The history of human development has always been accompanied by wars as a way to resolve conflicts through violence. Civilization has suffered more than fifteen thousand small and large armed conflicts, the loss of human lives is estimated in the millions. In the nineties of the last century alone, more than a hundred military clashes occurred, involving ninety countries of the world.
At the same time, scientific discoveries and technological progress have made it possible to create weapons of destruction of ever greater power and sophistication of use. In the twentieth century Nuclear weapons became the peak of mass destructive impact and a political instrument.
Atomic bomb device
Modern nuclear bombs as means of destroying the enemy are created on the basis of advanced technical solutions, the essence of which is not widely publicized. But the main elements inherent in this type of weapon can be examined using the example of the design of a nuclear bomb codenamed “Fat Man,” dropped in 1945 on one of the cities of Japan.
The power of the explosion was 22.0 kt in TNT equivalent.
It had the following design features:
- the length of the product was 3250.0 mm, with a diameter of the volumetric part - 1520.0 mm. Total weight more than 4.5 tons;
- the body is elliptical in shape. To avoid premature destruction due to anti-aircraft ammunition and other unwanted impacts, 9.5 mm armored steel was used for its manufacture;
- the body is divided into four internal parts: the nose, two halves of the ellipsoid (the main one is a compartment for the nuclear filling), and the tail.
- the bow compartment is equipped with batteries;
- the main compartment, like the nasal one, is vacuumized to prevent the entry of harmful environments, moisture, and to create comfortable conditions for the bearded man to work;
- the ellipsoid housed a plutonium core surrounded by a uranium tamper (shell). It played the role of an inertial limiter for the course of the nuclear reaction, ensuring maximum activity of weapons-grade plutonium by reflecting neutrons to the side of the active zone of the charge.
A primary source of neutrons, called an initiator or “hedgehog,” was placed inside the nucleus. Represented by beryllium spherical in diameter 20.0 mm with polonium-based outer coating - 210.
It should be noted that the expert community has determined that this design of nuclear weapons is ineffective and unreliable in use. Neutron initiation of the uncontrolled type was not used further .
Operating principle
The process of fission of the nuclei of uranium 235 (233) and plutonium 239 (this is what a nuclear bomb is made of) with a huge release of energy while limiting the volume is called a nuclear explosion. The atomic structure of radioactive metals has an unstable form - they are constantly divided into other elements.
The process is accompanied by the detachment of neurons, some of which fall on neighboring atoms and initiate a further reaction, accompanied by the release of energy.
The principle is as follows: shortening the decay time leads to greater intensity of the process, and the concentration of neurons on bombarding the nuclei leads to a chain reaction. When two elements are combined to a critical mass, a supercritical mass is created, leading to an explosion.
In everyday conditions, it is impossible to provoke an active reaction - high speeds of approach of the elements are needed - at least 2.5 km/s. Achieving this speed in a bomb is possible by using combining types of explosives (fast and slow), balancing the density of the supercritical mass producing an atomic explosion.
Nuclear explosions are attributed to the results of human activity on the planet or its orbit. Natural processes of this kind are possible only on some stars in outer space.
Atomic bombs are rightfully considered the most powerful and destructive weapons of mass destruction. Tactical use solves the problem of destroying strategic, military targets on the ground, as well as deep-based ones, defeating a significant accumulation of enemy equipment and manpower.
It can be applied globally only with the goal of complete destruction of the population and infrastructure in large areas.
To achieve certain goals and perform tactical and strategic tasks, explosions of atomic weapons can be carried out by:
- at critical and low altitudes (above and below 30.0 km);
- in direct contact with the earth's crust (water);
- underground (or underwater explosion).
A nuclear explosion is characterized by the instantaneous release of enormous energy.
Leading to damage to objects and people as follows:
- Shock wave. When an explosion occurs above or on the earth's crust (water) it is called an air wave; underground (water) it is called a seismic explosion wave. An air wave is formed after critical compression of air masses and propagates in a circle until attenuation at a speed exceeding sound. Leads to both direct damage to manpower and indirect damage (interaction with fragments of destroyed objects). The action of excess pressure makes the equipment non-functional by moving and hitting the ground;
- Light radiation. The source is the light part formed by the evaporation of the product with air masses; for ground use, it is soil vapor. The effect occurs in the ultraviolet and infrared spectrum. Its absorption by objects and people provokes charring, melting and burning. The degree of damage depends on the distance of the epicenter;
- Penetrating radiation- these are neutrons and gamma rays moving from the place of rupture. Exposure to biological tissue leads to ionization of cell molecules, leading to radiation sickness in the body. Damage to property is associated with fission reactions of molecules in the damaging elements of ammunition.
- Radioactive contamination. During a ground explosion, soil vapors, dust, and other things rise. A cloud appears, moving in the direction of the movement of air masses. Sources of damage are represented by fission products of the active part of a nuclear weapon, isotopes, and undestroyed parts of the charge. When a radioactive cloud moves, continuous radiation contamination of the area occurs;
- Electromagnetic pulse. The explosion is accompanied by the appearance of electromagnetic fields (from 1.0 to 1000 m) in the form of a pulse. They lead to failure of electrical devices, controls and communications.
