thermonuclear charge. The difference between a hydrogen bomb and an atomic bomb: a list of differences, the history of creation

The content of the article

H-BOMB, weapons of great destructive power (of the order of megatons in TNT equivalent), the principle of operation of which is based on the reaction of thermonuclear fusion of light nuclei. The energy source of the explosion are processes similar to those occurring on the Sun and other stars.

thermonuclear reactions.

The interior of the Sun contains a gigantic amount of hydrogen, which is in a state of superhigh compression at a temperature of approx. 15,000,000 K. At such a high temperature and plasma density, hydrogen nuclei experience constant collisions with each other, some of which end in their merger and, ultimately, the formation of heavier helium nuclei. Such reactions, called thermonuclear fusion, are accompanied by the release of a huge amount of energy. According to the laws of physics, the energy release during thermonuclear fusion is due to the fact that when a heavier nucleus is formed, part of the mass of the light nuclei included in its composition is converted into a colossal amount of energy. That is why the Sun, having a gigantic mass, loses approx. 100 billion tons of matter and releases energy, thanks to which life on Earth became possible.

Isotopes of hydrogen.

The hydrogen atom is the simplest of all existing atoms. It consists of one proton, which is its nucleus, around which a single electron revolves. Careful studies of water (H 2 O) have shown that it contains a negligible amount of "heavy" water containing the "heavy isotope" of hydrogen - deuterium (2 H). The deuterium nucleus consists of a proton and a neutron, a neutral particle with a mass close to that of a proton.

There is a third isotope of hydrogen, tritium, which contains one proton and two neutrons in its nucleus. Tritium is unstable and undergoes spontaneous radioactive decay, turning into an isotope of helium. Traces of tritium have been found in the Earth's atmosphere, where it is formed as a result of the interaction of cosmic rays with gas molecules that make up the air. Tritium is obtained artificially in a nuclear reactor by irradiating the lithium-6 isotope with a neutron flux.

Development of the hydrogen bomb.

A preliminary theoretical analysis showed that thermonuclear fusion is most easily carried out in a mixture of deuterium and tritium. Taking this as a basis, US scientists in the early 1950s began to implement a project to create a hydrogen bomb (HB). The first tests of a model nuclear device were carried out at the Eniwetok test site in the spring of 1951; thermonuclear fusion was only partial. Significant success was achieved on November 1, 1951, in the testing of a massive nuclear device, the explosion power of which was 4 x 8 Mt in TNT equivalent.

The first hydrogen aerial bomb was detonated in the USSR on August 12, 1953, and on March 1, 1954, the Americans detonated a more powerful (about 15 Mt) aerial bomb on Bikini Atoll. Since then, both powers have been detonating advanced megaton weapons.

The explosion on the Bikini Atoll was accompanied by the release of a large amount of radioactive substances. Some of them fell hundreds of kilometers from the site of the explosion onto the Japanese fishing vessel Lucky Dragon, while others covered the island of Rongelap. Since thermonuclear fusion produces stable helium, the radioactivity in the explosion of a purely hydrogen bomb should be no more than that of an atomic detonator of a thermonuclear reaction. However, in the case under consideration, the predicted and actual radioactive fallout differed significantly in quantity and composition.

The mechanism of action of the hydrogen bomb.

The sequence of processes occurring during the explosion of a hydrogen bomb can be represented as follows. First, the thermonuclear reaction initiator charge (a small atomic bomb) inside the HB shell explodes, resulting in a neutron flash and creating the high temperature necessary to initiate thermonuclear fusion. Neutrons bombard an insert made of lithium deuteride, a compound of deuterium with lithium (a lithium isotope with a mass number of 6 is used). Lithium-6 is split by neutrons into helium and tritium. Thus, the atomic fuse creates the materials necessary for synthesis directly in the bomb itself.

Then a thermonuclear reaction begins in a mixture of deuterium and tritium, the temperature inside the bomb rises rapidly, involving more and more hydrogen in the fusion. With a further increase in temperature, a reaction between deuterium nuclei could begin, which is characteristic of a purely hydrogen bomb. All reactions, of course, proceed so quickly that they are perceived as instantaneous.

Division, synthesis, division (superbomb).

In fact, in the bomb, the sequence of processes described above ends at the stage of the reaction of deuterium with tritium. Further, the bomb designers preferred to use not the fusion of nuclei, but their fission. Fusion of deuterium and tritium nuclei produces helium and fast neutrons, the energy of which is large enough to cause the fission of uranium-238 nuclei (the main isotope of uranium, much cheaper than the uranium-235 used in conventional atomic bombs). Fast neutrons split the atoms of the superbomb's uranium shell. The fission of one ton of uranium creates an energy equivalent to 18 Mt. Energy goes not only to the explosion and the release of heat. Each uranium nucleus is split into two highly radioactive "fragments". Fission products include 36 different chemical elements and nearly 200 radioactive isotopes. All this makes up the radioactive fallout that accompanies the explosions of superbombs.

Due to the unique design and the described mechanism of action, weapons of this type can be made as powerful as desired. It is much cheaper than atomic bombs of the same power.

Consequences of the explosion.

