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State Prizes 1971
The average number of works awarded the State Prize in the field of science and technology in 1971 includes three works on various branches of physics and one work on astronomy.
A group of researchers from the Institute of Atomic Energy and the Scientific Research Institute of Electrophysical Equipment named after D. V. Efremov (L. A. Artsimovich, V. D. Shafranov, V. S. Strelkov, D. P. Ivanov, K. A. Razumova, V. S. Mukhovatov, E. P. Gorbunov, S. V. Mironov, A. K. Spiridonov, A. M. Us, M.P. Petrov, N.A. Monoson), headed by Academician L.A. Artsimovich, was awarded a prize for the series of works “Obtaining and studying high-temperature thermonuclear plasma at Tokamak installations.”
Humanity strives for continuous expansion of its energy resources. Along with thermal power plants and hydroelectric power plants, nuclear power plants have recently appeared. They are able to provide a lot of energy for a long period of time. But even richer energy resources are associated with solving problems of controlling thermonuclear reactions.
If we could heat hydrogen to hundreds of millions of degrees and maintain this ultra-high temperature for several minutes, water would turn into an excellent fuel. At high temperatures, the atomic nuclei of nature’s lightest element, hydrogen, would fuse into heavier gel nuclei, releasing enormous amounts of energy. Physicists called this process of fusion of light nuclei a thermonuclear reaction. A thermomodern reaction will occur when a hydrogen bomb explodes. But we cannot control it at the moment of the explosion.
For about a long time now, scientists in many countries have been looking for ways to control the thermonuclear reaction. Soviet physicists made an important contribution to these studies.
At enormous temperatures, hydrogen atoms collide with each other and disintegrate the loaded shards in electricity, forming the so-called plasma. Hot plasma is very capricious and unstable. It easily overcomes all obstacles and instantly gives its energy to the walls of the vessel in which it is enclosed. To isolate the plasma from the walls of the vessel, combinations of magnetic fields are used to limit the movement of loaded particles. However, plasma overcomes these artificial barriers in various ways. Therefore, the lifetime of hot plasma (or, as they say, its lifetime) until recently did not exceed millionths of a second.
10 years ago at the Institute of Atomic Energy and the Scientific Research Institute of Electrophysical Equipment named after D. V. Efremov (L. A. Artsimovich, V. D. Shafranov, V. S. Strelkov, D. P. Ivanov, K. A. Razumova, V. S. Mukhovatov, E. P. Gorbunov, S. V. Mironov, A. K. Spiridonov, A. M. Us, M. P. Petrov, N. A. Monoson), headed by Academician L. A. Artsimovich, was awarded a prize for the series of works “Obtaining and studying high-temperature thermonuclear plasma at Tokamak installations”).
A torid metal chamber in shape fills the animated automatic chamber. The air is routinely switched off from it, after which a small amount of so-called heavy hydrogen is introduced into the chamber. Atoms of action are heavy with living hydrogen atoms.
The chamber covers the core of a powerful transformer connected to a battery of electrical capacitors, the energy of which reaches a million joules. When the capacitors discharge in the chamber, an electrical breakdown of the gas occurs and an electric plasma creates the action. An induction current arises in it. It heats the plasma to a temperature of 5 million degrees. The magnetic field associated with the induced current causes the loaded portion of the plasma to leak out onto the inner wall of the torus. However, the insulating properties of the magnetic field of the induced current are not strong enough, and the hot plasma almost instantly hits the chamber wall.
In Tokamak installations, coils are placed on the damaged surface of the torus, creating a strong pulsed magnetic field, strong and linear, parallel to the walls of the torus. The strength of the additional magnetic field in the chamber reaches 40,000 gauss. This field significantly improves the magnetic isolation of plasma action. The lifetime of hot plasma increases to 0.05 seconds.
During this period, atomic nuclei will collide with each other many times. In this case, atomic nuclei of the gel are formed and free neutrons appear. The thermonuclear reaction occurring in Tokamaks can be written as the following formula:
The gel nuclei formed in this reaction belong to the so-called “light” gel; They are three times the heavy nucleus of living hydrogen.