The combination of factors of a nuclear explosion causes varying levels of damage to enemy personnel, equipment and infrastructure, and the fatality of the consequences is associated only with the distance from its epicenter.
History of the creation of nuclear weapons
The creation of weapons using nuclear reactions was accompanied by a number of scientific discoveries, theoretical and practical research, including:
- 1905— the theory of relativity was created, which states that a small amount of matter corresponds to a significant release of energy according to the formula E = mc2, where “c” represents the speed of light (author A. Einstein);
- 1938— German scientists conducted an experiment on dividing an atom into parts by attacking uranium with neutrons, which ended successfully (O. Hann and F. Strassmann), and a physicist from Great Britain explained the fact of the release of energy (R. Frisch);
- 1939- scientists from France that when carrying out a chain of reactions of uranium molecules, energy will be released that can produce an explosion of enormous force (Joliot-Curie).
The latter became the starting point for the invention of atomic weapons. Parallel development was carried out by Germany, Great Britain, the USA, and Japan. The main problem was the extraction of uranium in the required volumes for conducting experiments in this area.
The problem was solved faster in the USA by purchasing raw materials from Belgium in 1940.
As part of the project, called Manhattan, from 1939 to 1945, a uranium purification plant was built, a center for the study of nuclear processes was created, and the best specialists - physicists from all over Western Europe - were recruited to work there.
Great Britain, which carried out its own developments, was forced, after the German bombing, to voluntarily transfer the developments on its project to the US military.
It is believed that the Americans were the first to invent the atomic bomb. Tests of the first nuclear charge were carried out in the state of New Mexico in July 1945. The flash from the explosion darkened the sky and the sandy landscape turned to glass. After a short period of time, nuclear charges called “Baby” and “Fat Man” were created.
Nuclear weapons in the USSR - dates and events
The emergence of the USSR as a nuclear power was preceded by long work by individual scientists and government institutions. Key periods and significant dates of events are presented as follows:
- 1920 considered the beginning of the work of Soviet scientists on atomic fission;
- Since the thirties the direction of nuclear physics becomes a priority;
- October 1940— an initiative group of physicists came up with a proposal to use atomic developments for military purposes;
- Summer 1941 in connection with the war, nuclear energy institutes were transferred to the rear;
- Autumn 1941 year, Soviet intelligence informed the country's leadership about the beginning of nuclear programs in Britain and America;
- September 1942- atomic research began to be carried out in full, work on uranium continued;
- February 1943— a special research laboratory was created under the leadership of I. Kurchatov, and general management was entrusted to V. Molotov;
The project was led by V. Molotov.
- August 1945- in connection with the conduct of nuclear bombing in Japan, the high importance of developments for the USSR, a Special Committee was created under the leadership of L. Beria;
- April 1946- KB-11 was created, which began to develop samples of Soviet nuclear weapons in two versions (using plutonium and uranium);
- Mid 1948— work on uranium was stopped due to low efficiency and high costs;
- August 1949- when the atomic bomb was invented in the USSR, the first Soviet nuclear bomb was tested.
The reduction in product development time was facilitated by the high-quality work of intelligence agencies, who were able to obtain information on American nuclear developments. Among those who first created the atomic bomb in the USSR was a team of scientists led by Academician A. Sakharov. They have developed more promising technical solutions than those used by the Americans.
Atomic bomb "RDS-1" In 2015 - 2017, Russia made a breakthrough in improving nuclear weapons and their delivery systems, thereby declaring a state capable of repelling any aggression.
First atomic bomb tests
After testing an experimental nuclear bomb in New Mexico in the summer of 1945, the Japanese cities of Hiroshima and Nagasaki were bombed on August 6 and 9, respectively.
The development of the atomic bomb was completed this year
In 1949, under conditions of increased secrecy, Soviet designers of KB-11 and scientists completed the development of an atomic bomb called RDS-1 (jet engine “C”). On August 29, the first Soviet nuclear device was tested at the Semipalatinsk test site. The Russian atomic bomb - RDS-1 was a “drop-shaped” product, weighing 4.6 tons, with a volumetric diameter of 1.5 m, and a length of 3.7 meters.
The active part included a plutonium block, which made it possible to achieve an explosion power of 20.0 kilotons, commensurate with TNT. The testing site covered a radius of twenty kilometers. The specifics of the test detonation conditions have not been made public to date.
On September 3 of the same year, American aviation intelligence established the presence in the air masses of Kamchatka of traces of isotopes indicating the testing of a nuclear charge. On the twenty-third, the top US official publicly announced that the USSR had succeeded in testing an atomic bomb.
North Korea threatens the US with testing a super-powerful hydrogen bomb in the Pacific Ocean. Japan, which may suffer as a result of the tests, called North Korea's plans completely unacceptable. Presidents Donald Trump and Kim Jong-un argue in interviews and talk about open military conflict. For those who do not understand nuclear weapons, but want to be in the know, The Futurist has compiled a guide.