Shock wave and thermal effect.

The direct (primary) impact of a superbomb explosion is threefold. The most obvious of the direct effects is a shock wave of tremendous intensity. The strength of its impact, depending on the power of the bomb, the height of the explosion above the ground and the nature of the terrain, decreases with distance from the epicenter of the explosion. The thermal effect of an explosion is determined by the same factors, but, in addition, it also depends on the transparency of the air - fog sharply reduces the distance at which a thermal flash can cause serious burns.

According to calculations, in the event of an explosion in the atmosphere of a 20-megaton bomb, people will remain alive in 50% of cases if they 1) take refuge in an underground reinforced concrete shelter at a distance of about 8 km from the epicenter of the explosion (EW), 2) are in ordinary urban buildings at a distance of approx. . 15 km from the EW, 3) were in the open at a distance of approx. 20 km from EV. In conditions of poor visibility and at a distance of at least 25 km, if the atmosphere is clear, for people in open areas, the probability of surviving increases rapidly with distance from the epicenter; at a distance of 32 km, its calculated value is more than 90%. The area in which the penetrating radiation that occurs during the explosion causes a lethal outcome is relatively small, even in the case of a high-yield superbomb.

Fire ball.

Depending on the composition and mass of the combustible material involved in the fireball, gigantic self-sustaining firestorms can form, raging for many hours. However, the most dangerous (albeit secondary) consequence of the explosion is radioactive contamination of the environment.

Fallout.

How they are formed.

When a bomb explodes, the resulting fireball is filled with a huge amount of radioactive particles. Usually, these particles are so small that once they get into the upper atmosphere, they can remain there for a long time. But if the fireball comes into contact with the surface of the Earth, everything that is on it, it turns into red-hot dust and ash and draws them into a fiery tornado. In the vortex of flame, they mix and bind with radioactive particles. Radioactive dust, except for the largest, does not settle immediately. Finer dust is carried away by the resulting explosion cloud and gradually falls out as it moves downwind. Right at the site of the explosion, radioactive fallout can be extremely intense - mainly coarse dust settling on the ground. Hundreds of kilometers from the site of the explosion and at longer distances, small, but still visible ash particles fall to the ground. Often they form a snow-like cover, deadly to anyone who happens to be nearby. Even smaller and invisible particles, before they settle on the ground, can wander in the atmosphere for months and even years, going around the globe many times. By the time they fall out, their radioactivity is significantly weakened. The most dangerous is the radiation of strontium-90 with a half-life of 28 years. Its fall is clearly observed throughout the world. Settling on foliage and grass, it enters food chains, including humans. As a consequence of this, noticeable, although not yet dangerous, amounts of strontium-90 have been found in the bones of the inhabitants of most countries. The accumulation of strontium-90 in human bones is very dangerous in the long term, as it leads to the formation of malignant bone tumors.

Prolonged contamination of the area with radioactive fallout.

In the event of hostilities, the use of a hydrogen bomb will lead to immediate radioactive contamination of the territory within a radius of approx. 100 km from the epicenter of the explosion. In the event of a superbomb explosion, an area of tens of thousands of square kilometers will be contaminated. Such a huge area of \u200b\u200bdestruction with a single bomb makes it a completely new type of weapon. Even if the super bomb does not hit the target, i.e. will not hit the object with shock-thermal effects, penetrating radiation and radioactive fallout accompanying the explosion will make the surrounding space uninhabitable. Such precipitation can continue for many days, weeks and even months. Depending on their number, the intensity of radiation can reach deadly levels. A relatively small number of superbombs is enough to completely cover a large country with a layer of radioactive dust deadly to all living things. Thus, the creation of the superbomb marked the beginning of an era when it became possible to render entire continents uninhabitable. Even long after direct exposure to fallout has ceased, the danger posed by the high radiotoxicity of isotopes such as strontium-90 will remain. With food grown on soils contaminated with this isotope, radioactivity will enter the human body.

thermonuclear weapon (H-bomb)- a type of nuclear weapon, the destructive power of which is based on the use of the energy of the reaction of nuclear fusion of light elements into heavier ones (for example, the synthesis of one nucleus of a helium atom from two nuclei of deuterium atoms), in which energy is released.

general description [ | ]

A thermonuclear explosive device can be built using both liquid deuterium and gaseous compressed. But the advent of thermonuclear weapons was made possible only by a variety of lithium hydride, lithium-6 deuteride. This is a compound of the heavy isotope of hydrogen - deuterium and the isotope of lithium with a mass number of 6.

Lithium-6 deuteride is a solid substance that allows you to store deuterium (whose normal state is a gas under normal conditions) under normal conditions, and, in addition, its second component, lithium-6, is a raw material for obtaining the most scarce isotope of hydrogen - tritium. Actually, 6 Li is the only industrial source of tritium:

3 6 L i + 0 1 n → 1 3 H + 2 4 H e + E 1 . (\displaystyle ()_(3)^(6)\mathrm (Li) +()_(0)^(1)n\to ()_(1)^(3)\mathrm (H) +() _(2)^(4)\mathrm (He) +E_(1).)

