H-bomb. Destroy the world? Thermonuclear bomb: history and myths The principle of operation of a hydrogen bomb for dummies
The atomic bomb and hydrogen bomb are powerful weapons that use nuclear reactions as a source of explosive energy. Scientists first developed nuclear weapons technology during World War II.
Atomic bombs have only been used twice in actual war, both times by the United States against Japan at the end of World War II. The war was followed by a period of nuclear proliferation, and during the Cold War, the United States and the Soviet Union battled for dominance in the global nuclear arms race.
What is a hydrogen bomb, how does it work, the principle of operation of a thermonuclear charge and when were the first tests carried out in the USSR - is written below.
How does an atomic bomb work?
After German physicists Otto Hahn, Lise Meitner and Fritz Strassmann discovered the phenomenon of nuclear fission in Berlin in 1938, the possibility of creating weapons of extraordinary power arose.
When an atom of radioactive material splits into lighter atoms, there is a sudden, powerful release of energy.
The discovery of nuclear fission opened up the possibility of using nuclear technology, including weapons.
An atomic bomb is a weapon that derives its explosive energy only from a fission reaction.
The operating principle of a hydrogen bomb or thermonuclear charge is based on a combination of nuclear fission and nuclear fusion.
Nuclear fusion is another type of reaction in which lighter atoms combine to release energy. For example, as a result of a nuclear fusion reaction, a helium atom is formed from deuterium and tritium atoms, releasing energy.
Manhattan Project
The Manhattan Project was the code name for the American project to develop a practical atomic bomb during World War II. The Manhattan Project was started as a response to the efforts of German scientists who had been working on weapons using nuclear technology since the 1930s.
On December 28, 1942, President Franklin Roosevelt authorized the creation of the Manhattan Project to bring together various scientists and military officials working on nuclear research.
Much of the work was done at Los Alamos, New Mexico, under the direction of theoretical physicist J. Robert Oppenheimer.
On July 16, 1945, in a remote desert location near Alamogordo, New Mexico, the first atomic bomb, equivalent in power to 20 kilotons of TNT, was successfully tested. The explosion of the hydrogen bomb created a huge mushroom-shaped cloud about 150 meters high and ushered in the atomic age.
The only photo of the world's first atomic explosion, taken by American physicist Jack Aebi Baby and Fat Man
Scientists at Los Alamos had developed two different types of atomic bombs by 1945—a uranium-based weapon called "Baby" and a plutonium-based weapon called "Fat Man."
While the war in Europe ended in April, fighting in the Pacific continued between Japanese and US forces.
In late July, President Harry Truman called for Japan's surrender in the Potsdam Declaration. The declaration promised "swift and complete destruction" if Japan did not surrender.
On August 6, 1945, the United States dropped its first atomic bomb from a B-29 bomber called the Enola Gay on the Japanese city of Hiroshima.
The explosion of "Baby" corresponded to 13 kilotons of TNT, leveled five square miles of the city and instantly killed 80,000 people. Tens of thousands of people would later die from radiation exposure.
The Japanese continued to fight, and the United States dropped a second atomic bomb three days later on the city of Nagasaki. The Fat Man explosion killed about 40,000 people.
Citing the destructive power of the "new and most brutal bomb", Japanese Emperor Hirohito announced his country's surrender on August 15, ending World War II.
Cold War
In the post-war years, the United States was the only country with nuclear weapons. At first, the USSR did not have enough scientific developments and raw materials to create nuclear warheads.
But, thanks to the efforts of Soviet scientists, intelligence data and the discovery of regional sources of uranium in Eastern Europe, on August 29, 1949, the USSR tested its first nuclear bomb. The hydrogen bomb device was developed by Academician Sakharov.
From atomic weapons to thermonuclear weapons
The United States responded in 1950 by launching a program to develop more advanced thermonuclear weapons. The Cold War arms race began, and nuclear testing and research became large-scale targets for several countries, especially the United States and the Soviet Union.
this year, the United States detonated a thermonuclear bomb with a yield of 10 megatons of TNT
1955 - The USSR responded with its first thermonuclear test - only 1.6 megatons. But the main successes of the Soviet military-industrial complex were ahead. In 1958 alone, the USSR tested 36 nuclear bombs of various classes. But nothing the Soviet Union experienced compares to the Tsar Bomb.
