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Thermonuclear reactions in the sun.

 Carbon cycle on the Sun and in the interior of stars How hydrogen turns into helium

Wariness in American society towards fission-based nuclear power has led to increased interest in hydrogen fusion (thermonuclear reaction). This technology has been proposed as an alternative way to harness the properties of the atom to produce electricity. This is a great idea in theory. Hydrogen fusion converts matter into energy more efficiently than nuclear fission, and the process does not produce radioactive waste. However, a functional thermonuclear reactor has yet to be created.

Fusion in the sun

Physicists believe that the Sun converts hydrogen into helium through nuclear fusion reaction. The term "synthesis" means "unification". Hydrogen fusion requires extremely high temperatures. The powerful gravity created by the enormous mass of the Sun constantly maintains its core in a compressed state. This compression ensures the temperature in the core is high enough for thermonuclear fusion of hydrogen to occur.

Deuterium is also known as heavy hydrogen. A deuterium nucleus combines with another proton to form a helium-3 (He-3) nucleus, consisting of two protons and one neutron. In this case, a beam of gamma radiation is emitted. Next, two helium-3 nuclei, formed as a result of two independent repetitions of the process described above, combine to form a helium-4 (He-4) nucleus, consisting of two protons and two neutrons. This isotope of helium is used to fill lighter-than-air balloons. At the final stage, two protons are emitted, which can provoke further development synthesis reactions.

In the process of “solar fusion,” the total mass of matter created is slightly greater than the total mass of the original ingredients. The “missing part” is converted into energy, according to Einstein’s famous formula:

where E is the energy in joules, m is the “missing mass” in kilograms, and c is the speed of light, equal (in vacuum) to 299,792,458 m/s. The Sun produces a colossal amount of energy in this way, as hydrogen nuclei are converted into helium nuclei non-stop and in huge quantities. There is enough matter in the Sun for the process of hydrogen fusion to continue for millions of millennia. Over time, the supply of hydrogen will come to an end, but this will not happen in our lifetime.

To understand the process of birth and development of ideas about thermonuclear fusion on the Sun, it is necessary to know the history of human ideas about understanding this process. There are many insoluble theoretical and technological problems in creating a controlled thermonuclear reactor in which the process of controlling thermonuclear fusion occurs. Many scientists, and especially science officials, are not familiar with the history of this issue.

It was ignorance of the history of humanity’s understanding and understanding of thermonuclear fusion on the Sun that led to the wrong actions of the creators of thermonuclear reactors. This is proven by the sixty-year failure of work to create a controlled thermonuclear reactor, and the wasteful waste of huge amounts of money by many developed countries. The most important and irrefutable proof: a controlled thermonuclear reactor has not been created for 60 years. Moreover, well-known scientific authorities in the media promise the creation of a controlled thermonuclear reactor (CTR) in 30...40 years.

2. Occam's Razor

“Occam’s Razor” is a methodological principle named after the English Franciscan monk and nominalist philosopher William. In a simplified form, it says: “You should not multiply existing things without necessity” (or “You should not attract new entities unless absolutely necessary”). This principle forms the basis of methodological reductionism, also called the principle of parsimony, or the law of economy. Sometimes the principle is expressed in the words: “What can be explained by the lesser should not be expressed by the greater.”

In modern science, Occam's Razor usually refers to a more general principle that states that if there are several logically consistent definitions or explanations of a phenomenon, then the simplest one should be considered correct.

The content of the principle can be simplified to the following: there is no need to introduce complex laws to explain a phenomenon if this phenomenon can be explained by simple laws. Now this principle is a powerful tool of scientific critical thought. Occam himself formulated this principle as a confirmation of the existence of God. To them, in his opinion, everything can definitely be explained without introducing anything new.

Reformulated in the language of information theory, the Occam's Razor principle states that the most accurate message is the message of minimum length.

Albert Einstein reformulated the principle of Occam's Razor as follows: “Everything should be simplified as much as possible, but no more.”

3. About the beginning of humanity’s understanding and presentation of thermonuclear fusion on the Sun

For a long time, all inhabitants of the Earth understood the fact that the Sun warms the Earth, but the sources of solar energy remained unclear to everyone. In 1848, Robert Mayer put forward the meteorite hypothesis, according to which the Sun is heated by bombardment by meteorites. However, with such a necessary number of meteorites, the Earth would also heat up greatly; in addition, the earth's geological strata would consist mainly of meteorites; finally, the mass of the Sun had to increase, and this would affect the movement of the planets.

Therefore, in the second half of the 19th century, many researchers considered the most plausible theory developed by Helmholtz (1853) and Lord Kelvin, who suggested that the Sun is heated due to slow gravitational compression (“Kelvin-Helmholtz mechanism”). Calculations based on this mechanism estimated the maximum age of the Sun at 20 million years, and the time after which the Sun would go out as no more than 15 million. However, this hypothesis contradicted geological data on the age of rocks, which pointed to much higher figures. For example, Charles Darwin noted that the erosion of Vendian deposits continued for at least 300 million years. However, the Brockhaus and Efron encyclopedia considers the gravitational model to be the only acceptable one.

Only in the 20th century was the “correct” solution to this problem found. Rutherford initially hypothesized that the source of the Sun's internal energy was radioactive decay. In 1920, Arthur Eddington suggested that the pressure and temperature in the interior of the Sun were so high that there could be thermonuclear reactions, in which hydrogen nuclei (protons) merge to form a helium-4 nucleus. Since the mass of the latter is less than the sum of the masses of four free protons, then part of the mass in this reaction, according to Einstein’s formula E = mc 2, turns into energy. The fact that hydrogen predominates in the composition of the Sun was confirmed in 1925 by Cecilia Payne.

The theory of nuclear fusion was developed in the 1930s by astrophysicists Chandrasekhar and Hans Bethe. Bethe calculated in detail the two main thermonuclear reactions that are the sources of solar energy. Finally, in 1957, Margaret Burbridge’s work “Synthesis of Elements in Stars” appeared, in which it was shown and suggested that most of the elements in the Universe arose as a result of nucleosynthesis occurring in stars.

4. Space exploration of the Sun

Eddington's first works as an astronomer were related to the study of the movements of stars and the structure of stellar systems. But his main merit is that he created the theory of the internal structure of stars. Deep penetration into the physical essence of phenomena and mastery of the methods of complex mathematical calculations allowed Eddington to obtain a number of fundamental results in such areas of astrophysics as the internal structure of stars, the state of interstellar matter, the movement and distribution of stars in the Galaxy.

Eddington calculated the diameters of some red giant stars and determined the density of the dwarf satellite of the star Sirius - it turned out to be unusually high. Eddington's work on determining the density of a star provided the impetus for the development of the physics of superdense (degenerate) gas.

Eddington was a good interpreter of Einstein's general theory of relativity. He carried out the first experimental test of one of the effects predicted by this theory: the deflection of light rays in the gravitational field of a massive star. He managed to do this during a total eclipse of the Sun in 1919. Together with other scientists, Eddington laid the foundations for modern knowledge about the structure of stars.

5. Thermonuclear fusion - combustion!?

What is, visually, thermonuclear fusion? Basically it's combustion. But it is clear that this is a combustion of very high power per unit volume of space. And it is clear that this is not an oxidation process. Here, in the combustion process, other elements participate, which also burn, but under special physical conditions.

Let's remember combustion.

Chemical combustion is a complex physical and chemical process of converting the components of a combustible mixture into combustion products with the release of thermal radiation, light and radiant energy.

Chemical combustion is divided into several types of combustion.

Subsonic combustion (deflagration), unlike explosion and detonation, occurs at low speeds and is not associated with the formation of a shock wave. Subsonic combustion includes normal laminar and turbulent flame propagation, while supersonic combustion includes detonation.