The same reaction occurs in lithium-6 deuteride in a thermonuclear device when irradiated with fast neutrons; released energy E 1 = 4.784 MeV. The resulting tritium (3 H) then reacts with deuterium, releasing energy E 2 = 17.59 MeV:

1 3 H + 1 2 H → 2 4 H e + 0 1 n + E 2 , (\displaystyle ()_(1)^(3)\mathrm (H) +()_(1)^(2)\ mathrm (H) \to ()_(2)^(4)\mathrm (He) +()_(0)^(1)n+E_(2),)

moreover, a neutron with a kinetic energy of at least 14.1 MeV is formed, which can again initiate the first reaction on another lithium-6 nucleus, or cause fission of heavy uranium or plutonium nuclei in a shell or trigger with the emission of several more fast neutrons.

Early US thermonuclear munitions also used natural lithium deuteride, containing mainly an isotope of lithium with a mass number of 7. It also serves as a source of tritium, but for this, the neutrons participating in the reaction must have an energy of 10 MeV and higher: the reaction n+ 7 Li → 3 H + 4 He + n− 2.467 MeV is endothermic, absorbing energy.

A thermonuclear bomb, operating according to the Teller-Ulam principle, consists of two stages: a trigger and a container with thermonuclear fuel.

The device tested by the US in 1952 was not actually a bomb, but was a laboratory sample, a "3-story house filled with liquid deuterium", made in the form of a special design. Soviet scientists have developed precisely the bomb - a complete device suitable for practical military use.

The largest ever detonated hydrogen bomb is the Soviet 58-megaton "Tsar bomb", detonated on October 30, 1961 at the test site of the Novaya Zemlya archipelago. Nikita Khrushchev subsequently publicly joked that the 100-megaton bomb was originally supposed to be detonated, but the charge was reduced "so as not to break all the windows in Moscow." Structurally, the bomb was indeed designed for 100 megatons, and this power could be achieved by replacing lead with uranium. The bomb was detonated at an altitude of 4,000 meters above the Novaya Zemlya test site. The shock wave after the explosion circled the globe three times. Despite a successful test, the bomb did not enter service; nevertheless, the creation and testing of the superbomb was of great political importance, demonstrating that the USSR had solved the problem of achieving practically any level of megatonnage of a nuclear arsenal.

USA [ | ]

The idea of a fusion bomb initiated by an atomic charge was proposed by Enrico Fermi to his colleague Edward Teller in the autumn of 1941, at the very beginning of the Manhattan Project. Teller spent much of his work on the Manhattan Project working on the fusion bomb project, to some extent neglecting the atomic bomb itself. His focus on difficulties and his "devil's advocate" position in discussions of problems caused Oppenheimer to lead Teller and other "problem" physicists to a siding.

The first important and conceptual steps towards the implementation of the synthesis project were taken by Teller's collaborator Stanislav Ulam. To initiate thermonuclear fusion, Ulam proposed to compress the thermonuclear fuel before it starts heating, using the factors of the primary fission reaction for this, and also to place the thermonuclear charge separately from the primary nuclear component of the bomb. These proposals made it possible to translate the development of thermonuclear weapons into a practical plane. Based on this, Teller suggested that the X-ray and gamma radiation generated by the primary explosion could transfer enough energy to the secondary component, located in a common shell with the primary, to carry out sufficient implosion (compression) and initiate a thermonuclear reaction. Later, Teller, his supporters and detractors discussed Ulam's contribution to the theory behind this mechanism.

Explosion "George"

In 1951, a series of tests was carried out under the general name Operation "Greenhouse" (English Operation Greenhouse), during which the issues of miniaturization of nuclear charges were worked out with an increase in their power. One of the tests in this series was an explosion codenamed "George" (eng. George), in which an experimental device was blown up, which was a nuclear charge in the form of a torus with a small amount of liquid hydrogen placed in the center. The main part of the explosion power was obtained precisely due to hydrogen fusion, which confirmed in practice the general concept of two-stage devices.

"Evie Mike"

Soon the development of thermonuclear weapons in the United States was directed towards the miniaturization of the Teller-Ulam design, which could be equipped with intercontinental ballistic missiles (ICBMs/ICBMs) and submarine-launched ballistic missiles (SLBMs/SLBMs). By 1960, the W47 megaton-class warheads deployed on submarines equipped with Polaris ballistic missiles were adopted. The warheads had a mass of 320 kg and a diameter of 50 cm. Later tests showed the low reliability of the warheads installed on the Polaris missiles, and the need for their improvements. By the mid-1970s, the miniaturization of new versions of the Teller-Ulam warheads made it possible to place 10 or more warheads in the dimensions of the warhead of multiple reentry vehicle (MIRV) missiles.

the USSR [ | ]

North Korea [ | ]

In December of the year, the KCNA released a statement by the leader of the DPRK, Kim Jong-un, in which he reports that Pyongyang has its own hydrogen bomb.

On August 12, 1953, the first Soviet hydrogen bomb was tested at the Semipalatinsk test site.