Test and first explosion of a hydrogen bomb in the USSR
On the morning of October 30, 1961, a Soviet Tu-95 bomber took off from Olenya airfield on the Kola Peninsula in the far north of Russia.
The plane was a specially modified version that had entered service several years ago - a huge four-engine monster tasked with carrying the Soviet nuclear arsenal.
Modified version of the TU-95 "Bear", specially prepared for the first test of the hydrogen Tsar Bomb in the USSR The Tu-95 carried a huge 58-megaton bomb, a device too large to fit inside the aircraft's bomb bay, where such munitions were typically carried. The 8 m long bomb had a diameter of about 2.6 m and weighed more than 27 tons and remained in history with the name Tsar Bomba - “Tsar Bomba”.
The Tsar Bomba was not an ordinary nuclear bomb. It was the result of intense efforts by Soviet scientists to create the most powerful nuclear weapons.
Tupolev reached his target point - Novaya Zemlya, a sparsely populated archipelago in the Barents Sea, above the frozen northern edges of the USSR.
The Tsar Bomba exploded at 11:32 Moscow time. The results of testing a hydrogen bomb in the USSR demonstrated the entire range of damaging factors of this type of weapon. Before answering the question of what is more powerful, an atomic or a hydrogen bomb, you should know that the power of the latter is measured in megatons, while for atomic bombs it is measured in kilotons.
Light radiation
In the blink of an eye, the bomb created a fireball seven kilometers wide. The fireball pulsed from the force of its own shock wave. The flash could be seen thousands of kilometers away - in Alaska, Siberia and Northern Europe.
Shock wave
The consequences of the hydrogen bomb explosion on Novaya Zemlya were catastrophic. In the village of Severny, about 55 km from Ground Zero, all houses were completely destroyed. It was reported that on Soviet territory, hundreds of kilometers from the explosion zone, everything was damaged - houses were destroyed, roofs fell, doors were damaged, windows were destroyed.
The range of a hydrogen bomb is several hundred kilometers.
Depending on the charge power and damaging factors.
The sensors recorded the blast wave as it circled the Earth not once, not twice, but three times. The sound wave was recorded near Dikson Island at a distance of about 800 km.
Electromagnetic pulse
Radio communication throughout the Arctic was disrupted for more than an hour.
Penetrating radiation
The crew received a certain dose of radiation.
Radioactive contamination of the area
The explosion of the Tsar Bomba on Novaya Zemlya turned out to be surprisingly “clean”. The testers arrived at the explosion point two hours later. The radiation level in this place did not pose a great danger - no more than 1 mR/hour within a radius of only 2-3 km. The reasons were the design features of the bomb and the explosion at a sufficiently large distance from the surface.
Thermal radiation
Despite the fact that the carrier aircraft, coated with a special light- and heat-reflecting paint, went 45 km away at the moment the bomb exploded, it returned to base with significant thermal damage to the skin. In an unprotected person, the radiation would cause third-degree burns at a distance of up to 100 km.
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The mushroom after the explosion is visible at a distance of 160 km, the diameter of the cloud at the time of shooting is 56 km |
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Flash from the explosion of the Tsar Bomba, about 8 km in diameter |
The principle of operation of a hydrogen bomb
Hydrogen bomb device. The primary stage acts as a switch - trigger. The plutonium fission reaction in the trigger initiates a thermonuclear fusion reaction in the secondary stage, at which the temperature inside the bomb instantly reaches 300 million °C. A thermonuclear explosion occurs. The first test of a hydrogen bomb shocked the world community with its destructive power.
Video of an explosion at a nuclear test site
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 hydrogen bomb explosion in the world was carried out in the USSR - a charge with a capacity of over 50 megatons was detonated on Novaya Zemlya. In many ways, it was this statement by the Soviet leader that made the world realize the threat of 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 World War II, 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 carried out to initiate thermonuclear fusion by compressing nuclear fuel using charges of conventional explosives - but they were not successful, since it was not possible to obtain the required temperatures and pressures. The USA and the USSR have been developing thermonuclear weapons since the 40s, almost simultaneously testing the first thermonuclear devices in the early 50s. In 1952, the United States exploded a charge with a yield of 10.4 megatons on the Eniwetak Atoll (which is 450 times more powerful than the bomb dropped on Nagasaki), and in 1953, the USSR tested a device with a yield of 400 kilotons.