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In the course of work on the creation and research of Tokamak thermonuclear installations, L. A. Artsimovich and his collaborators built theories describing the behavior of plasma in these installations and developed methods for measuring various characteristics of plasma (temperature of ions and electrons, concentration, lifetime, etc.). Much research has resulted in false results. Experiments have shown that in Tokamak installations it is possible to suppress the influence of all the most dangerous mechanisms of plasma instability. Thanks to this, record lifetimes of hot plasma were obtained. For the first time in the history of science, thermonuclear neutron fluxes have been recorded in laboratory conditions.
The results achieved by Soviet physicists turned out to be so unexpected that many foreign scientists, having learned about them, expressed doubt about their reliability. However, experiments carried out jointly by Soviet and British scientists in 1969 to measure the main characteristics of hot plasma in the Tokamak installation subjected these results.
The study of hot plasma in Tokamak installations became the main direction of work on controlled thermonuclear fusion in the USSR. Similar installations are now being built in the USA, France, Russia, Japan, Italy and other countries. Experts believe that the results achieved by Soviet scientists open up a real prospect of creating thermonuclear power plants based on installations similar to Tokamaks. True, this will require an increase in the temperature, concentration and lifetime of the hot plasma.
The second prize in the section of physics was awarded to a team of researchers from the Institute of Physics and Energy, the Joint Institute for Nuclear Research, the Institute of Atomic Energy initiated by I.V. Kurchatov and the Central Institute of Aviation Engine Engineering named after P.I. Baranov, consisting of D.I. Blozhintsev, I.M. Frank, F.L. Shapiro, I.M. Matori, E.P. Shebalina, S.K. Nikolaev, V. T. Rudenko, F. I. Ukraintseva, I. S. Golovina, G. E. Blozhintsa, I. I. Bondarenko. This team satisfies the State Prize for the creation of a new nuclear reactor - a research pulsed fast neutron reactor (abbreviated as IBR).
Nuclear reactors serve as potential sources of energy. At the same time, they produce a huge number of free neutrons. Neutrons are one of the new means of studying the nature of matter and atomic nuclei. With their help, it is possible, for example, to determine such details of the structure of the crystal lattice that cannot be determined by any other methods.
The flow of neutrons from a nuclear reactor is continuous. But for many studies, on the contrary, the first beams of neutron radiation are needed. The community receives them using a special device called a mechanical sector. Like a camera shutter, the sector allows neutrons to pass through, look for it through a special channel in the reactor containment, only for short periods of time. However, mechanical sectors greatly weaken the neutron flux.
In 1955, a fundamentally new type of nuclear reactor was proposed and calculated at the Institute of Physics and Power Engineering - a pulsed fast neutron reactor. An operational reactor of this type was built in 1960 in Dubna. It is a unique source of powerful existential neutron beams. It is created, figuratively, by the government, tamed by an atomic explosion.
In atomic reactors, a special substance is rapidly slowed down, which slows down the neutrons that form during the fission of heavy nuclei and carry out the whole process. In an atomic bomb, once launched, there is no moderator. There, a chain process is created by fast neutrons.
A nuclear explosive (uranium-235 or plutonium-239) has a so-called critical mass. An explosion becomes possible only after the mass of a piece of explosive exceeds this critical value. Therefore, a bomb contains not one, but two or more pieces of nuclear material. explosive, the mass of each of which is less than the critical mass. However, following this, the chain reaction of nuclear fission is interrupted, since an additional piece of explosive is immediately removed from the reaction zone.
The design of the IBR reactor also. Two flat 239 density Crosbies are spaced a short distance apart. In the gap formed between them is a built-in edge of a steel disk with a diameter of about one meter. A small flat insert made of uranium-235 is pressed into the disk. The disk rotation speed is about 5000 rpm. With each revolution of the disk, it is balanced between the compaction boxes, causing a chain reaction. But after this, the liner is removed from the pluton and the chain process ends. In this way, the IBR creates powerful bursts of neutron radiation lasting several fractions of a second.
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They are separated from each other by a significant majority of time intervals during which no neutrons will be produced.