And on January 16, 1963, at the height of the Cold War, Nikita Khrushchev announced to the world that the Soviet Union possesses new weapons of mass destruction in its arsenal. A year and a half earlier, the most powerful explosion of a hydrogen bomb in the world was carried out in the USSR - a charge with a capacity of over 50 megatons was blown up on Novaya Zemlya. In many ways, it was this statement by the Soviet leader that made the world aware of the threat of a further escalation of the nuclear arms race: already on August 5, 1963, an agreement was signed in Moscow banning nuclear weapons tests in the atmosphere, outer space and under water.

History of creation

The theoretical possibility of obtaining energy by thermonuclear fusion was known even before the Second World War, but it was the war and the subsequent arms race that raised the question of creating a technical device for the practical creation of this reaction. It is known that in Germany in 1944, work was underway to initiate thermonuclear fusion by compressing nuclear fuel using charges of conventional explosives - but they were unsuccessful, since they could not obtain the necessary temperatures and pressures. The USA and the USSR have been developing thermonuclear weapons since the 1940s, having tested the first thermonuclear devices almost simultaneously in the early 1950s. In 1952, on the Enewetok Atoll, the United States carried out an explosion of a charge with a capacity of 10.4 megatons (which is 450 times the power of the bomb dropped on Nagasaki), and in 1953 a device with a capacity of 400 kilotons was tested in the USSR.

The designs of the first thermonuclear devices were ill-suited for real combat use. For example, a device tested by the United States in 1952 was an above-ground structure as high as a 2-story building and weighing over 80 tons. Liquid thermonuclear fuel was stored in it with the help of a huge refrigeration unit. Therefore, in the future, the serial production of thermonuclear weapons was carried out using solid fuel - lithium-6 deuteride. In 1954, the United States tested a device based on it at Bikini Atoll, and in 1955, a new Soviet thermonuclear bomb was tested at the Semipalatinsk test site. In 1957, a hydrogen bomb was tested in the UK. In October 1961, a thermonuclear bomb with a capacity of 58 megatons was detonated in the USSR on Novaya Zemlya - the most powerful bomb ever tested by mankind, which went down in history under the name "Tsar Bomba".

Further development was aimed at reducing the size of the design of hydrogen bombs in order to ensure their delivery to the target by ballistic missiles. Already in the 60s, the mass of devices was reduced to several hundred kilograms, and by the 70s, ballistic missiles could carry more than 10 warheads at the same time - these are missiles with multiple warheads, each of the parts can hit its own target. To date, the United States, Russia and Great Britain have thermonuclear arsenals, tests of thermonuclear charges were also carried out in China (in 1967) and in France (in 1968).

How the hydrogen bomb works

The action of a hydrogen bomb is based on the use of energy released during the reaction of thermonuclear fusion of light nuclei. It is this reaction that takes place in the interiors of stars, where, under the influence of ultrahigh temperatures and gigantic pressure, hydrogen nuclei collide and merge into heavier helium nuclei. During the reaction, part of the mass of hydrogen nuclei is converted into a large amount of energy - thanks to this, stars release a huge amount of energy constantly. Scientists have copied this reaction using hydrogen isotopes - deuterium and tritium, which gave the name "hydrogen bomb". Initially, liquid isotopes of hydrogen were used to produce charges, and later lithium-6 deuteride, a solid compound of deuterium and an isotope of lithium, was used.

Lithium-6 deuteride is the main component of the hydrogen bomb, thermonuclear fuel. It already stores deuterium, and the lithium isotope serves as a raw material for the formation of tritium. To start a fusion reaction, it is necessary to create high temperatures and pressures, as well as to isolate tritium from lithium-6. These conditions are provided as follows.

The shell of the container for thermonuclear fuel is made of uranium-238 and plastic, next to the container is placed a conventional nuclear charge with a capacity of several kilotons - it is called a trigger, or a charge-initiator of a hydrogen bomb. During the explosion of the initiating plutonium charge, under the influence of powerful X-ray radiation, the container shell turns into plasma, shrinking thousands of times, which creates the necessary high pressure and enormous temperature. At the same time, neutrons emitted by plutonium interact with lithium-6, forming tritium. The nuclei of deuterium and tritium interact under the influence of ultra-high temperature and pressure, which leads to a thermonuclear explosion.

If you make several layers of uranium-238 and lithium-6 deuteride, then each of them will add its power to the bomb explosion - that is, such a "puff" allows you to increase the power of the explosion almost unlimitedly. Thanks to this, a hydrogen bomb can be made of almost any power, and it will be much cheaper than a conventional nuclear bomb of the same power.

Our article is devoted to the history of creation and general principles of synthesis of such a device as sometimes called hydrogen. Instead of releasing explosive energy from the fission of nuclei of heavy elements like uranium, it generates even more of it by fusing the nuclei of light elements (like isotopes of hydrogen) into one heavy one (like helium).

Why is nuclear fusion preferable?

In a thermonuclear reaction, which consists in the fusion of the nuclei of the chemical elements involved in it, much more energy is generated per unit mass of a physical device than in a pure atomic bomb that implements a nuclear fission reaction.