The designs of the first thermonuclear devices were poorly suited for actual combat use. For example, the device tested by the United States in 1952 was a ground-based structure the height of a 2-story building and weighing over 80 tons. Liquid thermonuclear fuel was stored in it using a huge refrigeration unit. Therefore, in the future, 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, tests of a hydrogen bomb were carried out in Great Britain. 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 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 over 10 warheads at the same time - these are missiles with multiple warheads, each part can hit its own target. Today, the USA, Russia and Great Britain have thermonuclear arsenals; tests of thermonuclear charges were also carried out in China (in 1967) and in France (in 1968).
The principle of operation of a hydrogen bomb
The action of a hydrogen bomb is based on the use of energy released during the thermonuclear fusion reaction of light nuclei. It is this reaction that takes place in the depths of stars, where, under the influence of ultra-high temperatures and enormous 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 constantly release huge amounts of energy. Scientists copied this reaction using hydrogen isotopes deuterium and tritium, giving it 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 the raw material for the formation of tritium. To start a thermonuclear fusion reaction, it is necessary to create high temperatures and pressures, as well as to separate 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, and a conventional nuclear charge with a power of several kilotons is placed next to the container - it is called a trigger, or initiator charge of a hydrogen bomb. During the explosion of the plutonium initiator charge under the influence of powerful X-ray radiation, the shell of the container turns into plasma, compressing 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. Deuterium and tritium nuclei 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 own power to the explosion of a bomb - 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.
H-BOMB
a weapon of great destructive power (on the order of megatons in TNT equivalent), the operating principle of which is based on the reaction of thermonuclear fusion of light nuclei. The source of explosion energy is 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 ultra-high compression at a temperature of approx. 15,000,000 K. At such high temperatures and plasma densities, hydrogen nuclei experience constant collisions with each other, some of which result in their fusion and ultimately the formation of heavier helium nuclei. Such reactions, called thermonuclear fusion, are accompanied by the release of enormous amounts of energy. According to the laws of physics, the energy release during thermonuclear fusion is due to the fact that during the formation of a heavier nucleus, 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. every day in the process of thermonuclear fusion. 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 rotates. Careful studies of water (H2O) have shown that it contains negligible amounts of “heavy” water containing the “heavy isotope” of hydrogen - deuterium (2H). The deuterium nucleus consists of a proton and a neutron - a neutral particle with a mass close to a proton. There is a third isotope of hydrogen - tritium, whose nucleus contains one proton and two neutrons. 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 produced artificially in a nuclear reactor by irradiating the lithium-6 isotope with a stream of neutrons.
Development of the hydrogen bomb. Preliminary theoretical analysis has shown that thermonuclear fusion is most easily accomplished in a mixture of deuterium and tritium.