How do nuclear weapons work?
Like a regular stick of dynamite, a nuclear bomb uses energy. Only it is released not during a primitive chemical reaction, but in complex nuclear processes. There are two main ways to extract nuclear energy from an atom. IN nuclear fission the nucleus of an atom decays into two smaller fragments with a neutron. Nuclear fusion – the process by which the Sun produces energy – involves the joining of two smaller atoms to form a larger one. In any process, fission or fusion, large amounts of thermal energy and radiation are released. Depending on whether nuclear fission or fusion is used, bombs are divided into nuclear (atomic) And thermonuclear .
Can you tell me more about nuclear fission?
Atomic bomb explosion over Hiroshima (1945)
As you remember, an atom is made up of three types of subatomic particles: protons, neutrons and electrons. The center of the atom, called core , consists of protons and neutrons. Protons are positively charged, electrons are negatively charged, and neutrons have no charge at all. The proton-electron ratio is always one to one, so the atom as a whole has a neutral charge. For example, a carbon atom has six protons and six electrons. Particles are held together by a fundamental force - strong nuclear force .
The properties of an atom can change significantly depending on how many different particles it contains. If you change the number of protons, you will have a different chemical element. If you change the number of neutrons, you get isotope the same element that you have in your hands. For example, carbon has three isotopes: 1) carbon-12 (six protons + six neutrons), which is a stable and common form of the element, 2) carbon-13 (six protons + seven neutrons), which is stable but rare, and 3) carbon -14 (six protons + eight neutrons), which is rare and unstable (or radioactive).
Most atomic nuclei are stable, but some are unstable (radioactive). These nuclei spontaneously emit particles that scientists call radiation. This process is called radioactive decay . There are three types of decay:
Alpha decay : The nucleus emits an alpha particle - two protons and two neutrons bound together. Beta decay : A neutron turns into a proton, electron and antineutrino. The ejected electron is a beta particle. Spontaneous fission: the nucleus disintegrates into several parts and emits neutrons, and also emits a pulse of electromagnetic energy - a gamma ray. It is the latter type of decay that is used in a nuclear bomb. Free neutrons emitted as a result of fission begin chain reaction , which releases a colossal amount of energy.
What are nuclear bombs made of?
They can be made from uranium-235 and plutonium-239. Uranium occurs in nature as a mixture of three isotopes: 238 U (99.2745% of natural uranium), 235 U (0.72%) and 234 U (0.0055%). The most common 238 U does not support a chain reaction: only 235 U is capable of this. To achieve maximum explosion power, it is necessary that the content of 235 U in the “filling” of the bomb is at least 80%. Therefore, uranium is produced artificially enrich . To do this, the mixture of uranium isotopes is divided into two parts so that one of them contains more than 235 U.
Typically, isotope separation leaves behind a lot of depleted uranium that is unable to undergo a chain reaction—but there is a way to make it do so. The fact is that plutonium-239 does not occur in nature. But it can be obtained by bombarding 238 U with neutrons.
How is their power measured?
The power of a nuclear and thermonuclear charge is measured in TNT equivalent - the amount of trinitrotoluene that must be detonated to obtain a similar result. It is measured in kilotons (kt) and megatons (Mt). The yield of ultra-small nuclear weapons is less than 1 kt, while super-powerful bombs yield more than 1 mt.
The power of the Soviet “Tsar Bomb” was, according to various sources, from 57 to 58.6 megatons in TNT equivalent; the power of the thermonuclear bomb, which the DPRK tested in early September, was about 100 kilotons.
Who created nuclear weapons?
American physicist Robert Oppenheimer and General Leslie Groves
In the 1930s, Italian physicist Enrico Fermi demonstrated that elements bombarded by neutrons could be transformed into new elements. The result of this work was the discovery slow neutrons , as well as the discovery of new elements not represented on the periodic table. Soon after Fermi's discovery, German scientists Otto Hahn And Fritz Strassmann bombarded uranium with neutrons, resulting in the formation of a radioactive isotope of barium. They concluded that low-speed neutrons cause the uranium nucleus to break into two smaller pieces.
This work excited the minds of the whole world. At Princeton University Niels Bohr worked with John Wheeler to develop a hypothetical model of the fission process. They suggested that uranium-235 undergoes fission. Around the same time, other scientists discovered that the fission process produced even more neutrons. This prompted Bohr and Wheeler to ask an important question: could the free neutrons created by fission start a chain reaction that would release enormous amounts of energy? If this is so, then it is possible to create weapons of unimaginable power. Their assumptions were confirmed by a French physicist Frederic Joliot-Curie . His conclusion became the impetus for developments in the creation of nuclear weapons.