Combustion is divided into thermal and chain. Thermal combustion is based on a chemical reaction that can proceed with progressive self-acceleration due to the accumulation of released heat. Chain combustion occurs in some gas-phase reactions at low pressures.

Combustion can begin spontaneously as a result of self-ignition or be initiated by ignition. Under fixed external conditions, continuous combustion can occur in a stationary mode, when the main characteristics of the process - reaction rate, heat release power, temperature and composition of products - do not change over time, or in a periodic mode, when these characteristics fluctuate around their average values. Due to the strong nonlinear dependence of the reaction rate on temperature, combustion is highly sensitive to external conditions. This same property of combustion determines the existence of several stationary modes under the same conditions (hysteresis effect).

There is volumetric combustion, it is known to everyone and is often used in everyday life.

Diffusion combustion. It is characterized by separate supply of fuel and oxidizer to the combustion zone. Mixing of components occurs in the combustion zone. Example: combustion of hydrogen and oxygen in a rocket engine.

Combustion of pre-mixed medium. As the name suggests, combustion occurs in a mixture in which both fuel and oxidizer are present. Example: combustion of a gasoline-air mixture in the cylinder of an internal combustion engine after the process is initialized by a spark plug.

Flameless combustion. Unlike conventional combustion, when zones are observed oxidizing flame and reduction flame, it is possible to create conditions for flameless combustion. An example is the catalytic oxidation of organic substances on the surface of a suitable catalyst, for example, the oxidation of ethanol on platinum black.

Smoldering. A type of combustion in which no flame is formed and the combustion zone slowly spreads throughout the material. Smoldering usually occurs in porous or fibrous materials that have a high air content or are impregnated with oxidizing agents.

Autogenous combustion. Self-sustaining combustion. The term is used in waste incineration technologies. The possibility of autogenous (self-sustaining) combustion of waste is determined by the maximum content of ballasting components: moisture and ash.

Flame is a region of space in which combustion occurs in the gas phase, accompanied by visible and (or) infrared radiation.

The usual flame that we observe when a candle, a lighter or a match burns, is a stream of hot gases, elongated vertically due to the gravitational force of the Earth (hot gases tend to rise upward).

6. Modern physical and chemical ideas about the Sun

Main characteristics:

Composition of the photosphere:

The Sun is the central and only star of our Solar system, around which other objects of this system revolve: planets and their satellites, dwarf planets and their satellites, asteroids, meteoroids, comets and cosmic dust. The mass of the Sun (theoretically) is 99.8% of the total mass of the entire solar system. Solar radiation supports life on Earth (photons are necessary for the initial stages of the photosynthesis process) and determines climate.

According to the spectral classification, the Sun belongs to the G2V type (“yellow dwarf”). The surface temperature of the Sun reaches 6000 K, so the Sun shines with almost white light, but due to stronger scattering and absorption of the short-wave part of the spectrum by the Earth's atmosphere, the direct light of the Sun at the surface of our planet acquires a certain yellow tint.

The solar spectrum contains lines of ionized and neutral metals, as well as ionized hydrogen. There are approximately 100 million G2 stars in our Milky Way galaxy. Moreover, 85% of the stars in our galaxy are stars less bright than the Sun (most of them are red dwarfs, which are at the end of their evolutionary cycle). Like all main sequence stars, the Sun produces energy through thermonuclear fusion.

Radiation from the Sun is the main source of energy on Earth. Its power is characterized by the solar constant - the amount of energy passing through a unit area area perpendicular to sun rays. At a distance of one astronomical unit (that is, in Earth's orbit), this constant is approximately 1370 W/m2.

Passing through the Earth's atmosphere, solar radiation loses approximately 370 W/m2 in energy, and up to earth's surface only 1000 W/m2 reaches (in clear weather and when the Sun is at its zenith). This energy can be used in various natural and artificial processes. Thus, plants, using photosynthesis, process it into a chemical form (oxygen and organic compounds). Direct heating by the sun's rays or energy conversion using photocells can be used to generate electricity (solar power plants) or perform other useful work. In the distant past, energy stored in oil and other types of fossil fuels was also obtained through photosynthesis.

The Sun is a magnetically active star. It has a strong magnetic field that varies in strength over time, changing direction approximately every 11 years during solar maximum. Variations magnetic field The suns cause a variety of effects, the totality of which is called solar activity and includes such phenomena as sunspots, solar flares, solar wind variations, etc., and on Earth it causes auroras in high and middle latitudes and geomagnetic storms , which negatively affect the operation of communications, means of transmitting electricity, and also negatively affects living organisms, causing headaches and poor health in people (people sensitive to magnetic storms

). The Sun is a young star of the third generation (population I) with a high metal content, that is, it was formed from the remains of stars of the first and second generations (populations III and II, respectively).

The current age of the Sun (more precisely, the time of its existence on the main sequence), estimated using computer models of stellar evolution, is approximately 4.57 billion years. Life cycle of the Sun.

The Sun is believed to have formed approximately 4.59 billion years ago, when the rapid gravitational compression of a cloud of molecular hydrogen led to the formation of a type 1 T Tauri star in our region of the Galaxy. A star as massive as the Sun should exist on the main sequence for a total of about 10 billion years. Thus, the Sun is now approximately in the middle of its life cycle. On modern stage

Thermonuclear reactions of hydrogen into helium take place in the solar core. Every second in the Sun's core, about 4 million tons of matter is converted into radiant energy, resulting in the generation of solar radiation and a flux of solar neutrinos.

7. Theoretical ideas of humanity about the internal and external structure of the Sun At the center of the Sun is the solar core. The photosphere is the visible surface of the Sun, which is the main source of radiation. The sun is surrounded by a solar corona, which has a very high temperature, but it is extremely rarefied and therefore visible to the naked eye only during periods of complete.

The central part of the Sun with a radius of approximately 150,000 kilometers, in which thermonuclear reactions occur, is called the solar core. The density of the substance in the core is approximately 150,000 kg/m 3 (150 times higher than the density of water and ≈6.6 times higher than the density of the heaviest metal on Earth - osmium), and the temperature in the center of the core is more than 14 million degrees.

Theoretical analysis of data carried out by the SOHO mission showed that in the core the speed of the Sun's rotation around its axis is much higher than on the surface. A proton-proton thermonuclear reaction takes place in the nucleus, as a result of which helium-4 is formed from four protons. At the same time, 4.26 million tons of matter are converted into energy every second, but this value is insignificant compared to the mass of the Sun - 2·10 27 tons.

Above the core, at distances of about 0.2...0.7 solar radii from its center, there is a radiative transfer zone in which there are no macroscopic movements; energy is transferred using the “re-emission” of photons.

Atmosphere of the Sun The photosphere (the layer that emits light) reaches a thickness of ≈320 km and forms the visible surface of the Sun. The main part of the optical (visible) radiation of the Sun comes from the photosphere, but radiation from deeper layers no longer reaches it. The temperature in the photosphere reaches an average of 5800 K. Here, the average gas density is less than 1/1000 of the density of the earth's air, and the temperature decreases to 4800 K as it approaches the outer edge of the photosphere. Hydrogen under such conditions remains almost completely neutral. The photosphere forms the visible surface of the Sun, from which the size of the Sun, distance from the surface of the Sun, etc. are determined. The chromosphere is the outer shell of the Sun, about 10,000 km thick, surrounding the photosphere. The origin of the name of this part of the solar atmosphere is related to its reddish color, caused by the fact that its visible spectrum is dominated by the red H-alpha line of hydrogen emission. The upper boundary of the chromosphere does not have a pronounced smooth surface; hot emissions called spicules constantly occur from it (because of this, late XIX century, the Italian astronomer Secchi, observing the chromosphere through a telescope, compared it to burning prairies). The temperature of the chromosphere increases with altitude from 4000 to 15,000 degrees.