Taking this as a basis, US scientists at the beginning of 1950 began implementing a project to create a hydrogen bomb (HB). The first tests of a model nuclear device were carried out at the Enewetak test site in the spring of 1951; thermonuclear fusion was only partial. Significant success was achieved on November 1, 1951 during the testing of a massive nuclear device, the explosion power of which was 4e8 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 (approximately 15 Mt) aerial bomb on Bikini Atoll. Since then, both powers have carried out explosions of advanced megaton weapons. The explosion at Bikini Atoll was accompanied by the release of large amounts of radioactive substances. Some of them fell hundreds of kilometers from the explosion site on the Japanese fishing vessel Lucky Dragon, while others covered the island of Rongelap. Since thermonuclear fusion produces stable helium, the radioactivity from the explosion of a pure 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 a 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) located inside the NB 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 mass number 6 is used). Lithium-6 is split into helium and tritium under the influence of neutrons. Thus, the atomic fuse creates the materials necessary for synthesis directly in the actual bomb itself. Then a thermonuclear reaction begins in a mixture of deuterium and tritium, the temperature inside the bomb rapidly increases, involving more and more hydrogen in the synthesis. With a further increase in temperature, a reaction between deuterium nuclei, characteristic of a pure hydrogen bomb, could begin. All reactions, of course, occur so quickly that they are perceived as instantaneous. In fact, in a bomb, the sequence of processes described above ends at the stage of the reaction of deuterium with tritium. Further, the bomb designers chose not to use nuclear fusion, but nuclear fission. The fusion of deuterium and tritium nuclei produces helium and fast neutrons, the energy of which is high enough to cause nuclear fission of uranium-238 (the main isotope of uranium, much cheaper than the uranium-235 used in conventional atomic bombs). Fast neutrons split the atoms of the uranium shell of the superbomb. The fission of one ton of uranium creates energy equivalent to 18 Mt. Energy goes not only to explosion and heat generation. Each uranium nucleus splits into two highly radioactive "fragments". Fission products include 36 different chemical elements and nearly 200 radioactive isotopes. All this constitutes the radioactive fallout that accompanies superbomb explosions. Thanks 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 direct impact is a shock wave of enormous intensity. The strength of its impact, depending on the power of the bomb, the height of the explosion above the surface of the earth and the nature of the terrain, decreases with distance from the epicenter of the explosion. The thermal impact of an explosion is determined by the same factors, but 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, during 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 approximately 8 km from the epicenter of the explosion (E), 2) are in ordinary urban buildings at a distance of approx. . 15 km from EV, 3) found themselves in an open place 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 likelihood of survival increases rapidly with distance from the epicenter; at a distance of 32 km its calculated value is more than 90%. The area over which the penetrating radiation generated during an explosion causes death is relatively small, even in the case of a high-power superbomb.
Fire ball. Depending on the composition and mass of flammable material involved in the fireball, giant self-sustaining firestorms can form and rage 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. Typically, these particles are so small that once they reach the upper atmosphere, they can remain there for a long time. But if a fireball comes into contact with the surface of the Earth, it turns everything on it into hot dust and ash and draws them into a fiery tornado. In a whirlwind of flame, they mix and bind with radioactive particles. Radioactive dust, except the largest, does not settle immediately. Finer dust is carried away by the resulting cloud and gradually falls out as it moves with the wind. Directly at the site of the explosion, radioactive fallout can be extremely intense - mainly large dust settling on the ground. Hundreds of kilometers from the explosion site and at greater distances, small but still visible particles of ash fall to the ground. They often form a cover similar to fallen snow, 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, circling the globe many times. By the time they fall out, their radioactivity is significantly weakened. The most dangerous radiation remains strontium-90 with a half-life of 28 years. Its loss is clearly observed throughout the world. When it settles on leaves and grass, it enters food chains that include humans. As a consequence of this, noticeable, although not yet dangerous, amounts of strontium-90 have been found in the bones of residents 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.
Long-term 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 an area within a radius of approx. 100 km from the epicenter of the explosion. If a superbomb explodes, an area of tens of thousands of square kilometers will be contaminated. Such a huge area of destruction with a single bomb makes it a completely new type of weapon. Even if the superbomb does not hit the target, i.e. will not hit the object with shock-thermal effects, the 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 quantity, 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 that is deadly to all living things. Thus, the creation of the superbomb marked the beginning of an era when it became possible to make entire continents uninhabitable. Even long after the cessation of direct exposure to radioactive fallout, the danger due to 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.
see also
NUCLEAR fusion;
NUCLEAR WEAPON ;
NUCLEAR WAR.
LITERATURE
Effect of nuclear weapons. M., 1960 Nuclear explosion in space, on earth and underground. M., 1970
Collier's Encyclopedia. - Open Society. 2000 .