Physicists from Germany, England, the USA, and Japan worked on the creation of atomic weapons. Before the start of World War II Albert Einstein wrote to the US President Franklin Roosevelt that Nazi Germany plans to purify uranium-235 and create an atomic bomb. It now turns out that Germany was far from carrying out a chain reaction: they were working on a “dirty”, highly radioactive bomb. Be that as it may, the US government threw all its efforts into creating an atomic bomb as soon as possible. The Manhattan Project was launched, led by an American physicist Robert Oppenheimer and general Leslie Groves . It was attended by prominent scientists who emigrated from Europe. By the summer of 1945, atomic weapons were created based on two types of fissile material - uranium-235 and plutonium-239. One bomb, the plutonium “Thing,” was detonated during testing, and two more, the uranium “Baby” and the plutonium “Fat Man,” were dropped on the Japanese cities of Hiroshima and Nagasaki.
How does a thermonuclear bomb work and who invented it?
Thermonuclear bomb is based on the reaction nuclear fusion . Unlike nuclear fission, which can occur either spontaneously or forcedly, nuclear fusion is impossible without the supply of external energy. Atomic nuclei are positively charged - so they repel each other. This situation is called the Coulomb barrier. To overcome repulsion, these particles must be accelerated to crazy speeds. This can be done at very high temperatures - on the order of several million Kelvin (hence the name). There are three types of thermonuclear reactions: self-sustaining (take place in the depths of stars), controlled and uncontrolled or explosive - they are used in hydrogen bombs.
The idea of a bomb with thermonuclear fusion initiated by an atomic charge was proposed by Enrico Fermi to his colleague Edward Teller back in 1941, at the very beginning of the Manhattan Project. However, this idea was not in demand at that time. Teller's developments were improved Stanislav Ulam , making the idea of a thermonuclear bomb feasible in practice. In 1952, the first thermonuclear explosive device was tested on Enewetak Atoll during Operation Ivy Mike. However, it was a laboratory sample, unsuitable for combat. A year later, the Soviet Union detonated the world's first thermonuclear bomb, assembled according to the design of physicists Andrey Sakharov And Yulia Kharitona . The device resembled a layer cake, so the formidable weapon was nicknamed “Puff”. In the course of further development, the most powerful bomb on Earth, the “Tsar Bomba” or “Kuzka’s Mother,” was born. In October 1961, it was tested on the Novaya Zemlya archipelago.
What are thermonuclear bombs made of?
If you thought that hydrogen and thermonuclear bombs are different things, you were wrong. These words are synonymous. It is hydrogen (or rather, its isotopes - deuterium and tritium) that is required to carry out a thermonuclear reaction. However, there is a difficulty: in order to detonate a hydrogen bomb, it is first necessary to obtain a high temperature during a conventional nuclear explosion - only then will the atomic nuclei begin to react. Therefore, in the case of a thermonuclear bomb, design plays a big role.
Two schemes are widely known. The first is Sakharov’s “puff pastry”. In the center was a nuclear detonator, which was surrounded by layers of lithium deuteride mixed with tritium, which were interspersed with layers of enriched uranium. This design made it possible to achieve a power within 1 Mt. The second is the American Teller-Ulam scheme, where the nuclear bomb and hydrogen isotopes were located separately. It looked like this: below there was a container with a mixture of liquid deuterium and tritium, in the center of which there was a “spark plug” - a plutonium rod, and on top - a conventional nuclear charge, and all this in a shell of heavy metal (for example, depleted uranium). Fast neutrons produced during the explosion cause atomic fission reactions in the uranium shell and add energy to the total energy of the explosion. Adding additional layers of lithium uranium-238 deuteride makes it possible to create projectiles of unlimited power. In 1953, Soviet physicist Victor Davidenko accidentally repeated the Teller-Ulam idea, and on its basis Sakharov came up with a multi-stage scheme that made it possible to create weapons of unprecedented power. “Kuzka’s Mother” worked exactly according to this scheme.
What other bombs are there?
There are also neutron ones, but this is generally scary. Essentially, a neutron bomb is a low-power thermonuclear bomb, 80% of the explosion energy of which is radiation (neutron radiation). It looks like an ordinary low-power nuclear charge, to which a block with a beryllium isotope, a source of neutrons, has been added. When a nuclear charge explodes, a thermonuclear reaction is triggered. This type of weapon was developed by an American physicist Samuel Cohen . It was believed that neutron weapons destroy all living things, even in shelters, but the range of destruction of such weapons is small, since the atmosphere scatters streams of fast neutrons, and the shock wave is stronger at large distances.
What about the cobalt bomb?
No, son, this is fantastic. Officially, no country has cobalt bombs. Theoretically, this is a thermonuclear bomb with a cobalt shell, which ensures strong radioactive contamination of the area even with a relatively weak nuclear explosion. 510 tons of cobalt can infect the entire surface of the Earth and destroy all life on the planet. Physicist Leo Szilard , who described this hypothetical design in 1950, called it the "Doomsday Machine".
What's cooler: a nuclear bomb or a thermonuclear one?