The density of the chromosphere is low, so its brightness is insufficient to observe it under normal conditions. But during a total solar eclipse, when the Moon covers the bright photosphere, the chromosphere located above it becomes visible and glows red. It can also be observed at any time using special narrow-band optical filters.

The corona is the last outer shell of the Sun. Despite its very high temperature, from 600,000 to 2,000,000 degrees, it is visible to the naked eye only during a total solar eclipse, since the density of matter in the corona is low, and therefore its brightness is low. The unusually intense heating of this layer is apparently caused by the magnetic effect and the influence of shock waves. The shape of the corona changes depending on the phase of the solar activity cycle: during periods of maximum activity it has a round shape, and at minimum it is elongated along the solar equator. Since the temperature of the corona is very high, it emits intense radiation in the ultraviolet and x-ray ranges. These radiations do not pass through the earth's atmosphere, but recently it has become possible to study them using spacecraft. Radiation in different areas of the corona occurs unevenly. There are hot active and quiet regions, as well as coronal holes with a relatively low temperature of 600,000 degrees, from which magnetic field lines extend into space. This (“open”) magnetic configuration allows particles to leave the Sun unhindered, so sunny wind is emitted "mostly" from coronal holes.

The solar wind flows from the outer part of the solar corona - a stream of ionized particles (mainly protons, electrons and α-particles), having a speed of 300...1200 km/s and spreading, with a gradual decrease in its density, to the boundaries of the heliosphere.

Since solar plasma has a fairly high electrical conductivity, electric currents and, as a result, magnetic fields can arise in it.

8. Theoretical problems of thermonuclear fusion on the Sun

The problem of solar neutrinos. Nuclear reactions occurring in the core of the Sun lead to the formation of a large number of electron neutrinos. At the same time, measurements of the neutrino flux on Earth, which have been continuously carried out since the late 1960s, have shown that the number of solar electron neutrinos recorded there is approximately two to three times less than predicted by the standard solar model, which describes processes in the Sun. This discrepancy between experiment and theory was called the “solar neutrino problem” and was one of the mysteries of solar physics for more than 30 years. The situation was complicated by the fact that neutrinos interact extremely weakly with matter, and creating a neutrino detector that can accurately measure the neutrino flux even with such power as coming from the Sun is a rather difficult scientific task.

Two main ways to solve the problem of solar neutrinos have been proposed. First, it was possible to modify the model of the Sun in such a way as to reduce the estimated temperature in its core and, therefore, the flux of neutrinos emitted by the Sun. Secondly, it could be assumed that part of the electron neutrinos emitted by the solar core, when moving towards the Earth, turns into neutrinos of other generations that are not detected by conventional detectors (muon and tau neutrinos). Today scientists are inclined to believe that the second path is most likely correct. In order for there to be a transition from one type of neutrino to another - the so-called “neutrino oscillations” - the neutrino must have a non-zero mass. It has now been established that this seems to be true. In 2001, solar neutrinos of all three types were directly detected at the Sudbury Neutrino Observatory and their total flux was shown to be consistent with the standard solar model. At the same time, only about a third of neutrinos reaching the Earth turn out to be electrons. This quantity is consistent with the theory, which predicts the transition of electron neutrinos into neutrinos of another generation both in vacuum (actually “neutrino oscillations”) and in solar matter (“Mikheev-Smirnov-Wolfenstein effect”). Thus, the problem of solar neutrinos is now apparently solved.

Corona heating problem. Above visible surface The sun (photosphere), which has a temperature of about 6,000 K, contains a solar corona with a temperature of more than 1,000,000 K. It can be shown that the direct flow of heat from the photosphere is not enough to lead to such a high temperature of the corona.

It is assumed that the energy for heating the corona is supplied by turbulent movements of the subphotospheric convective zone. In this case, two mechanisms have been proposed for energy transfer to the corona. Firstly, this is wave heating - sound and magnetohydrodynamic waves generated in the turbulent convective zone propagate into the corona and are dissipated there, while their energy is converted into the thermal energy of the coronal plasma. An alternative mechanism is magnetic heating, in which magnetic energy continuously generated by photospheric motions is released through magnetic field reconnection in the form of large solar flares or a large number of small flares.

It is currently unclear what type of waves provides an effective mechanism for heating the corona. It can be shown that all waves, except magnetohydrodynamic Alfvén waves, are scattered or reflected before reaching the corona, while the dissipation of Alfvén waves in the corona is difficult. Therefore, modern researchers have focused their attention on the heating mechanism through solar flares. One of the possible candidates for the sources of heating of the corona is continuously occurring small-scale flares, although final clarity on this issue has not yet been achieved.

P.S. After reading about “Theoretical problems of thermonuclear fusion on the Sun”, you need to remember about “Occam’s Razor”. Here, explanations of theoretical problems clearly use contrived, illogical theoretical explanations.

9. Types of thermonuclear fuel. Fusion fuel

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)

Types of reactions. The fusion reaction is as follows: two or more atomic nuclei are taken and, using a certain force, brought together so close that the forces acting at such distances prevail over the forces of Coulomb repulsion between equally charged nuclei, resulting in the formation of a new nucleus. It will have a slightly smaller mass than the sum of the masses of the original nuclei, and the difference becomes energy, which is released during the reaction. The amount of energy released is described by the well-known formula E = mc 2. Lighter atomic nuclei It is easier to reduce to the required distance, so hydrogen - the most abundant element in the Universe - is the best fuel for the fusion reaction.

It has been found that a mixture of two isotopes of hydrogen, deuterium and tritium, requires the least amount of energy for the fusion reaction compared to the energy released during the reaction. However, although deuterium-tritium (D-T) is the subject of most fusion research, it is by no means the only potential fuel. Other mixtures may be easier to produce; their reaction can be more reliably controlled, or, more importantly, produce fewer neutrons. Of particular interest are the so-called “neutron-free” reactions, since the successful industrial use of such fuel will mean the absence of long-term radioactive contamination of the materials and reactor design, which, in turn, could have a positive impact on public opinion and the overall cost of operating the reactor, significantly reducing the costs of its decommissioning. The problem remains that synthesis reactions using alternative fuels are much more difficult to maintain, so the D-T reaction is considered only a necessary first step.

Scheme of the deuterium-tritium reaction. Controlled fusion can use different kinds thermonuclear reactions depending on the type of fuel used.

The easiest reaction to carry out is deuterium + tritium:

2 H + 3 H = 4 He + n with an energy output of 17.6 MeV.

This reaction is the most easily feasible from the point of view of modern technologies, provides a significant energy yield, and fuel components are cheap. Its disadvantage is the release of unwanted neutron radiation.

Two nuclei: deuterium and tritium merge to form a helium nucleus (alpha particle) and a high-energy neutron.

The reaction - deuterium + helium-3 is much more difficult, at the limit of what is possible, to carry out the reaction deuterium + helium-3:

2 H + 3 He = 4 He + p with an energy output of 18.3 MeV.

The conditions for achieving it are much more complicated. Helium-3 is also a rare and extremely expensive isotope. It is not currently produced on an industrial scale.

Reaction between deuterium nuclei (D-D, monopropellant).

Reactions between deuterium nuclei are also possible; they are a little more difficult than reactions involving helium-3.

These reactions proceed slowly in parallel with the deuterium + helium-3 reaction, and the tritium and helium-3 formed during them are likely to immediately react with deuterium.

Other types of reactions. Some other types of reactions are also possible.