See what a “HYDROGEN BOMB” is in other dictionaries:
An outdated name for a nuclear bomb of great destructive power, the action of which is based on the use of energy released during the fusion reaction of light nuclei (see Thermonuclear reactions). The first hydrogen bomb was tested in the USSR (1953) ... Big Encyclopedic Dictionary
Thermonuclear weapon is a type of weapon of mass destruction, 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 two nuclei of deuterium (heavy hydrogen) atoms into one ... ... Wikipedia
A nuclear bomb of great destructive power, the action of which is based on the use of energy released during the fusion reaction of light nuclei (see Thermonuclear reactions). The first thermonuclear charge (3 Mt power) was detonated on November 1, 1952 in the USA.… … encyclopedic Dictionary
H-bomb- vandenilinė bomba statusas T sritis chemija apibrėžtis Termobranduolinė bomba, kurios užtaisas – deuteris ir tritis. atitikmenys: engl. Hbomb; hydrogen bomb rus. hydrogen bomb ryšiai: sinonimas – H bomba… Chemijos terminų aiškinamasis žodynas
H-bomb- vandenilinė bomba statusas T sritis fizika atitikmenys: engl. hydrogen bomb vok. Wasserstoffbombe, f rus. hydrogen bomb, f pranc. bombe à hydrogène, f … Fizikos terminų žodynas
H-bomb- vandenilinė bomba statusas T sritis ekologija ir aplinkotyra apibrėžtis Bomba, kurios branduolinis užtaisas – vandenilio izotopai: deuteris ir tritis. atitikmenys: engl. Hbomb; hydrogen bomb vok. Wasserstoffbombe, f rus. hydrogen bomb, f... Ekologijos terminų aiškinamasis žodynas
An explosive bomb with great destructive power. Action V. b. based on thermonuclear reaction. See Nuclear weapons... Great Soviet Encyclopedia
Many of our readers associate the hydrogen bomb with an atomic one, only much more powerful. In fact, this is a fundamentally new weapon, which required disproportionately large intellectual efforts for its creation and works on fundamentally different physical principles.
Editorial Board PM
"Puff"
Modern bomb
The only thing that the atomic and hydrogen bombs have in common is that both release colossal energy hidden in the atomic nucleus. This can be done in two ways: to divide heavy nuclei, for example, uranium or plutonium, into lighter ones (fission reaction) or to force the lightest isotopes of hydrogen to merge (fusion reaction). As a result of both reactions, the mass of the resulting material is always less than the mass of the original atoms. But mass cannot disappear without a trace - it turns into energy according to Einstein’s famous formula E=mc2.
A-bomb
To create an atomic bomb, a necessary and sufficient condition is to obtain fissile material in sufficient quantities. The work is quite labor-intensive, but low-intellectual, lying closer to the mining industry than to high science. The main resources for the creation of such weapons are spent on the construction of giant uranium mines and enrichment plants. Evidence of the simplicity of the device is the fact that less than a month passed between the production of the plutonium needed for the first bomb and the first Soviet nuclear explosion.
Let us briefly recall the operating principle of such a bomb, known from school physics courses. It is based on the property of uranium and some transuranium elements, for example, plutonium, to release more than one neutron during decay. These elements can decay either spontaneously or under the influence of other neutrons.
The released neutron can leave the radioactive material, or it can collide with another atom, causing another fission reaction. When a certain concentration of a substance (critical mass) is exceeded, the number of newborn neutrons, causing further fission of the atomic nucleus, begins to exceed the number of decaying nuclei. The number of decaying atoms begins to grow like an avalanche, giving birth to new neutrons, that is, a chain reaction occurs. For uranium-235, the critical mass is about 50 kg, for plutonium-239 - 5.6 kg. That is, a ball of plutonium weighing slightly less than 5.6 kg is just a warm piece of metal, and a mass of slightly more lasts only a few nanoseconds.
The actual operation of the bomb is simple: we take two hemispheres of uranium or plutonium, each slightly less than the critical mass, place them at a distance of 45 cm, cover them with explosives and detonate. The uranium or plutonium is sintered into a piece of supercritical mass, and a nuclear reaction begins. All. There is another way to start a nuclear reaction - to compress a piece of plutonium with a powerful explosion: the distance between the atoms will decrease, and the reaction will begin at a lower critical mass. All modern atomic detonators operate on this principle.
The problems with the atomic bomb begin from the moment we want to increase the power of the explosion. Simply increasing the fissile material is not enough - as soon as its mass reaches a critical mass, it detonates. Various ingenious schemes were invented, for example, to make a bomb not from two parts, but from many, which made the bomb begin to resemble a gutted orange, and then assemble it into one piece with one explosion, but still, with a power of over 100 kilotons, the problems became insurmountable.