Full-scale model of "Tsar Bomba"
The hydrogen bomb is much more advanced and technologically advanced than the atomic one. Its explosive power far exceeds that of an atomic one and is limited only by the number of available components. In a thermonuclear reaction, much more energy is released for each nucleon (the so-called constituent nuclei, protons and neutrons) than in a nuclear reaction. For example, the fission of a uranium nucleus produces 0.9 MeV (megaelectronvolt) per nucleon, and the fusion of a helium nucleus from hydrogen nuclei releases an energy of 6 MeV.
Like bombs deliverto the goal?
At first they were dropped from airplanes, but air defense systems were constantly improving, and delivering nuclear weapons in this way turned out to be unwise. With the growth of missile production, all rights to deliver nuclear weapons were transferred to ballistic and cruise missiles of various bases. Therefore, a bomb now means not a bomb, but a warhead.
It is believed that the North Korean hydrogen bomb is too large to be mounted on a rocket - so if the DPRK decides to carry out the threat, it will be carried by ship to the explosion site.
What are the consequences of a nuclear war?
Hiroshima and Nagasaki are only a small part of the possible apocalypse. For example, the “nuclear winter” hypothesis is known, which was put forward by the American astrophysicist Carl Sagan and the Soviet geophysicist Georgy Golitsyn. It is assumed that the explosion of several nuclear warheads (not in the desert or water, but in populated areas) will cause many fires, and a large amount of smoke and soot will spill into the atmosphere, which will lead to global cooling. The hypothesis has been criticized by comparing the effect to volcanic activity, which has little effect on climate. In addition, some scientists note that global warming is more likely to occur than cooling - although both sides hope that we will never know.
Are nuclear weapons allowed?
After the arms race in the 20th century, countries came to their senses and decided to limit the use of nuclear weapons. The UN adopted treaties on the non-proliferation of nuclear weapons and the ban on nuclear tests (the latter was not signed by the young nuclear powers India, Pakistan, and the DPRK). In July 2017, a new treaty on the prohibition of nuclear weapons was adopted.
“Each State Party undertakes never under any circumstances to develop, test, produce, manufacture, otherwise acquire, possess or stockpile nuclear weapons or other nuclear explosive devices,” states the first article of the treaty. .
However, the document will not come into force until 50 states ratify it.
Structurally, the first atomic bomb consisted of the following fundamental components:
- nuclear charge;
- explosive device and automatic charge detonation system with safety systems;
- the ballistic body of the aerial bomb, which housed the nuclear charge and automatic detonation.
The fundamental conditions that determined the design of the RDS-1 bomb were related to:
- with the decision to preserve as much as possible the basic design of the American atomic bomb tested in 1945;
- it is necessary, in the interests of safety, to carry out the final assembly of the charge installed in the ballistic body of the bomb in the conditions of the test site, immediately before detonation;
- with the ability to bomb RDS-1 from a heavy bomber TU-4.
The atomic charge of the RDS-1 bomb was a multilayer structure in which the active substance, plutonium, was transferred to a supercritical state by compressing it through a converging spherical detonation wave in the explosive.
In the center of the nuclear charge was plutonium, structurally consisting of two hemispherical parts. The mass of plutonium was determined in July 1949, upon completion of experiments to measure nuclear constants.
Great successes have been achieved not only by technologists, but also by metallurgists and radiochemists. Thanks to their efforts, already the first plutonium parts contained small amounts of impurities and highly active isotopes. The last point was especially significant, since short-lived isotopes, being the main source of neutrons, could have a negative impact on the likelihood of a premature explosion.
A neutron fuse (NF) was installed in the cavity of the plutonium core in a composite shell of natural uranium. During 1947-1948, about 20 different proposals were considered regarding the principles of operation, design and improvement of the NZ.
One of the most complex components of the first atomic bomb RDS-1 was an explosive charge made from an alloy of TNT and hexogen.
The choice of the outer radius of the explosive was determined, on the one hand, by the need to obtain satisfactory energy release, and, on the other, by the permissible external dimensions of the product and technological production capabilities.
The first atomic bomb was developed in relation to its suspension in the TU-4 aircraft, the bomb bay of which provided the ability to accommodate a product with a diameter of up to 1500 mm. Based on this dimension, the midsection of the ballistic body of the RDS-1 bomb was determined. The explosive charge was structurally a hollow ball and consisted of two layers.
The inner layer was formed from two hemispherical bases made from a domestic alloy of TNT and hexogen.
The outer layer of the RDS-1 explosive charge was assembled from individual elements. This layer, intended to form a spherical converging detonation wave at the base of the explosive and called the focusing system, was one of the main functional units of the charge, which largely determined its tactical and technical performance.
The main purpose of the bomb's automation system was to carry out a nuclear explosion at a given trajectory point. Part of the electrical equipment of the bomb was placed on the carrier aircraft, and its individual elements were placed on the nuclear charge.
To increase the reliability of the product's operation, individual elements of the automatic detonation were made according to a two-channel (duplicate) circuit. In case of failure of the high-altitude fuse systems, a special device (impact sensor) was provided in the bomb design to carry out a nuclear explosion when the bomb hits the ground.