The choice of fuel depends on many factors - its availability and low cost, energy output, ease of achieving the conditions required for the thermonuclear fusion reaction (primarily temperature), the necessary design characteristics of the reactor, etc."Neutronless" reactions.

The most promising are the so-called. “neutron-free” reactions, since the neutron flux generated by thermonuclear fusion (for example, in the deuterium-tritium reaction) carries away a significant part of the power and generates induced radioactivity in the reactor design. The deuterium – helium-3 reaction is promising due to the lack of neutron yield.

10. Classical ideas about the conditions of implementation. thermonuclear fusion and controlled fusion reactors TOKAMAK (TORoidal CHAMBER with MAGNETIC COILS) is a toroidal installation for magnetic plasma confinement. The plasma is held not by the walls of the chamber, which are not able to withstand its temperature, but by a specially created magnetic field. A special feature of TOKAMAK is the use electric current

, flowing through the plasma to create the poloidal field necessary for plasma equilibrium.

• TCB is possible if two criteria are met simultaneously:
• the plasma temperature must be greater than 100,000,000 K; n · compliance with Lawson's criterion: t
  > 5·10 19 cm –3 s (for the D-T reaction), n Where compliance with Lawson's criterion:– density of high-temperature plasma,

– plasma retention time in the system.

It is theoretically believed that the rate of a particular thermonuclear reaction mainly depends on the value of these two criteria.

Two basic schemes for implementing controlled thermonuclear fusion are considered.

Quasi-stationary systems. Heating and confinement of the plasma is carried out by a magnetic field at relatively low pressure and high temperature. For this purpose, reactors are used in the form of TOKAMAKs, stellarators, mirror traps and torsatrons, which differ in the configuration of the magnetic field. The ITER reactor has a TOKAMAK configuration.

Pulse systems. In such systems, CTS is carried out by briefly heating small targets containing deuterium and tritium with ultra-powerful laser or ion pulses. Such irradiation causes a sequence of thermonuclear microexplosions.

Research on the first type of thermonuclear reactor is significantly more developed than on the second. IN nuclear physics, in thermonuclear fusion research, a magnetic trap is used to contain the plasma in a certain volume. The magnetic trap is designed to keep the plasma from contact with the elements of the thermonuclear reactor, i.e. used primarily as a heat insulator. The principle of confinement is based on the interaction of charged particles with a magnetic field, namely on the rotation of charged particles around magnetic field lines. Unfortunately, magnetized plasma is very unstable and tends to leave the magnetic field. Therefore, to create an effective magnetic trap, the most powerful electromagnets are used, consuming a huge amount of energy.

It is possible to reduce the size of a fusion reactor if it uses three methods of creating a fusion reaction simultaneously.

Inertial synthesis. Irradiate tiny capsules of deuterium-tritium fuel with a 500 trillion (5·10 14) W laser. This gigantic, very short 10 –8 s laser pulse causes the fuel capsules to explode, resulting in the birth of a mini-star for a split second. But a thermonuclear reaction cannot be achieved on it.

Simultaneously use the Z-machine with the TOKAMAK. The Z-machine operates differently than a laser. It passes through a web of tiny wires surrounding the fuel capsule a charge with a power of half a trillion watts 5·10 11 W.

First generation reactors will most likely run on a mixture of deuterium and tritium. The neutrons that appear during the reaction will be absorbed by the reactor shield, and the generated heat will be used to heat the coolant in the heat exchanger, and this energy, in turn, will be used to rotate the generator.

There are, in theory, alternative types of fuel that do not have these disadvantages. But their use is hampered by a fundamental physical limitation. To obtain sufficient energy from the fusion reaction, it is necessary to maintain a sufficiently dense plasma at the fusion temperature (10 8 K) for a certain time.

This fundamental aspect of fusion is described by the plasma density product n for the duration of the heated plasma content τ, which is required to reach the equilibrium point. Work nτ depends on the type of fuel and is a function of the plasma temperature. Of all types of fuel, deuterium-tritium mixture requires the lowest value nτ by at least an order of magnitude, and the lowest reaction temperature by at least 5 times. Thus, D-T reaction is a necessary first step, but the use of other fuels remains an important research goal.

11. Fusion reaction as an industrial source of electricity

Fusion energy is considered by many researchers as a "natural" energy source in the long term. Proponents of the commercial use of fusion reactors for electricity production cite the following arguments in their favor:

• practically inexhaustible reserves of fuel (hydrogen);
• fuel can be extracted from sea ​​water on any coast of the world, which makes it impossible for one or a group of countries to monopolize fuel;
• the impossibility of an uncontrolled synthesis reaction;
• absence of combustion products;
• there is no need to use materials that can be used for production nuclear weapons Thus, cases of sabotage and terrorism are excluded;
• Compared to nuclear reactors, a small amount of radioactive waste with a short half-life is produced.

A thimble filled with deuterium is estimated to produce energy equivalent to 20 tons of coal. A medium-sized lake can provide any country with energy for hundreds of years. However, it should be noted that existing research reactors are designed to achieve a direct deuterium-tritium (DT) reaction, the fuel cycle of which requires the use of lithium to produce tritium, while claims of inexhaustible energy refer to the use of deuterium-deuterium (DD) reaction in the second generation of reactors.

Just like the fission reaction, the fusion reaction does not produce atmospheric carbon dioxide emissions, which is a major contributor to global warming. This is a significant advantage, since the use of fossil fuels to produce electricity has the consequence that, for example, the USA produces 29 kg of CO 2 (one of the main gases that can be considered the cause of global warming) per US resident per day.

12. There are already doubts

The countries of the European Community spend about 200 million euros annually on research, and it is predicted that it will take several more decades before the industrial use of nuclear fusion will be possible. Supporters alternative sources electricity authorities believe that it would be more expedient to use these funds to introduce renewable sources of electricity.

Unfortunately, despite widespread optimism (since the 1950s, when the first research began), significant obstacles between today's understanding of nuclear fusion processes, technological capabilities and the practical use of nuclear fusion have not yet been overcome, it is unclear even to what extent there may be It is economically profitable to produce electricity using thermonuclear fusion. Although progress in research is constant, researchers are faced with new challenges every now and then. For example, the challenge is developing a material that can withstand neutron bombardment, which is estimated to be 100 times more intense than traditional nuclear reactors.

13. A classic idea of ​​the upcoming stages in the creation of a controlled thermonuclear reactor

The following stages are distinguished in research.

Equilibrium or “pass” mode: when the total energy released during the synthesis process is equal to the total energy spent on starting and maintaining the reaction. This ratio is marked with the symbol Q. The equilibrium of the reaction was demonstrated at JET in the UK in 1997. Having spent 52 MW of electricity to heat it up, the scientists obtained a power output that was 0.2 MW higher than that expended. (You need to double-check this data!)

Blazing Plasma: an intermediate stage in which the reaction will be supported mainly by alpha particles that are produced during the reaction, rather than by external heating.

Q≈ 5. The intermediate stage has not yet been achieved.

Ignition: a stable reaction that supports itself. Should be achieved at high values Q. Still not achieved.

The next step in research should be ITER, the International Thermonuclear Experimental Reactor. At this reactor it is planned to study the behavior of high-temperature plasma (flaming plasma with Q≈ 30) and structural materials for an industrial reactor.

The final phase of the research will be DEMO: a prototype of an industrial reactor in which ignition will be achieved and the practical suitability of the new materials will be demonstrated. The most optimistic forecast for the completion of the DEMO phase: 30 years. Considering the estimated time for construction and commissioning of an industrial reactor, we are separated by ≈40 years from the industrial use of thermonuclear energy.