In an atomic bomb, fissile nuclear fuel quickly, under the action of the energy of detonation of conventional explosives, is combined in a small spherical volume, where its so-called critical mass is created, and the fission reaction begins. In this case, many of the neutrons released from the fissile nuclei will cause the fission of other nuclei in the fuel mass, which also emit additional neutrons, which leads to a chain reaction. It covers no more than 20% of the fuel before the bomb explodes, or perhaps much less if the conditions are not ideal: for example, in the atomic bombs Baby, dropped on Hiroshima, and Fat Man, which struck Nagasaki, efficiency (if such a term can be applied to them at all) apply) were only 1.38% and 13%, respectively.

The fusion (or fusion) of the nuclei covers the entire mass of the bomb charge and lasts as long as the neutrons can find the thermonuclear fuel that has not yet reacted. Therefore, the mass and explosive power of such a bomb are theoretically unlimited. Such a merger could theoretically continue indefinitely. Indeed, a thermonuclear bomb is one of the potential doomsday devices that could destroy all human life.

What is a nuclear fusion reaction?

The fuel for the fusion reaction is the hydrogen isotope deuterium or tritium. The first differs from ordinary hydrogen in that in its nucleus, in addition to one proton, there is also a neutron, and in the nucleus of tritium there are already two neutrons. In natural water, one atom of deuterium accounts for 7,000 hydrogen atoms, but out of its quantity. contained in a glass of water, it is possible to obtain the same amount of heat as a result of a thermonuclear reaction, as in the combustion of 200 liters of gasoline. In a 1946 meeting with politicians, the father of the American hydrogen bomb, Edward Teller, emphasized that deuterium provides more energy per gram of weight than uranium or plutonium, but costs twenty cents per gram compared to several hundred dollars per gram of fission fuel. Tritium does not occur in nature in a free state at all, therefore it is much more expensive than deuterium, with a market price of tens of thousands of dollars per gram, however, the greatest amount of energy is released precisely in the fusion of deuterium and tritium nuclei, in which the nucleus of a helium atom is formed and released neutron carrying away excess energy of 17.59 MeV

D + T → 4 He + n + 17.59 MeV.

This reaction is shown schematically in the figure below.

Is it a lot or a little? As you know, everything is known in comparison. So, the energy of 1 MeV is about 2.3 million times more than what is released during the combustion of 1 kg of oil. Consequently, the fusion of only two nuclei of deuterium and tritium releases as much energy as is released during the combustion of 2.3∙10 6 ∙17.59 = 40.5∙10 6 kg of oil. But we are talking about only two atoms. You can imagine how high the stakes were in the second half of the 40s of the last century, when work began in the USA and the USSR, the result of which was a thermonuclear bomb.

How it all began

Back in the summer of 1942, at the beginning of the atomic bomb project in the United States (the Manhattan Project) and later in a similar Soviet program, long before a bomb based on uranium fission was built, the attention of some participants in these programs was drawn to a device, which can use a much more powerful thermonuclear fusion reaction. In the United States, the supporter of this approach, and even, one might say, its apologist, was Edward Teller, already mentioned above. In the USSR, this direction was developed by Andrei Sakharov, a future academician and dissident.

For Teller, his fascination with thermonuclear fusion during the years of the creation of the atomic bomb played rather a disservice. As a member of the Manhattan Project, he persistently called for the redirection of funds to implement his own ideas, the purpose of which was a hydrogen and thermonuclear bomb, which did not please the leadership and caused tension in relations. Since at that time the thermonuclear direction of research was not supported, after the creation of the atomic bomb, Teller left the project and took up teaching, as well as research on elementary particles.

However, the outbreak of the Cold War, and most of all the creation and successful testing of the Soviet atomic bomb in 1949, became a new chance for the fierce anti-communist Teller to realize his scientific ideas. He returns to the Los Alamos laboratory, where the atomic bomb was created, and, together with Stanislav Ulam and Cornelius Everett, starts the calculations.

The principle of a thermonuclear bomb

In order to start the nuclear fusion reaction, you need to instantly heat the bomb charge to a temperature of 50 million degrees. The thermonuclear bomb scheme proposed by Teller uses the explosion of a small atomic bomb, which is located inside the hydrogen case. It can be argued that there were three generations in the development of her project in the 40s of the last century:

the Teller variant, known as the "classic super";
more complex, but also more realistic constructions of several concentric spheres;
the final version of the Teller-Ulam design, which is the basis of all thermonuclear weapons systems in operation today.

The thermonuclear bombs of the USSR, at the origins of the creation of which stood Andrei Sakharov, also went through similar design stages. He, apparently, quite independently and independently of the Americans (which cannot be said about the Soviet atomic bomb, created by the joint efforts of scientists and intelligence officers who worked in the United States) went through all of the above design stages.

The first two generations had the property that they had a succession of interlinked "layers", each reinforcing some aspect of the previous one, and in some cases feedback was established. There was no clear division between the primary atomic bomb and the secondary thermonuclear one. In contrast, the Teller-Ulam design of a thermonuclear bomb sharply distinguishes between a primary explosion, a secondary explosion, and, if necessary, an additional one.