Already at the very initial stage of the development of nuclear weapons, it became obvious that the study of the processes occurring in the charge should follow the computational and experimental path, which made it possible to correct the theoretical analysis based on the results of experiments and experimental data on the gas-dynamic characteristics of nuclear charges.
In general, gas-dynamic testing of a nuclear charge included a number of studies related to setting up experiments and recording fast processes, including the propagation of detonation and shock waves in heterogeneous media.
Studies of the properties of substances at the gas-dynamic stage of the operation of nuclear charges, when the pressure range reaches values of up to hundreds of millions of atmospheres, required the development of fundamentally new research methods, the kinetics of which required high accuracy - up to hundredths of a microsecond. Such requirements led to the development of new methods for recording high-speed processes. It was in the Research Sector KB-11 that the foundations of domestic high-speed photochronography were laid with a scanning speed of up to 10 km/s and a shooting speed of about a million frames per second. The ultra-high-speed recorder developed by A.D. Zakharenkov, G.D. Sokolov and V.K. Bobolev (1948) became the prototype of serial SFR devices developed according to the technical specifications of KB-11 at the Institute of Chemical Physics in 1950.
Note that this photochronograph, driven by an air turbine, already at that time provided an image scanning speed of 7 km/s. The parameters of the serial SFR device (1950), driven by an electric motor, created on its basis are more modest - up to 3.5 km/s.
E.K.Zavoisky |
For the computational and theoretical justification of the performance of the first product, it was fundamentally important to know the parameters of the state of the PV behind the front of the detonation wave, as well as the dynamics of the spherically symmetric compression of the central part of the product. For this purpose, in 1948, E.K. Zavoisky proposed and developed an electromagnetic method for recording the mass velocities of explosion products behind the front of detonation waves, both in a plane and in a spherical explosion.
The distribution of the velocity of the explosion products was carried out in parallel and by the method of pulsed radiography by V.A. Tsukerman and co-workers.
To record fast processes, unique multichannel recorders ETAR-1 and ETAR-2, developed by E.A. Etingof and M.S. Tarasov, with a time resolution close to nanosecond were created. Subsequently, these recorders were replaced by the serially produced OK-4 device developed by A.I. Sokolik (ICP AN).
The use of new methods and new recorders in KB-11 research made it possible, already at the start of work on the creation of atomic weapons, to obtain the necessary data on the dynamic compressibility of structural materials.
Experimental studies of the constants of the working substances included in the physical circuit of the charge created the foundation for the verification of physical concepts of the processes occurring in the charge at the gas-dynamic stage of its operation.
General structure of an atomic bomb
The main elements of nuclear weapons are:
- frame
- automation system
The housing is designed to accommodate a nuclear charge and automation system, and also protects them from mechanical, and in some cases, thermal effects. The automation system ensures the explosion of a nuclear charge at a given point in time and eliminates its accidental or premature activation. It includes:
- safety and cocking system
- emergency detonation system
- charge detonation system
- power supply
- explosion sensor system
The means of delivering nuclear weapons can be ballistic missiles, cruise and anti-aircraft missiles, and aircraft. Nuclear ammunition is used to equip aerial bombs, landmines, torpedoes, and artillery shells (203.2 mm SG and 155 mm SG-USA).
Various systems have been invented to detonate the atomic bomb. The simplest system is an injector-type weapon, in which a projectile made of fissile material crashes into the recipient, forming a supercritical mass. The atomic bomb dropped by the United States on Hiroshima on August 6, 1945, had an injection-type detonator. And it had an energy equivalent of approximately 20 kilotons of TNT.
Nuclear Weapons Museum
The Historical and Memorial Museum of Nuclear Weapons RFNC-VNIIEF (Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics) was opened in the city of Sarov on November 13, 1992. This is the first museum in the country that tells about the main stages of creating the domestic nuclear shield. The first exhibits of the museum appeared before its visitors on this day in the building of the former technical school, where the museum is still located.
Its exhibits are samples of products that have become legends in the history of the country's nuclear industry. What the greatest specialists were working on was, until recently, a huge state secret not only for mere mortals, but also for the developers of nuclear weapons themselves.
The museum's exposition contains exhibits from the very first test model in 1949 to the present day.
Exploded near Nagasaki. The death and destruction that accompanied these explosions was unprecedented. Fear and horror gripped the entire Japanese population, forcing them to surrender in less than a month.
However, after the end of the Second World War, atomic weapons did not fade into the background. The outbreak of the Cold War became a huge psychological pressure factor between the USSR and the USA. Both sides invested huge amounts of money in the development and creation of new nuclear power plants. Thus, several thousand atomic shells have accumulated on our planet over 50 years. This is quite enough to destroy all life on several times. For this reason, in the late 90s, the first disarmament treaty was signed between the United States and Russia to reduce the risk of a worldwide catastrophe. Despite this, currently 9 countries have nuclear weapons, taking their defense to a different level. In this article we will look at why atomic weapons received their destructive power and how atomic weapons work.