14. All this needs to be thought through

Dozens, and maybe hundreds of experimental thermonuclear reactors of various sizes have been built around the world. Scientists come to work, turn on the reactor, the reaction occurs quickly, they seem to turn it off, and sit and think. What is the reason? What to do next? And so for decades, to no avail.

So, above was outlined the history of human understanding about thermonuclear fusion on the Sun and the history of mankind's achievements in creating a controlled thermonuclear reactor.

A long way has been traveled and a lot has been done to achieve the final goal. But, unfortunately, the result is negative. A controlled thermonuclear reactor has not been created. Another 30...40 years and the promises of scientists will be fulfilled. Will there be? 60 years no result. Why should it happen in 30...40 years, and not in three years?

There is another idea about thermonuclear fusion on the Sun. It is logical, simple and really leads to a positive result. This is the discovery of V.F. Vlasova. Thanks to this discovery, even TOKAMAKs may be operational in the near future.

15. A new look at the nature of thermonuclear fusion on the Sun and the invention “Method of controlled thermonuclear fusion and a controlled thermonuclear reactor for implementing controlled thermonuclear fusion”

From the author. This discovery and invention is almost 20 years old. I doubted for a long time what I had found new way carrying out thermonuclear fusion and for its implementation a new thermonuclear reactor. I have researched and studied hundreds of works in the field of thermonuclear fusion. Time and processed information convinced me that I was on the right track.

At first glance, the invention is very simple and does not at all resemble the experimental thermonuclear reactor of the TOKAMAK type. In the modern views of TOKAMAK science authorities, this is the only correct decision and is not subject to discussion. 60 years of the idea of ​​a thermonuclear reactor. But a positive result - a working thermonuclear reactor with controlled thermonuclear fusion TOKAMAK is promised only in 30...40 years. Probably, if there is no real positive result for 60 years, then the chosen method of technical solution to the idea - the creation of a controlled thermonuclear reactor - to put it mildly, is incorrect, or not realistic enough. Let's try to show that there is another solution to this idea based on the discovery of thermonuclear fusion on the Sun, and it differs from generally accepted ideas.

Opening. The main idea of ​​the discovery is very simple and logical, and is that thermonuclear reactions occur in the region of the solar corona. This is where the necessary physical conditions

for the implementation of a thermonuclear reaction. From the Solar corona, where the plasma temperature is approximately 1,500,000 K, the surface of the Sun heats up to 6,000 K, from here the fuel mixture evaporates into the solar corona from the boiling surface of the Sun. A temperature of 6,000 K is enough for the fuel mixture in the form of evaporating vapors to overcome the gravitational force of the Sun. This protects the surface of the Sun from overheating and maintains its surface temperature. Near the combustion zone - the solar corona, there are physical conditions under which the sizes of atoms should change and at the same time the Coulomb forces should significantly decrease. Upon contact, the atoms of the fuel mixture merge and synthesize new elements with a large release of heat. This combustion zone creates the solar corona, from which energy in the form of radiation and matter enters outer space. The fusion of deuterium and tritium is aided by the magnetic field of the rotating Sun, where they are mixed and accelerated. Also, from the thermonuclear reaction zone in the solar corona, fast electrically charged particles, as well as photons - quanta, appear and move with great energy towards the evaporating fuel electromagnetic field

In the classical concepts of physicists, thermonuclear fusion, for some reason, is not classified as a combustion process (here we do not mean the oxidation process). Authorities from physics have come up with the idea that thermonuclear fusion on the Sun repeats the volcanic process on a planet, for example, the Earth. Hence all the reasoning, the similarity technique is used. There is no evidence that the core of planet Earth is in a molten liquid state. Even geophysics cannot reach such depths. The fact that volcanoes exist cannot be considered evidence of a liquid core of the Earth. In the depths of the Earth, especially at shallow depths, there are physical processes that are still unknown to authoritative physicists. There is not a single proof in physics that thermonuclear fusion occurs in the depths of any star. And in a thermonuclear bomb, thermonuclear fusion does not at all repeat the model in the depths of the Sun.

Upon careful visual examination, the Sun looks like a spherical volumetric burner and is very reminiscent of combustion on a large surface of the earth, where between the boundary of the surface and the combustion zone (prototype of the solar corona) there is a gap through which thermal radiation is transmitted to the surface of the earth, which evaporates, for example, spilled fuel and these prepared vapors enter the combustion zone.

It is clear that on the surface of the Sun, such a process occurs under different physical conditions. Similar physical conditions, quite similar in parameters, were incorporated into the development of the design of a controlled thermonuclear reactor, Short description and the schematic diagram of which is set out in the patent application set forth below.

Abstract of patent application No. 2005123095/06(026016).

“Method of controlled thermonuclear fusion and controlled thermonuclear reactor for implementing controlled thermonuclear fusion.”

I explain the method and principle of operation of the claimed controlled thermonuclear reactor for implementing controlled thermonuclear fusion.

Rice. 1. Simplified circuit diagram UTYAR

In Fig. Figure 1 shows a schematic diagram of the UTYAR. Fuel mixture, in a mass ratio of 1:10, compressed to 3000 kg/cm 2 and heated to 3000°C, in the zone 1 mixes and enters through the critical section of the nozzle into the expansion zone 2 . In the zone 3 the fuel mixture is ignited.

The temperature of the ignition spark can be whatever is necessary to start the thermal process - from 109...108 K and below, it depends on the necessary physical conditions created.

In high temperature zone 4 The combustion process takes place directly. Combustion products transfer heat in the form of radiation and convection to the heat exchange system 5 and towards the incoming fuel mixture. Device 6 in the active part of the reactor from the critical section of the nozzle to the end of the combustion zone helps to change the magnitude of the Coulomb forces and increases the effective cross section of the fuel mixture nuclei (creates the necessary physical conditions).

The diagram shows that the reactor is similar to a gas burner. But a thermonuclear reactor should be like this, and of course, the physical parameters will differ by hundreds of times from, for example, the physical parameters of a gas burner.

Repetition of the physical conditions of thermonuclear fusion on the Sun under terrestrial conditions is the essence of the invention.

Any heat-generating device that uses combustion must create the following conditions - cycles: fuel preparation, mixing, supply to the working area (combustion zone), ignition, combustion (chemical or nuclear transformation), heat removal from hot gases in the form of radiation and convection, and removal of combustion products. In case of hazardous waste – its disposal. The claimed patent provides for all this.

The main argument of physicists about the fulfillment of the Lowsen criterion is fulfilled - during ignition by an electric spark or a laser beam, as well as by fast electrically charged particles reflected from the combustion zone by evaporating fuel, as well as photons - electromagnetic field quanta with high-density energies, a temperature of 109 is reached. .108 K for a certain minimum area of ​​fuel, in addition, the density of the fuel will be 10 14 cm –3. Isn't this the way and method to fulfill Lawsen's criterion. But all these physical parameters can change when external factors influence some other physical parameters. This is still know-how.

Let us consider the reasons for the impossibility of implementing thermonuclear fusion in known thermonuclear reactors.

16. Disadvantages and problems of generally accepted ideas in physics about the thermonuclear reaction in the Sun

1. Known. The temperature of the visible surface of the Sun - the photosphere - is 5800 K. The density of gas in the photosphere is thousands of times less than the density of air near the Earth's surface. It is generally accepted that inside the Sun, temperature, density and pressure increase with depth, reaching 16 million K in the center (some say 100 million K), 160 g/cm 3 and 3.5 10 11 bar. Under the influence of high temperatures in the core of the Sun, hydrogen turns into helium, releasing a large amount of heat. So, it is believed that the temperature inside the Sun is from 16 to 100 million degrees, on the surface 5800 degrees, and in the solar corona from 1 to 2 million degrees? Why such nonsense? No one can explain this clearly and understandably. The known generally accepted explanations have shortcomings and do not provide a clear and sufficient idea of ​​the reasons for the violation of the laws of thermodynamics on the Sun.