H-bomb
But fuel for thermonuclear fusion does not have a critical mass. Here the Sun, filled with thermonuclear fuel, hangs overhead, a thermonuclear reaction has been going on inside it for billions of years, and nothing explodes. In addition, during the synthesis reaction of, for example, deuterium and tritium (heavy and superheavy isotope of hydrogen), energy is released 4.2 times more than during the combustion of the same mass of uranium-235.
Making the atomic bomb was an experimental rather than a theoretical process. The creation of a hydrogen bomb required the emergence of completely new physical disciplines: the physics of high-temperature plasma and ultra-high pressures. Before starting to construct a bomb, it was necessary to thoroughly understand the nature of the phenomena that occur only in the core of stars. No experiments could help here - the researchers’ tools were only theoretical physics and higher mathematics. It is no coincidence that a gigantic role in the development of thermonuclear weapons belongs to mathematicians: Ulam, Tikhonov, Samarsky, etc.
Classic super
By the end of 1945, Edward Teller proposed the first hydrogen bomb design, called the "classic super". To create the monstrous pressure and temperature necessary to start the fusion reaction, it was supposed to use a conventional atomic bomb. The “classic super” itself was a long cylinder filled with deuterium. An intermediate “ignition” chamber with a deuterium-tritium mixture was also provided - the synthesis reaction of deuterium and tritium begins at a lower pressure. By analogy with a fire, deuterium was supposed to play the role of firewood, a mixture of deuterium and tritium - a glass of gasoline, and an atomic bomb - a match. This scheme was called a “pipe” - a kind of cigar with an atomic lighter at one end. Soviet physicists began to develop the hydrogen bomb using the same scheme.
However, mathematician Stanislav Ulam, using an ordinary slide rule, proved to Teller that the occurrence of a fusion reaction of pure deuterium in a “super” is hardly possible, and the mixture would require such an amount of tritium that to produce it it would be necessary to practically freeze the production of weapons-grade plutonium in the United States.
Puff with sugar
In mid-1946, Teller proposed another hydrogen bomb design - the “alarm clock”. It consisted of alternating spherical layers of uranium, deuterium and tritium. During the nuclear explosion of the central charge of plutonium, the necessary pressure and temperature were created for the start of a thermonuclear reaction in other layers of the bomb. However, the “alarm clock” required a high-power atomic initiator, and the United States (as well as the USSR) had problems producing weapons-grade uranium and plutonium.
In the fall of 1948, Andrei Sakharov came to a similar scheme. In the Soviet Union, the design was called “sloyka”. For the USSR, which did not have time to produce weapons-grade uranium-235 and plutonium-239 in sufficient quantities, Sakharov’s puff paste was a panacea. And that's why.
In a conventional atomic bomb, natural uranium-238 is not only useless (the neutron energy during decay is not enough to initiate fission), but also harmful because it eagerly absorbs secondary neutrons, slowing down the chain reaction. Therefore, 90% of weapons-grade uranium consists of the isotope uranium-235. However, neutrons resulting from thermonuclear fusion are 10 times more energetic than fission neutrons, and natural uranium-238 irradiated with such neutrons begins to fission excellently. The new bomb made it possible to use uranium-238, which had previously been considered a waste product, as an explosive.
The highlight of Sakharov’s “puff pastry” was also the use of a white light crystalline substance, lithium deuteride 6LiD, instead of acutely deficient tritium.
As mentioned above, a mixture of deuterium and tritium ignites much more easily than pure deuterium. However, this is where the advantages of tritium end, and only disadvantages remain: in its normal state, tritium is a gas, which causes difficulties with storage; tritium is radioactive and decays into stable helium-3, which actively consumes much-needed fast neutrons, limiting the bomb's shelf life to a few months.
Non-radioactive lithium deutride, when irradiated with slow fission neutrons - the consequences of an atomic fuse explosion - turns into tritium. Thus, the radiation from the primary atomic explosion instantly produces a sufficient amount of tritium for a further thermonuclear reaction, and deuterium is initially present in lithium deutride.