In order to understand the full power of atomic bombs, it is necessary to understand the concept of radioactivity. As you know, the smallest structural unit of matter that makes up the whole world around us is the atom. An atom, in turn, consists of a nucleus and something rotating around it. The nucleus consists of neutrons and protons. Electrons have a negative charge, and protons have a positive charge. Neutrons, as their name suggests, are neutral. Usually the number of neutrons and protons is equal to the number of electrons in one atom. However, under the influence of external forces, the number of particles in the atoms of a substance can change.
We are only interested in the option when the number of neutrons changes, and an isotope of the substance is formed. Some isotopes of a substance are stable and occur naturally, while others are unstable and tend to decay. For example, carbon has 6 neutrons. Also, there is an isotope of carbon with 7 neutrons - a fairly stable element found in nature. An isotope of carbon with 8 neutrons is already an unstable element and tends to decay. This is radioactive decay. In this case, unstable nuclei emit three types of rays:
1. Alpha rays are a fairly harmless stream of alpha particles that can be stopped with a thin sheet of paper and cannot cause harm.
Even if living organisms were able to survive the first two, the wave of radiation causes very transient radiation sickness, killing in a matter of minutes. Such damage is possible within a radius of several hundred meters from the explosion. Up to a few kilometers from the explosion, radiation sickness will kill a person in a few hours or days. Those outside the immediate explosion may also be exposed to radiation by eating foods and by inhaling from the contaminated area. Moreover, radiation does not disappear instantly. It accumulates in the environment and can poison living organisms for many decades after the explosion.
The harm from nuclear weapons is too dangerous to be used under any circumstances. The civilian population inevitably suffers from it and irreparable damage is caused to nature. Therefore, the main use of nuclear bombs in our time is deterrence from attack. Even nuclear weapons testing is currently prohibited in most parts of our planet.
But this is something we often don’t know. And why does a nuclear bomb explode, too...
Let's start from afar. Every atom has a nucleus, and the nucleus consists of protons and neutrons - perhaps everyone knows this. In the same way, everyone saw the periodic table. But why are the chemical elements in it placed this way and not otherwise? Certainly not because Mendeleev wanted it that way. The atomic number of each element in the table indicates how many protons are in the nucleus of that element's atom. In other words, iron is number 26 in the table because there are 26 protons in an iron atom. And if there are not 26 of them, it is no longer iron.
But there can be different numbers of neutrons in the nuclei of the same element, which means that the mass of the nuclei can be different. Atoms of the same element with different masses are called isotopes. Uranium has several such isotopes: the most common in nature is uranium-238 (its nucleus has 92 protons and 146 neutrons, totaling 238). It is radioactive, but you cannot make a nuclear bomb from it. But the isotope uranium-235, a small amount of which is found in uranium ores, is suitable for a nuclear charge.
The reader may have come across the expressions “enriched uranium” and “depleted uranium”. Enriched uranium contains more uranium-235 than natural uranium; in a depleted state, correspondingly, less. Enriched uranium can be used to produce plutonium, another element suitable for a nuclear bomb (it is almost never found in nature). How uranium is enriched and how plutonium is obtained from it is a topic for a separate discussion.
So why does a nuclear bomb explode? The fact is that some heavy nuclei tend to decay if they are hit by a neutron. And you won’t have to wait long for a free neutron – there are a lot of them flying around. So, such a neutron hits the uranium-235 nucleus and thereby breaks it into “fragments”. This releases a few more neutrons. Can you guess what will happen if there are nuclei of the same element around? That's right, a chain reaction will occur. This is how it happens.
In a nuclear reactor, where uranium-235 is “dissolved” in the more stable uranium-238, an explosion does not occur under normal conditions. Most of the neutrons that fly out of decaying nuclei fly away into the milk, without finding the uranium-235 nuclei. In the reactor, the decay of nuclei occurs “sluggishly” (but this is enough for the reactor to provide energy). In a single piece of uranium-235, if it is of sufficient mass, neutrons will be guaranteed to break up the nuclei, the chain reaction will start as an avalanche, and... Stop! After all, if you make a piece of uranium-235 or plutonium with the mass required for an explosion, it will explode immediately. This is not the point.
What if you take two pieces of subcritical mass and push them against each other using a remote-controlled mechanism? For example, place both in a tube and attach a powder charge to one so that at the right moment one piece, like a projectile, is fired at the other. Here is the solution to the problem.
You can do it differently: take a spherical piece of plutonium and attach explosive charges over its entire surface. When these charges detonate on command from the outside, their explosion will compress the plutonium from all sides, compress it to a critical density, and a chain reaction will occur. However, accuracy and reliability are important here: all explosive charges must go off at the same time. If some of them work, and some don’t, or some work late, no nuclear explosion will result: the plutonium will not be compressed to a critical mass, but will dissipate in the air. Instead of a nuclear bomb, you will get a so-called “dirty” one.