2. A thermonuclear bomb and a thermonuclear reactor operate on different technological principles, i.e. doesn't look the same. It is impossible to create a thermonuclear reactor in a manner similar to the operation of a thermonuclear bomb, which was missed in the development of modern experimental thermonuclear reactors.

3. In 1920, the authoritative physicist Eddington cautiously suggested the nature of the thermonuclear reaction in the Sun, that the pressure and temperature in the interior of the Sun are so high that thermonuclear reactions can occur there, in which hydrogen nuclei (protons) merge into a helium-4 nucleus. This is currently the generally accepted view. But since then there is no evidence that thermonuclear reactions occur in the core of the Sun at 16 million K (some physicists believe 100 million K), density 160 g/cm3 and pressure 3.5 x 1011 bar, there are only theoretical assumptions . Thermonuclear reactions in the solar corona are evident. This is not difficult to detect and measure.

4. The problem of solar neutrinos. Nuclear reactions occurring in the core of the Sun lead to the formation of a large number of electron neutrinos. According to old concepts, the formation, transformations and number of solar neutrinos are not explained clearly and sufficiently for several decades. New ideas about thermonuclear fusion on the Sun do not have these theoretical difficulties.

5. Corona heating problem. Above the visible surface of the Sun (the photosphere), which has a temperature of about 6,000 K, lies the solar corona, with a temperature of more than 1,500,000 K. It can be shown that the direct flow of heat from the photosphere is not sufficient to lead to such a high temperature of the corona. New understanding of thermonuclear fusion in the Sun explains the nature of this temperature of the solar corona. This is where thermonuclear reactions occur.

6. Physicists forget that TOKAMAKs are mainly needed to contain high-temperature plasma and nothing more. The existing and new TOKAMAKs do not provide for the creation of the necessary, special, physical conditions for thermonuclear fusion. For some reason, no one understands this. Everyone stubbornly believes that at temperatures of many millions, deuterium and tritium should burn well. Why suddenly? A nuclear target simply explodes quickly, rather than burning. Look closely at how nuclear combustion occurs in TOKAMAK. Such nuclear explosion can only withstand the strong magnetic field of a very large reactor (easily calculated), but then the efficiency such a reactor would be unacceptable for technical use. In the claimed patent, the problem of confining thermonuclear plasma is easily solved.

Scientists' explanations about the processes that occur in the depths of the Sun are insufficient to understand thermonuclear fusion in the depths. No one has sufficiently examined the processes of fuel preparation, the processes of heat and mass transfer, at depth, in very difficult critical conditions. For example, how, and under what conditions, is plasma formed at the depth at which thermonuclear fusion occurs? How she behaves, etc. After all, this is exactly how TOKAMAKs are technically designed.

So, the new idea of ​​thermonuclear fusion solves all existing technical and theoretical problems in this area.

P.S. It is difficult to offer simple truths to people who have believed in the opinions (assumptions) of scientific authorities for decades. To understand what the new discovery is about, it is enough to independently reconsider what has been a dogma for many years. If a new proposal about the nature of a physical effect raises doubts about the truth of old assumptions, prove the truth first of all to yourself. This is what every true scientist should do. The discovery of thermonuclear fusion in the solar corona is proven primarily visually. Thermonuclear combustion occurs not in the depths of the Sun, but on its surface. This is a special combustion. Many photographs and images of the Sun show how the combustion process is going on, how the process of plasma formation is going on.

1. Controlled thermonuclear fusion. Wikipedia.

2. Velikhov E.P., Mirnov S.V. Controlled thermonuclear fusion is entering the home stretch. Trinity Institute of Innovation and Thermonuclear Research. Russian science Center"Kurchatov Institute", 2006.

3. Llewellyn-Smith K. On the way to thermonuclear energy. Materials of a lecture given on May 17, 2009 at FIAN.

4. Encyclopedia of the Sun. Tesis, 2006.

5. Sun. Astronet.

6. The sun and the life of the Earth. Radio communications and radio waves.

7. Sun and Earth. Single vibrations.

8. Sun. solar system. General astronomy. Project "Astrogalaxy".

9. Journey from the center of the Sun. Popular Mechanics, 2008.

10. Sun. Physical encyclopedia.

11. Astronomy Picture of the Day.

12. Combustion. Wikipedia.

"Science and Technology"

>What is the Sun made of?

Find out, what is the sun made of: description of the structure and composition of the star, listing of chemical elements, number and characteristics of layers with photos, diagram.

From Earth, the Sun appears as a smooth ball of fire, and before the Galileo spacecraft's discovery of sunspots, many astronomers believed that it was perfectly shaped without defects. Now we know that The sun consists from several layers, like the Earth, each of which performs its own function. This massive furnace-like structure of the Sun is the supplier of all the energy on Earth needed for terrestrial life.

What elements does the Sun consist of?

If you could take the star apart and compare its constituent elements, you would realize that the composition is 74% hydrogen and 24% helium. Also, the Sun consists of 1% oxygen, and the remaining 1% is such chemical elements periodic tables, such as chromium, calcium, neon, carbon, magnesium, sulfur, silicon, nickel, iron. Astronomers believe that an element heavier than helium is a metal.

How did all these elements of the Sun come into being? The Big Bang produced hydrogen and helium. At the beginning of the formation of the Universe, the first element, hydrogen, emerged from elementary particles. Due to the high temperature and pressure, the conditions in the Universe were similar to those in the core of a star. Later, hydrogen was fused into helium while the universe had the high temperature required for the fusion reaction to occur. The existing proportions of hydrogen and helium that are in the Universe now developed after the Big Bang and have not changed.

The remaining elements of the Sun are created in other stars. In the cores of stars, the process of synthesis of hydrogen into helium constantly occurs. After producing all the oxygen in the core, they switch to nuclear fusion of heavier elements such as lithium, oxygen, helium. Many of the heavy metals found in the Sun were formed in other stars at the end of their lives.

The heaviest elements, gold and uranium, were formed when stars many times larger than our Sun detonated. In the split second of the black hole's formation, the elements collided at high speed and the heaviest elements were formed. The explosion scattered these elements throughout the Universe, where they helped form new stars.

Our Sun has collected elements created by the Big Bang, elements from dying stars, and particles created as a result of new star detonations.

What layers does the Sun consist of?

At first glance, the Sun is just a ball made of helium and hydrogen, but upon deeper study it is clear that it consists of different layers. When moving towards the core, temperature and pressure increase, as a result of which layers were created, since under different conditions hydrogen and helium have different characteristics.

solar core

Let's begin our movement through the layers from the core to the outer layer of the Sun's composition. In the inner layer of the Sun - the core, the temperature and pressure are very high, conducive to nuclear fusion. The sun creates helium atoms from hydrogen, as a result of this reaction, light and heat are formed, which reach. It is generally accepted that the temperature on the Sun is about 13,600,000 degrees Kelvin, and the density of the core is 150 times higher than the density of water.

Scientists and astronomers believe that the Sun's core reaches about 20% of the length of the solar radius. And inside the core, high temperature and pressure cause hydrogen atoms to break apart into protons, neutrons and electrons. The sun converts them into helium atoms, despite their free-floating state.

This reaction is called exothermic. When this reaction occurs, a large amount of heat is released, equal to 389 x 10 31 J. per second.

Radiation zone of the Sun

This zone originates at the core boundary (20% of the solar radius), and reaches a length of up to 70% of the solar radius. Inside this zone there is solar matter, which in its composition is quite dense and hot, so thermal radiation passes through it without losing heat.