The neutrons produced in the reactor have significantly different energies. However, a pulsed reactor makes it possible to easily isolate neutrons with a certain energy value, that is, to carry out so-called neutron electrometry. To do this, it is enough to turn on the recording equipment at the moment when neutrons of the energy we need approach it (faster neutrons will pass earlier, slower neutrons will pass later).
To release neutrons with a given energy in Dubna, a 1000-meter metal tube was laid from the IBR reactor to the hall where the experiments are carried out, from which the air was evacuated. The long path length results in the separation of neutrons by energy (near the reactor, neutrons of different energies travel very close to each other), and the labor transforms the scattering of neutrons.
With an average power of about 25 kilowatts, the IBR reactor in many experiments replaces a conventional continuous reactor with a power of up to 100,000 kilowatts, and in some cases up to 1,000,000 kilowatts.
The IBR reactor has carried out valuable research in the field of atomic nuclear physics and solid state physics, which has gained wide international fame.
Problems involving the interaction of several bodies present a huge difficulty for theoretical physics. Such problems are especially difficult in the field of quantum mechanics, where the very nature of interacting particles is much more complex than that of bodies studied by ordinary Newtonian mechanics. Such problems do not have exact solutions, and their approximate solutions require extensive computational work. Leningrad theoretical physicist L.D. Faddeev, in a series of works “Correct formulation and study of the quantum problem of three parts” (“Faddeev’s Equations”), found ways to accurately solve such problems. The method he developed makes it possible to solve many complex problems in the field of atomic and nuclear physics, as well as elementary particle physics. This method is used to calculate such systems as an atom and two electrons interacting with it, three interacting nuclei (prototypes or neutrons), a nucleus and two nuclei of parts interacting with it, etc. Recently, this new method of calculation was able to be extended to the case of interaction of four or more parts. For the successful solution of a whole range of problems in quantum mechanics, L.D. Faddeev was awarded the State Prize.
A group of Soviet astronomers consisting of E. P. Aksenov, V. G. Demin, G. N. Duboshin, E. A. Grebennikov and M. D. Kislik was awarded the State Prize for “a series of works on modern problems and methods of celestial mechanics, published in 1958-1968.”
When solving various problems about the motion of planets and artificial satellites in celestial mechanics, they usually proceed as follows. As a first approximation, the trajectory of the celestial body under study is considered elliptical. Then corrections and clarifications are made related to the influence of various odd stationary objects (or, as astronomers say, disturbances). These include: asymmetry of the central gravitational body (for example, the Earth), the influence of neighboring planets, the gravitation of the Sun, the own rotation of the cosmic body under study, etc. In this case, the initial trajectory of movement is distorted: the ellipse begins to show, rotate in the orbital plane, which, in turn, also changes its spatial orientation. Taking into account disturbances gives a complex trajectory of motion.
However, these approximate methods for calculating the trajectory of celestial objects are suitable only on the condition that disturbances in the state of other objects, as well as deviations in the distance between shapes and the uneven distribution of the masses of their internal ones, are insignificant. They are unable to take into account the interaction between the translational and rotational motion of the distance of bodies. In reality, even when studying the motion of the long-lasting satellites of the Earth and the Moon, it is impossible to calculate their orbits for a long period using methods either extremely difficult or completely impossible. It was not possible to obtain reliable results for the satellites of Mars, Jupiter, the so-called “resonant” astrojudes, comets passing close to Jupiter.
The authors of the award-winning series of works proposed a completely new method for solving such problems. They worked away from Keller’s elliptical orbits and found more non-elliptical orbits, used as a first approximation. The models of the celestial granitic surface he constructed describe the granitic fields of the Earth, Moon and other celestial bodies more accurately than in classical mechanics. The perturbation theory created by the authors allows us to take into account the mutual influence of the simultaneous occurrence of translational and rotational movements of celestial bodies.
Using this theory, it is possible to calculate over long periods of time the exact orbits of artificial satellites of the Earth, taking into account the inhomogeneities of its gravitational field, the disturbing influence of the Moon and the Sun, the light pressure of solar rays and a number of other factors. It was also possible to obtain fairly accurate solutions to the problems of the motion of the satellites of Mars Phobos and Deimos, one of the closest satellites of Jupiter, “resonant” astrojudes, and comets that come close to Jupiter.
V. A. Leshkovce