The device of a thermonuclear bomb according to the Teller-Ulam principle

Many of its details are still classified, but there is reasonable certainty that all thermonuclear weapons now available use as a prototype a device created by Edward Telleros and Stanislav Ulam, in which an atomic bomb (i.e., a primary charge) is used to generate radiation, compresses and heats fusion fuel. Andrei Sakharov in the Soviet Union apparently independently came up with a similar concept, which he called "the third idea."

Schematically, the device of a thermonuclear bomb in this embodiment is shown in the figure below.

It was cylindrical, with a roughly spherical primary atomic bomb at one end. The secondary thermonuclear charge in the first, still non-industrial samples, was from liquid deuterium, a little later it became solid from a chemical compound called lithium deuteride.

The fact is that lithium hydride LiH has long been used in industry for the balloonless transportation of hydrogen. The developers of the bomb (this idea was first used in the USSR) simply proposed taking its deuterium isotope instead of ordinary hydrogen and combining it with lithium, since it is much easier to make a bomb with a solid thermonuclear charge.

The shape of the secondary charge was a cylinder placed in a container with a lead (or uranium) shell. Between the charges is a shield of neutron protection. The space between the walls of the container with thermonuclear fuel and the body of the bomb is filled with a special plastic, usually Styrofoam. The body of the bomb itself is made of steel or aluminum.

These shapes have changed in recent designs such as the one shown in the figure below.

In it, the primary charge is flattened, like a watermelon or an American football ball, and the secondary charge is spherical. Such shapes fit much more effectively into the internal volume of conical missile warheads.

Thermonuclear explosion sequence

When the primary atomic bomb detonates, then in the first moments of this process, powerful x-ray radiation (neutron flux) is generated, which is partially blocked by the neutron shield, and is reflected from the inner lining of the case surrounding the secondary charge, so that x-rays fall symmetrically on it throughout its entire length. length.

During the initial stages of a fusion reaction, neutrons from an atomic explosion are absorbed by the plastic filler to prevent the fuel from heating up too quickly.

X-rays cause the appearance of initially dense plastic foam, filling the space between the case and the secondary charge, which quickly turns into a plasma state, heating and compressing the secondary charge.

In addition, the X-rays vaporize the surface of the container surrounding the secondary charge. The substance of the container, symmetrically evaporating with respect to this charge, acquires a certain momentum directed from its axis, and the layers of the secondary charge, according to the law of conservation of momentum, receive an impulse directed towards the axis of the device. The principle here is the same as in a rocket, only if we imagine that the rocket fuel is scattered symmetrically from its axis, and the body is compressed inward.

As a result of such compression of thermonuclear fuel, its volume decreases thousands of times, and the temperature reaches the level of the beginning of the nuclear fusion reaction. A thermonuclear bomb explodes. The reaction is accompanied by the formation of tritium nuclei, which merge with the deuterium nuclei that were originally present in the secondary charge.

The first secondary charges were built around a rod core of plutonium, informally called a "candle", which entered into a nuclear fission reaction, that is, another, additional atomic explosion was carried out in order to raise the temperature even more to ensure the start of the nuclear fusion reaction. It is now believed that more efficient compression systems have eliminated the "candle", allowing further miniaturization of the bomb design.

Operation Ivy

That was the name given to the tests of American thermonuclear weapons in the Marshall Islands in 1952, during which the first thermonuclear bomb was detonated. It was called Ivy Mike and was built according to the typical Teller-Ulam scheme. Its secondary thermonuclear charge was placed in a cylindrical container, which is a thermally insulated Dewar vessel with thermonuclear fuel in the form of liquid deuterium, along the axis of which a "candle" of 239-plutonium passed. The dewar, in turn, was covered with a layer of 238-uranium weighing more than 5 metric tons, which evaporated during the explosion, providing a symmetrical compression of the fusion fuel. The container with primary and secondary charges was placed in a steel case 80 inches wide and 244 inches long with walls 10-12 inches thick, which was the largest example of a wrought product up to that time. The inner surface of the case was lined with sheets of lead and polyethylene to reflect radiation after the explosion of the primary charge and create a plasma that heats up the secondary charge. The entire device weighed 82 tons. A view of the device shortly before the explosion is shown in the photo below.

The first test of a thermonuclear bomb took place on October 31, 1952. The power of the explosion was 10.4 megatons. Attol Eniwetok, on which it was produced, was completely destroyed. The moment of the explosion is shown in the photo below.

USSR gives a symmetrical answer

The US thermonuclear primacy did not last long. On August 12, 1953, the first Soviet thermonuclear bomb RDS-6, developed under the leadership of Andrei Sakharov and Yuli Khariton, was tested at the Semipalatinsk test site. but rather a laboratory device, cumbersome and highly imperfect. Soviet scientists, despite the low power of only 400 kg, tested a completely finished ammunition with thermonuclear fuel in the form of solid lithium deuteride, and not liquid deuterium, like the Americans. By the way, it should be noted that only the 6 Li isotope is used in the composition of lithium deuteride (this is due to the peculiarities of the passage of thermonuclear reactions), and in nature it is mixed with the 7 Li isotope. Therefore, special facilities were built for the separation of lithium isotopes and the selection of only 6 Li.