Nuclear fusion reaction occurs inside the solar core - the creation of helium atoms as a result of the fusion of protons. This reaction produces a large amount of gamma radiation. In this process, photons of energy are emitted, then absorbed in the radiation zone and emitted again by various particles.

The trajectory of a photon is usually called a “random walk.” Instead of moving in a straight path to the surface of the Sun, the photon moves in a zigzag pattern. As a result, each photon takes approximately 200,000 years to overcome the radiation zone of the Sun. When moving from one particle to another particle, the photon loses energy. This is good for the Earth, because we could only receive gamma radiation coming from the Sun. A photon entering space needs 8 minutes to travel to Earth.

A large number of stars have radiation zones, and their sizes directly depend on the scale of the star. How less star, the smaller the zones will be, most of which will be occupied by the convective zone. The smallest stars may lack radiation zones, and the convective zone will reach the distance to the core. At the most big stars the situation is the opposite, the radiation zone extends to the surface.

Convective zone

The convective zone is outside the radiative zone, where the sun's internal heat flows through columns of hot gas.

Almost all stars have such a zone. For our Sun, it extends from 70% of the Sun's radius to the surface (photosphere). The gas in the depths of the star, near the very core, heats up and rises to the surface, like bubbles of wax in a lamp. Upon reaching the surface of the star, heat loss occurs; as it cools, the gas sinks back toward the center, recovering thermal energy. As an example, you can bring a pan of boiling water on fire.

The surface of the Sun is like loose soil. These irregularities are columns of hot gas that carry heat to the surface of the Sun. Their width reaches 1000 km, and the dispersal time reaches 8-20 minutes.

Astronomers believe that low-mass stars, such as red dwarfs, have only a convective zone that extends to the core. They do not have a radiation zone, which cannot be said about the Sun.

Photosphere

The only layer of the Sun visible from Earth is . Below this layer, the Sun becomes opaque, and astronomers use other methods to study the interior of our star. Surface temperatures reach 6000 Kelvin and glow yellow-white, visible from Earth.

The atmosphere of the Sun is located behind the photosphere. The part of the Sun that is visible during a solar eclipse is called.

Structure of the Sun in the diagram

NASA has specially developed for educational needs a schematic representation of the structure and composition of the Sun, indicating the temperature for each layer:

• (Visible, IR and UV radiation) – these are visible radiation, infrared radiation and ultraviolet radiation. Visible radiation is the light that we see coming from the Sun. Infrared radiation is the heat we feel. Ultraviolet radiation is the radiation that gives us a tan. The sun produces these radiations simultaneously.
• (Photosphere 6000 K) – The photosphere is the upper layer of the Sun, its surface. A temperature of 6000 Kelvin is equal to 5700 degrees Celsius.
• Radio emissions - In addition to visible radiation, infrared radiation and ultraviolet radiation, the Sun emits radio emissions, which astronomers have discovered using a radio telescope. Depending on the number of sunspots, this emission increases and decreases.
• Coronal Hole - These are places on the Sun where the corona has a low plasma density, as a result it is darker and colder.
• 2100000 K (2100000 Kelvin) – The radiation zone of the Sun has this temperature.
• Convective zone/Turbulent convection (trans. Convective zone/Turbulent convection) – These are places on the Sun where the thermal energy of the core is transferred by convection. Columns of plasma reach the surface, give up their heat, and again rush down to heat up again.
• Coronal loops (trans. Coronal loops) - loops consisting of plasma in the solar atmosphere, moving along magnetic lines. They look like huge arches extending from the surface for tens of thousands of kilometers.
• Core (trans. Core) is the solar heart in which nuclear fusion occurs using high temperature and pressure. All solar energy comes from the core.
• 14,500,000 K (per. 14,500,000 Kelvin) – Temperature of the solar core.
• Radiative Zone (trans. Radiation zone) - A layer of the Sun where energy is transmitted using radiation. The photon overcomes the radiation zone beyond 200,000 and goes into outer space.
• Neutrinos (trans. Neutrino) are negligibly small particles emanating from the Sun as a result of a nuclear fusion reaction. Hundreds of thousands of neutrinos pass through the human body every second, but they do not cause us any harm, we do not feel them.
• Chromospheric Flare (translated as Chromospheric Flare) - The magnetic field of our star can twist, and then abruptly break into various forms. As a result of breaks in magnetic fields, powerful X-ray flares appear from the surface of the Sun.
• Magnetic Field Loop - The Sun's magnetic field is located above the photosphere, and is visible as hot plasma moves along magnetic lines in the Sun's atmosphere.
• Spot – A sunspot (trans. Sun spots) – These are places on the surface of the Sun where magnetic fields pass through the surface of the Sun, and the temperature is lower, often in the form of a loop.
• Energetic particles (trans. Energetic particles) - They come from the surface of the Sun, resulting in the creation of the solar wind. In solar storms their speed reaches the speed of light.
• X-rays (trans. X-rays) - rays invisible to the human eye, produced during solar flares.
• Bright spots and short-lived magnetic regions (trans. Bright spots and short-lived magnetic regions) - Due to temperature differences, bright and dim spots appear on the surface of the Sun.

Since the thirties, astrophysicists have had no doubt that of the nuclear reactions in light elements, the only one capable of sustaining the radiation of main sequence stars on the spectrum-luminosity diagram for a sufficiently long time and energetically is the formation of helium from hydrogen. Other reactions either last too short a time (on a cosmic scale, of course!) or produce too little energy output.

However, the path of directly combining four hydrogen nuclei into a helium nucleus turned out to be impossible: the reaction of converting hydrogen into helium in the depths of stars must take a “roundabout route.”

The first way consists in the sequential connection of first two hydrogen atoms, then adding a third to them, etc.

The second way is to convert hydrogen into helium with the “help” of nitrogen and especially carbon atoms.

Although the first path seems to be simpler, for quite a long time it did not receive “due respect”, and astrophysicists believed that the main reaction feeding stars with energy was the second path - the “carbon cycle”.

The construction of a helium nucleus requires four protons, which on their own would never want to form into an alpha particle if carbon did not help them.

In the chain of these reactions, carbon plays the role of a necessary accomplice and, as it were, an organizer. IN chemical reactions There are also such accomplices, called catalysts.

When building helium, energy is not only not wasted, but on the contrary, it is released. Indeed, the chain of transformations was accompanied by the release of three γ-quanta and two positrons, which also turned into γ-radiation. The balance is: 10 -5 (4·1.00758-4.00390) =0.02642·10 -5 atomic mass units.

The energy associated with this mass is released in the bowels of the star, seeping slowly to the surface and then radiating into outer space. The helium factory operates continuously in stars until the supply of raw materials, i.e. hydrogen, runs out. We'll tell you what happens next.

Carbon, as a catalyst, will last indefinitely.

At temperatures of the order of 20 million degrees, the action of the carbon cycle reactions is proportional to the 17th power of temperature! At some distance from the center of the star, where the temperature is only 10% lower, energy production drops by 5 times, and where it is one and a half times lower, it drops by 800 times! Therefore, not far from the central, hottest region, the formation of helium due to hydrogen does not occur. The rest of the hydrogen will turn into helium after the mixing of gases brings it into the “factory” territory - to the center of the star.

In the early fifties, it turned out that at a temperature of 20 million degrees, and even more so at more low temperatures The proton-proton reaction is even more effective, also leading to the loss of hydrogen and the formation of helium. Most likely it occurs in such a chain of transformations.