It was just such a bomb, RDS-6s, that was successfully tested on August 12, 1953 at the tower of the Semipalatinsk test site. The power of the explosion was 400 kilotons, and there is still debate over whether it was a real thermonuclear explosion or a super-powerful atomic one. After all, the thermonuclear fusion reaction in Sakharov’s puff paste accounted for no more than 20% of the total charge power. The main contribution to the explosion was made by the decay reaction of uranium-238 irradiated with fast neutrons, thanks to which the RDS-6s ushered in the era of the so-called “dirty” bombs.
The fact is that the main radioactive contamination comes from decay products (in particular, strontium-90 and cesium-137). Essentially, Sakharov’s “puff pastry” was a giant atomic bomb, only slightly enhanced by a thermonuclear reaction. It is no coincidence that just one “puff pastry” explosion produced 82% of strontium-90 and 75% of cesium-137, which entered the atmosphere over the entire history of the Semipalatinsk test site.
American bombs
However, it was the Americans who were the first to detonate the hydrogen bomb. On November 1, 1952, the Mike thermonuclear device, with a yield of 10 megatons, was successfully tested at Elugelab Atoll in the Pacific Ocean. It would be hard to call a 74-ton American device a bomb. “Mike” was a bulky device the size of a two-story house, filled with liquid deuterium at a temperature close to absolute zero (Sakharov’s “puff pastry” was a completely transportable product). However, the highlight of “Mike” was not its size, but the ingenious principle of compressing thermonuclear explosives.
Let us recall that the main idea of a hydrogen bomb is to create conditions for fusion (ultra-high pressure and temperature) through a nuclear explosion. In the “puff” scheme, the nuclear charge is located in the center, and therefore it does not so much compress the deuterium as scatter it outwards - increasing the amount of thermonuclear explosive does not lead to an increase in power - it simply does not have time to detonate. This is precisely what limits the maximum power of this scheme - the most powerful “puff” in the world, the Orange Herald, blown up by the British on May 31, 1957, yielded only 720 kilotons.
It would be ideal if we could make the atomic fuse explode inside, compressing the thermonuclear explosive. But how to do that? Edward Teller put forward a brilliant idea: to compress thermonuclear fuel not with mechanical energy and neutron flux, but with the radiation of the primary atomic fuse.
In Teller's new design, the initiating atomic unit was separated from the thermonuclear unit. When the atomic charge was triggered, X-ray radiation preceded the shock wave and spread along the walls of the cylindrical body, evaporating and turning the polyethylene inner lining of the bomb body into plasma. The plasma, in turn, re-emited softer X-rays, which were absorbed by the outer layers of the inner cylinder of uranium-238 - the “pusher”. The layers began to evaporate explosively (this phenomenon is called ablation). Hot uranium plasma can be compared to the jets of a super-powerful rocket engine, the thrust of which is directed into the cylinder with deuterium. The uranium cylinder collapsed, the pressure and temperature of the deuterium reached a critical level. The same pressure compressed the central plutonium tube to a critical mass, and it detonated. The explosion of the plutonium fuse pressed on the deuterium from the inside, further compressing and heating the thermonuclear explosive, which detonated. An intense stream of neutrons splits the uranium-238 nuclei in the “pusher”, causing a secondary decay reaction. All this managed to happen before the moment when the blast wave from the primary nuclear explosion reached the thermonuclear unit. The calculation of all these events, occurring in billionths of a second, required the brainpower of the strongest mathematicians on the planet. The creators of “Mike” experienced not horror from the 10-megaton explosion, but indescribable delight - they managed not only to understand the processes that in the real world occur only in the cores of stars, but also to experimentally test their theories by setting up their own small star on Earth.