This is what an implosion-type nuclear bomb looks like. The charges, which are supposed to create a directed explosion, are made in the form of polyhedra in order to cover the surface of the plutonium sphere as tightly as possible.
The first type of device was called a cannon device, the second type - an implosion device.
The "Little Boy" bomb dropped on Hiroshima had a uranium-235 charge and a cannon-type device. The Fat Man bomb, detonated over Nagasaki, carried a plutonium charge, and the explosive device was implosion. Nowadays, gun-type devices are almost never used; implosion ones are more complicated, but at the same time they allow you to regulate the mass of the nuclear charge and spend it more rationally. And plutonium has replaced uranium-235 as a nuclear explosive.
Quite a few years passed, and physicists offered the military an even more powerful bomb - a thermonuclear bomb, or, as it is also called, a hydrogen bomb. It turns out that hydrogen explodes more powerfully than plutonium?
Hydrogen is indeed explosive, but not that explosive. However, there is no “ordinary” hydrogen in a hydrogen bomb; it uses its isotopes – deuterium and tritium. The nucleus of “ordinary” hydrogen has one neutron, deuterium has two, and tritium has three.
In a nuclear bomb, the nuclei of a heavy element are divided into nuclei of lighter ones. In thermonuclear fusion, the reverse process occurs: light nuclei merge with each other into heavier ones. Deuterium and tritium nuclei, for example, combine to form helium nuclei (otherwise known as alpha particles), and the “extra” neutron is sent into “free flight.” This releases significantly more energy than during the decay of plutonium nuclei. By the way, this is exactly the process that takes place on the Sun.
However, the fusion reaction is possible only at ultra-high temperatures (which is why it is called thermonuclear). How to make deuterium and tritium react? Yes, it’s very simple: you need to use a nuclear bomb as a detonator!
Since deuterium and tritium are themselves stable, their charge in a thermonuclear bomb can be arbitrarily huge. This means that a thermonuclear bomb can be made incomparably more powerful than a “simple” nuclear one. The “Baby” dropped on Hiroshima had a TNT equivalent of within 18 kilotons, and the most powerful hydrogen bomb (the so-called “Tsar Bomba”, also known as “Kuzka’s Mother”) was already 58.6 megatons, more than 3255 times more powerful "Baby"!
The “mushroom” cloud from the Tsar Bomba rose to a height of 67 kilometers, and the blast wave circled the globe three times.
However, such gigantic power is clearly excessive. Having “played enough” with megaton bombs, military engineers and physicists took a different path - the path of miniaturization of nuclear weapons. In their conventional form, nuclear weapons can be dropped from strategic bombers like aerial bombs or launched from ballistic missiles; if you miniaturize them, you get a compact nuclear charge that does not destroy everything for kilometers around, and which can be placed on an artillery shell or an air-to-ground missile. Mobility will increase and the range of tasks to be solved will expand. In addition to strategic nuclear weapons, we will receive tactical ones.
A variety of delivery systems have been developed for tactical nuclear weapons - nuclear cannons, mortars, recoilless rifles (for example, the American Davy Crockett). The USSR even had a nuclear bullet project. True, it had to be abandoned - nuclear bullets were so unreliable, so complicated and expensive to manufacture and store that there was no point in them.
"Davy Crockett." A number of these nuclear weapons were in service with the US Armed Forces, and the West German Minister of Defense unsuccessfully sought to arm the Bundeswehr with them.
Speaking about small nuclear weapons, it is worth mentioning another type of nuclear weapon - the neutron bomb. The plutonium charge in it is small, but this is not necessary. If a thermonuclear bomb follows the path of increasing the force of the explosion, then a neutron bomb relies on another damaging factor - radiation. To enhance radiation, a neutron bomb contains a supply of beryllium isotope, which upon explosion produces a huge number of fast neutrons.
According to its creators, a neutron bomb should kill enemy personnel, but leave equipment intact, which can then be captured during an offensive. In practice, it turned out somewhat differently: irradiated equipment becomes unusable - anyone who dares to pilot it will very soon “earn” radiation sickness. This does not change the fact that a neutron bomb explosion is capable of hitting an enemy through tank armor; neutron ammunition was developed by the United States specifically as a weapon against Soviet tank formations. However, tank armor was soon developed that provided some kind of protection from the flow of fast neutrons.
Another type of nuclear weapon was invented in 1950, but never (as far as is known) produced. This is the so-called cobalt bomb - a nuclear charge with a cobalt shell. During the explosion, cobalt, irradiated by a stream of neutrons, becomes an extremely radioactive isotope and is scattered throughout the area, contaminating it. Just one such bomb of sufficient power could cover the entire globe with cobalt and destroy all of humanity. Fortunately, this project remained a project.
What can we say in conclusion? A nuclear bomb is a truly terrible weapon, and at the same time it (what a paradox!) helped maintain relative peace between the superpowers. If your enemy has nuclear weapons, you will think ten times before attacking him. No country with a nuclear arsenal has ever been attacked from outside, and there have been no wars between major states in the world since 1945. Let's hope there won't be any.