Two protons, colliding, emit a positron and a quantum of light, turning into a heavy isotope of hydrogen with a relative atomic mass 2. The latter, after merging with another proton, turns into an atom of a light isotope of hydrogen with a relative atomic mass of 2. The latter, after merging with another proton, turns into an atom of a light isotope of helium with a relative atomic mass of 3, while emitting excess mass in the form of radiation. If enough such light helium atoms have accumulated, their nuclei upon collision form a normal helium atom with a relative atomic mass of 4 and two protons with an energy quantum in addition. So, in this process three protons were lost and two were created - one proton was lost, but energy was emitted three times.

Apparently, the Sun and cooler main sequence stars in the luminosity-spectrum diagram draw energy from this source.

Once all the hydrogen has been converted to helium, the star can still exist by converting helium into heavier elements. For example, the following processes are possible:

4 2 He + 4 2 He → 8 4 Be + radiation,

4 2 He + 8 4 Be → 12 6 C + radiation.

One helium particle gives an energy output that is 8 times less than what the same particle gives in the carbon cycle described above.

Recently, physicists have found that in some stars the physical conditions allow the emergence of even heavier elements, such as iron, and they calculate the proportion of the resulting elements in accordance with the abundance of elements that we find in nature.

Giant stars have an average energy output per unit of mass that is much greater than that of the Sun. However, there is still no generally accepted point of view on the energy sources in red giant stars. The sources of energy in them and their structure are not yet clear to us, but, apparently, they will soon become known. According to calculations by V.V. Sobolev red giants may have the same structure as hot giants and have the same energy sources. But they are surrounded by vast, thin and cold atmospheres, which give them the appearance of “cold giants.”

The nuclei of some heavy atoms can be formed in the interior of stars by combining lighter atoms, and under some conditions, even in their atmospheres.

Internal structure of stars

We consider a star as a body subject to the action of various forces. The force of gravity tends to pull the matter of the star towards the center, while gas and light pressure, directed from the inside, tend to push it away from the center. Since the star exists as a stable body, it follows that there is some kind of balance between the contending forces. To do this, the temperature of the different layers in the star must be set such that in each layer the outward flow of energy takes all the energy generated underneath it to the surface. Energy is generated in a small central core. For the initial period of a star's life, its compression is a source of energy. But only until the temperature rises so much that nuclear reactions begin.

Formation of stars and galaxies

Matter in the Universe is in continuous development, in a wide variety of forms and states. Since the forms of existence of matter change, then, consequently, different and diverse objects could not all arise at the same time, but were formed in different eras and therefore have their own specific age, counted from the beginning of their origin.

The scientific foundations of cosmogony were laid by Newton, who showed that matter in space under the influence of its own gravity is divided into compressed pieces. The theory of the formation of clumps of matter from which stars are formed was developed in 1902 by the English astrophysicist J. Jeans. This theory also explains the origin of Galaxies. In an initially homogeneous medium with constant temperature and density, compaction may occur. If the force of mutual gravity in it exceeds the force of gas pressure, then the medium will begin to compress, and if gas pressure prevails, then the substance will disperse in space.

It is believed that the age of the Metagalaxy is 13-15 billion years. This age does not contradict the estimates of the age of the oldest stars and globular star clusters in our Galaxy.

Evolution of stars

The condensations that have arisen in the gas and dust environment of the Galaxy, which continue to contract under the influence of their own gravity, are called protostars. As it contracts, the density and temperature of the protostar increases, and it begins to emit abundantly in the infrared range of the spectrum. The duration of compression of protostars is different: for those with a mass less than the Sun - hundreds of millions of years, and for massive ones - only hundreds of thousands of years. When the temperature in the bowels of a protostar rises to several million Kelvin, thermonuclear reactions begin in them, converting hydrogen into helium. In this case, enormous energy is released, preventing further compression and heating the matter to the point of self-luminescence - the protostar turns into an ordinary star. So, the compression stage is replaced by a stationary stage, accompanied by a gradual “burnout” of hydrogen. The star spends most of its life in the stationary stage. It is at this stage of evolution that stars are found that are located on the main “spectrum-luminosity” sequence. The time a star stays on the main sequence is proportional to the mass of the star, since the supply of nuclear fuel depends on this, and inversely proportional to the luminosity, which determines the rate of consumption of nuclear fuel.

When all the hydrogen in the central region is converted to helium, a helium core forms inside the star. Now hydrogen will turn into helium not in the center of the star, but in a layer adjacent to the very hot helium core. As long as there are no energy sources inside the helium core, it will constantly shrink and at the same time heat up even more. Compression of the nucleus leads to a more rapid release of nuclear energy in a thin layer near the boundary of the nucleus. In more massive stars, the temperature of the core during compression becomes above 80 million Kelvin, and thermonuclear reactions begin in it, converting helium into carbon, and then into other heavier chemical elements. The energy escaping from the core and its surroundings causes an increase in gas pressure, under the influence of which the photosphere expands. The energy coming to the photosphere from the interior of the star now spreads over a larger area than before. In this regard, the temperature of the photosphere decreases. The star moves off the main sequence, gradually becoming a red giant or supergiant depending on its mass, and becomes an old star. Passing the yellow supergiant stage, a star may turn out to be a pulsating, that is, a physical variable star, and remain so in the red giant stage. The inflated shell of a star of small mass is already weakly attracted by the core and, gradually moving away from it, forms a planetary nebula. After the final dissipation of the shell, only the hot core of the star remains - a white dwarf.

The fate of more massive stars is different. If the mass of a star is approximately twice the mass of the Sun, then such stars lose stability in the last stages of their evolution. In particular, they can explode as supernovae and then catastrophically shrink to the size of balls with a radius of several kilometers, that is, turn into neutron stars.

A star whose mass is more than twice the mass of the Sun, losing its balance and beginning to contract, will either turn into a neutron star or will not be able to achieve a stable state at all. In the process of unlimited compression, it is likely capable of turning into a black hole.

White dwarfs

White dwarfs are unusual, very small, dense stars with high surface temperatures. home distinguishing feature The internal structure of white dwarfs is gigantic compared to normal density stars. Due to the enormous density, the gas in the interior of white dwarfs is in an unusual state - degenerate. The properties of such a degenerate gas are not at all similar to the properties of ordinary gases. Its pressure, for example, is practically independent of temperature. Sustainability white dwarf is supported by the fact that the enormous force of gravity compressing it is opposed by the pressure of the degenerate gas in its depths.

White dwarfs are at the final stage of evolution of stars of not very large masses. There are no nuclear sources in the star anymore, and it still shines for a very long time, slowly cooling. White dwarfs are stable unless their mass exceeds about 1.4 solar masses.

Neutron stars

Neutron stars are very small, super dense celestial bodies. Their diameter on average is no more than several tens of kilometers. Neutron stars are formed after the exhaustion of sources of thermonuclear energy in the bowels of an ordinary star, if its mass at that moment exceeds 1.4 solar masses. Since there is no source of thermonuclear energy, stable equilibrium of the star becomes impossible and a catastrophic compression of the star towards the center begins - gravitational collapse. If the initial mass of the star does not exceed a certain critical value, then the collapse in the central parts stops and a hot neutron star is formed. The collapse process takes a fraction of a second. It can be followed either by the leakage of the remaining star shell onto a hot neutron star with the emission of neutrinos, or by the release of the shell due to the thermonuclear energy of “unburnt” matter or rotational energy. Such an ejection occurs very quickly and from Earth it looks like a supernova explosion. Observed neutron stars - pulsars - are often associated with supernova remnants. If the mass of a neutron star exceeds 3-5 solar masses, its equilibrium will become impossible, and such a star will be a black hole. Very important characteristics neutron stars- rotation and magnetic field. The magnetic field can be billions to trillions of times stronger than the Earth's magnetic field.