Bravo
Having surpassed the Russians in the beauty of the design, the Americans were unable to make their device compact: they used liquid supercooled deuterium instead of Sakharov’s powdered lithium deuteride. In Los Alamos they reacted to Sakharov’s “puff pastry” with a bit of envy: “instead of a huge cow with a bucket of raw milk, the Russians use a bag of powdered milk.” However, both sides failed to hide secrets from each other. On March 1, 1954, near the Bikini Atoll, the Americans tested a 15-megaton bomb “Bravo” using lithium deuteride, and on November 22, 1955, the first Soviet two-stage thermonuclear bomb RDS-37 with a power of 1.7 megatons exploded over the Semipalatinsk test site, demolishing almost half of the test site. Since then, the design of the thermonuclear bomb has undergone minor changes (for example, a uranium shield appeared between the initiating bomb and the main charge) and has become canonical. And there are no more large-scale mysteries of nature left in the world that could be solved with such a spectacular experiment. Perhaps the birth of a supernova.
How Soviet physicists made the hydrogen bomb, what pros and cons this terrible weapon carried, read in the “History of Science” section.
After World War II, it was still impossible to talk about the actual onset of peace - two major world powers entered an arms race. One of the facets of this conflict was the confrontation between the USSR and the USA in the creation of nuclear weapons. In 1945, the United States, the first to enter the race behind the scenes, dropped nuclear bombs on the notorious cities of Hiroshima and Nagasaki. The Soviet Union also carried out work on creating nuclear weapons, and in 1949 they tested the first atomic bomb, the working substance of which was plutonium. Even during its development, Soviet intelligence found out that the United States had switched to developing a more powerful bomb. This prompted the USSR to start producing thermonuclear weapons.
The intelligence officers were unable to find out what results the Americans achieved, and the attempts of Soviet nuclear scientists were not successful. Therefore, it was decided to create a bomb, the explosion of which would occur due to the synthesis of light nuclei, and not the fission of heavy ones, as in an atomic bomb. In the spring of 1950, work began on creating a bomb, which later received the name RDS-6s. Among its developers was the future Nobel Peace Prize laureate Andrei Sakharov, who proposed the idea of designing a charge back in 1948, but later opposed nuclear tests.
Andrey Sakharov
Vladimir Fedorenko/Wikimedia Commons
Sakharov proposed covering a plutonium core with several layers of light and heavy elements, namely uranium and deuterium, an isotope of hydrogen. Subsequently, however, it was proposed to replace deuterium with lithium deuteride - this significantly simplified the design of the charge and its operation. An additional advantage was that lithium, after bombardment with neutrons, produces another isotope of hydrogen - tritium. When tritium reacts with deuterium, it releases much more energy. In addition, lithium also slows down neutrons better. This structure of the bomb gave it the nickname “Sloika”.
A certain challenge was that the thickness of each layer and the final number of layers were also very important for a successful test. According to calculations, from 15% to 20% of the energy released during the explosion came from thermonuclear reactions, and another 75-80% from the fission of uranium-235, uranium-238 and plutonium-239 nuclei. It was also assumed that the charge power would be from 200 to 400 kilotons; the practical result was at the upper limit of the forecasts.
On Day X, August 12, 1953, the first Soviet hydrogen bomb was tested in action. The Semipalatinsk test site where the explosion occurred was located in the East Kazakhstan region. The test of the RDS-6s was preceded by an attempt in 1949 (at that time a ground explosion of a bomb with a yield of 22.4 kilotons was carried out at the test site). Despite the isolated location of the test site, the population of the region experienced first-hand the beauty of nuclear testing. People who lived relatively close to the test site for decades, until the closure of the test site in 1991, were exposed to radiation, and areas many kilometers from the test site were contaminated with nuclear decay products.
The first Soviet hydrogen bomb RDS-6s
Wikimedia Commons
A week before the RDS-6s test, according to eyewitnesses, the military gave money and food to the families living near the test site, but there was no evacuation or information about the upcoming events. The radioactive soil was removed from the test site itself, and nearby structures and observation posts were restored. It was decided to detonate the hydrogen bomb on the surface of the earth, despite the fact that the configuration made it possible to drop it from an airplane.
Previous tests of atomic charges were strikingly different from what nuclear scientists recorded after the Sakharov puff test. The energy output of the bomb, which critics call not a thermonuclear bomb but a thermonuclear-enhanced atomic bomb, was 20 times greater than that of previous charges. This was noticeable to the naked eye in sunglasses: only dust remained from the surviving and restored buildings after the hydrogen bomb test.