Reaching power limit

This was followed by a decade of uninterrupted arms race, during which the power of thermonuclear munitions continuously increased. Finally, on October 30, 1961, the most powerful thermonuclear bomb that had ever been built and tested, known in the West as the Tsar Bomba, was detonated in the air at an altitude of about 4 km in the USSR over the Novaya Zemlya test site.

This three-stage munition was actually developed as a 101.5-megaton bomb, but the desire to reduce the radioactive contamination of the territory forced the developers to abandon the third stage with a capacity of 50 megatons and reduce the estimated yield of the device to 51.5 megatons. At the same time, 1.5 megatons was the explosion power of the primary atomic charge, and the second thermonuclear stage was supposed to give another 50. The actual explosion power was up to 58 megatons. The appearance of the bomb is shown in the photo below.

Its consequences were impressive. Despite the very significant explosion height of 4000 m, the incredibly bright fireball almost reached the Earth with its lower edge, and rose to a height of more than 4.5 km with its upper edge. The pressure below the burst point was six times the peak pressure at the Hiroshima explosion. The flash of light was so bright that it could be seen at a distance of 1000 kilometers, despite the cloudy weather. One of the test participants saw a bright flash through dark glasses and felt the effects of a thermal pulse even at a distance of 270 km. A photo of the moment of the explosion is shown below.

At the same time, it was shown that the power of a thermonuclear charge really has no limits. After all, it was enough to complete the third stage, and the design capacity would have been achieved. But you can increase the number of steps further, since the weight of the Tsar Bomba was no more than 27 tons. The view of this device is shown in the photo below.

After these tests, it became clear to many politicians and military men both in the USSR and in the USA that the nuclear arms race had reached its limit and that it had to be stopped.

Modern Russia has inherited the nuclear arsenal of the USSR. Today, Russia's thermonuclear bombs continue to serve as a deterrent to those seeking world hegemony. Let's hope they only play their role as a deterrent and never get blown up.

The sun as a fusion reactor

It is well known that the temperature of the Sun, more precisely its core, reaching 15,000,000 °K, is maintained due to the continuous flow of thermonuclear reactions. However, everything that we could learn from the previous text speaks of the explosive nature of such processes. Then why doesn't the sun explode like a thermonuclear bomb?

The fact is that with a huge proportion of hydrogen in the composition of the solar mass, which reaches 71%, the proportion of its deuterium isotope, the nuclei of which can only participate in the thermonuclear fusion reaction, is negligible. The fact is that deuterium nuclei themselves are formed as a result of the fusion of two hydrogen nuclei, and not just a fusion, but with the decay of one of the protons into a neutron, positron and neutrino (the so-called beta decay), which is a rare event. In this case, the resulting deuterium nuclei are distributed fairly evenly over the volume of the solar core. Therefore, with its huge size and mass, individual and rare centers of thermonuclear reactions of relatively low power are, as it were, spread over the entire core of the Sun. The heat released during these reactions is clearly not enough to instantly burn out all the deuterium in the Sun, but it is enough to heat it up to a temperature that ensures life on Earth.

HYDROGEN BOMB, a weapon of great destructive power (of the order of megatons in TNT equivalent), the principle of operation of which is based on the thermonuclear fusion reaction of light nuclei. The energy source of the explosion are processes similar to those occurring on the Sun and other stars.

In 1961, the most powerful explosion of the hydrogen bomb took place.

On the morning of October 30 at 11:32 a.m. a hydrogen bomb with a capacity of 50 million tons of TNT was detonated over Novaya Zemlya in the region of Mityushi Bay at an altitude of 4000 m above the land surface.

The Soviet Union tested the most powerful thermonuclear device in history. Even in the "half" version (and the maximum power of such a bomb is 100 megatons), the energy of the explosion was ten times higher than the total power of all explosives used by all warring parties during the Second World War (including the atomic bombs dropped on Hiroshima and Nagasaki). The shock wave from the explosion circled the globe three times, the first time in 36 hours and 27 minutes.

The flash of light was so bright that, despite the continuous cloudiness, it was visible even from the command post in the village of Belushya Guba (almost 200 km away from the epicenter of the explosion). The mushroom cloud rose to a height of 67 km. By the time of the explosion, while the bomb was slowly descending on a huge parachute from a height of 10500 to the calculated point of detonation, the Tu-95 carrier aircraft with the crew and its commander, Major Andrei Yegorovich Durnovtsev, was already in the safe zone. The commander returned to his airfield as a lieutenant colonel, Hero of the Soviet Union. In an abandoned village - 400 km from the epicenter - wooden houses were destroyed, and stone houses lost their roofs, windows and doors. For many hundreds of kilometers from the test site, as a result of the explosion, the conditions for the passage of radio waves changed for almost an hour, and radio communications ceased.

The bomb was designed by V.B. Adamsky, Yu.N. Smirnov, A.D. Sakharov, Yu.N. Babaev and Yu.A. Trutnev (for which Sakharov was awarded the third medal of the Hero of Socialist Labor). The mass of the "device" was 26 tons; a specially modified Tu-95 strategic bomber was used to transport and drop it.

