does not occur in nature, since it is radioactive and decays in 12 years. The standard way to produce tritium is from lithium by bombarding it with neutrons. It is assumed that in ITER only a small “seed” of tritium will be needed to start the reaction, and then it will be produced by itself due to the bombardment of the lithium “blanket” with neutrons from reaction (1), i.e. “blankets”, tokamak shells. Therefore, the actual fuel is lithium. There is also a lot of it in the earth’s crust, but it cannot be said that there is an unlimited amount of lithium: if all the energy in the world were produced today due to reaction (1), the explored deposits of the lithium necessary for this would be enough for 1000 years. The explored uranium and thorium will last for approximately the same number of years if energy is produced in conventional nuclear boilers.

One way or another, it is apparently possible to implement a self-sustaining thermonuclear fusion reaction (1) at the current level of science and technology, and there is hope that this will be successfully demonstrated in ten years at the ITER facility. This is a very interesting project both scientifically and technologically, and it is good that our country is participating in it. Moreover, this is not a very common case when Russia is not only at the world level, but in many ways sets this world level.

The question is: can “thermonoxide” serve as the basis for the industrial production of “clean” and “unlimited” energy, as enthusiasts of the project claim. The answer appears to be no, and here's why.

The fact is that the neutrons produced during synthesis (1) themselves are much more valuable than the energy that is released.

But heating teapots with neutrons is robbery,

And here we will give the wasters a fight:

Let's cover the active zone

Uranium blanket - there you go!

(from “The Ballad of Muon Catalysis”, Yu. Dokshitser and D. Dyakonov, 1978)

Indeed, if you cover the surface of a tokamak with a thick “blanket” of the most ordinary natural uranium-238, then under the influence of a fast neutron from reaction (1), the uranium nucleus splits with the release of additional energy of about 200 MeV. Let's pay attention to the numbers:

Fusion reaction (1) produces an energy of 17.6 MeV in a tokomak, plus a neutron

The subsequent fission reaction in the uranium blanket produces about 200 MeV.

Thus, if we have already built a complex thermonuclear installation, then a relatively simple addition to it in the form of a uranium blanket allows us to increase energy production by 12 times!

It is noteworthy that the uranium-238 in the blanket does not have to be very pure or enriched: on the contrary, depleted uranium, of which a lot remains in dumps after enrichment, and even spent nuclear fuel from conventional thermal nuclear power plants, are also suitable. Instead of burying spent fuel, it can be put to great use in a uranium blanket.

In fact, the efficiency increases even more if we consider that a fast neutron, entering a uranium blanket, causes many different reactions, as a result of which, in addition to the release of 200 MeV of energy, several more plutonium nuclei are formed. Thus, the uranium blanket also serves as a powerful producer of new nuclear fuel. The plutonium can then be “burned” at a conventional thermal nuclear power plant, effectively releasing approximately another 340 MeV per plutonium nucleus.

Even taking into account the fact that one of the additional neutrons must be used to reproduce fuel tritium, adding a uranium blanket to the tokamak and several conventional nuclear power plants that are “powered” by plutonium from this blanket makes it possible to increase the energy efficiency of the tokamak at least times in twenty five, and according to some estimates – fifty times! This is all a relatively simple and proven technology. It is clear that not a single sane person, not a single government, not a single commercial organization will miss this opportunity to significantly increase the efficiency of energy production.

If it comes to industrial production, then thermonuclear fusion on a tokomak will essentially be just a “seed”, just a source of precious neutrons, and 96% of the energy will still be produced in fission reactions, and the main fuel will accordingly be uranium-238. Thus, there will never be a “pure” thermonuclear fusion.

Moreover, if the most complex, expensive and least developed part of this chain - thermonuclear fusion - produces less than 4% of the final power, then a natural question arises: is this link even necessary? Maybe there are cheaper and more efficient sources of neutrons?

It is possible that in the near future something completely new will be invented, but there are already developments on how to use other neutron sources instead of thermonuclear in order to easily “burn” natural uranium-238 or thorium. Meaning

Fast neutron breeder reactors

(2nd point of the recent Sarov program)

Electronuclear breeding

Nuclear fusion at low temperatures using muon catalysis.

Each method has its own difficulties and advantages, and each is worthy of a separate story. The nuclear cycle based on thorium also deserves a separate discussion, which is especially important for us, since Russia has more thorium than uranium. India, where the situation is similar, has already chosen thorium as the basis of its future energy. Many people in our country are inclined to believe that the thorium cycle is the most economical and safe method of producing energy in almost unlimited quantities.

Now Russia is at a crossroads: it is necessary to choose an energy development strategy for many decades to come. Selecting the optimal strategy requires open and critical discussion among the scientific and engineering communities about all aspects of the program.

This note is dedicated to the memory of Yuri Viktorovich Petrov (1928-2007), a remarkable scientist and person, Doctor of Physics and Mathematics. Sciences, head of the sector of the St. Petersburg Institute of Nuclear Physics of the Russian Academy of Sciences, who taught the author what is written here.

Yu.V.Petrov, Hybrid nuclear reactors and muon catalysis, in the collection “Nuclear and thermonuclear energy of the future”, M., Energoatomizdat (1987), p. 172.

S.S. Gershtein, Yu.V. Petrov and L.I. Ponomarev, Muon catalysis and nuclear breeding, Advances in Physical Sciences, vol. 160, p. 3 (1990).

In the photo: Yu. V. Petrov (right) and Nobel Prize winner in physics J. ‘t Hooft, photo by D. Dyakonov (1998).