The "superbomb", as A. Sakharov called it, did not fit in the aircraft's bomb bay (its length was 8 meters and its diameter was about 2 meters), so the non-power part of the fuselage was cut out and a special lifting mechanism and a device for attaching the bomb were mounted; while in flight, it still sticks out more than half. The entire body of the aircraft, even the blades of its propellers, was covered with a special white paint that protects against a flash of light during an explosion. The body of the accompanying laboratory aircraft was covered with the same paint.

The results of the explosion of the charge, which received the name "Tsar Bomba" in the West, were impressive:

* The nuclear "mushroom" of the explosion rose to a height of 64 km; the diameter of its cap reached 40 kilometers.

The explosion fireball hit the ground and almost reached the bomb release height (i.e., the radius of the explosion fireball was approximately 4.5 kilometers).

* The radiation caused third-degree burns at a distance of up to one hundred kilometers.

* At the peak of the emission of radiation, the explosion reached a power of 1% of the solar one.

* The shock wave resulting from the explosion circled the globe three times.

* Atmospheric ionization has caused radio interference even hundreds of kilometers from the test site for one hour.

* Witnesses felt the impact and were able to describe the explosion at a distance of a thousand kilometers from the epicenter. Also, the shock wave to some extent retained its destructive power at a distance of thousands of kilometers from the epicenter.

* The acoustic wave reached the island of Dixon, where the blast wave knocked out the windows in the houses.

The political result of this test was the demonstration by the Soviet Union of possession of an unlimited power weapon of mass destruction - the maximum megatonnage of a bomb from the United States tested by that time was four times less than that of the Tsar Bomba. Indeed, an increase in the power of a hydrogen bomb is achieved simply by increasing the mass of the working material, so that, in principle, there are no factors preventing the creation of a 100-megaton or 500-megaton hydrogen bomb. (In fact, the Tsar Bomba was designed for a 100-megaton equivalent; the planned explosion power was cut in half, according to Khrushchev, "So as not to break all the glass in Moscow"). With this test, the Soviet Union demonstrated the ability to create a hydrogen bomb of any power and a means of delivering the bomb to the detonation point.

thermonuclear reactions. The interior of the Sun contains a gigantic amount of hydrogen, which is in a state of superhigh compression at a temperature of approx. 15,000,000 K. At such a high temperature and plasma density, hydrogen nuclei experience constant collisions with each other, some of which end in their merger and, ultimately, the formation of heavier helium nuclei. Such reactions, called thermonuclear fusion, are accompanied by the release of a huge amount of energy. According to the laws of physics, the energy release during thermonuclear fusion is due to the fact that when a heavier nucleus is formed, part of the mass of the light nuclei included in its composition is converted into a colossal amount of energy. That is why the Sun, having a gigantic mass, loses approx. 100 billion tons of matter and releases energy, thanks to which life on Earth became possible.

Isotopes of hydrogen. The hydrogen atom is the simplest of all existing atoms. It consists of one proton, which is its nucleus, around which a single electron revolves. Careful studies of water (H 2 O) have shown that it contains negligible amounts of "heavy" water containing the "heavy isotope" of hydrogen - deuterium (2 H). The deuterium nucleus consists of a proton and a neutron, a neutral particle with a mass close to that of a proton.

Development of the hydrogen bomb. A preliminary theoretical analysis showed that thermonuclear fusion is most easily carried out in a mixture of deuterium and tritium. Taking this as a basis, US scientists in the early 1950s began to implement a project to create a hydrogen bomb (HB). The first tests of a model nuclear device were carried out at the Eniwetok test site in the spring of 1951; thermonuclear fusion was only partial. Significant success was achieved on November 1, 1951, when testing a massive nuclear device, the explosion power of which was 4? 8 Mt in TNT equivalent.

The mechanism of action of the hydrogen bomb. The sequence of processes occurring during the explosion of a hydrogen bomb can be represented as follows. First, the thermonuclear reaction initiator charge (a small atomic bomb) inside the HB shell explodes, resulting in a neutron flash and creating the high temperature necessary to initiate thermonuclear fusion. Neutrons bombard an insert made of lithium deuteride - a compound of deuterium with lithium (a lithium isotope with a mass number of 6 is used). Lithium-6 is split by neutrons into helium and tritium. Thus, the atomic fuse creates the materials necessary for synthesis directly in the bomb itself.

Division, synthesis, division (superbomb). In fact, in the bomb, the sequence of processes described above ends at the stage of the reaction of deuterium with tritium. Further, the bomb designers preferred to use not the fusion of nuclei, but their fission. Fusion of deuterium and tritium nuclei produces helium and fast neutrons, the energy of which is large enough to cause the fission of uranium-238 nuclei (the main isotope of uranium, much cheaper than the uranium-235 used in conventional atomic bombs). Fast neutrons split the atoms of the superbomb's uranium shell. The fission of one ton of uranium creates an energy equivalent to 18 Mt. Energy goes not only to the explosion and the release of heat. Each uranium nucleus is split into two highly radioactive "fragments". Fission products include 36 different chemical elements and nearly 200 radioactive isotopes. All this makes up the radioactive fallout that accompanies the explosions of superbombs.