Blast wave from a nuclear bomb. Nuclear strike simulator

After the end of World War II, the countries of the anti-Hitler coalition rapidly tried to get ahead of each other in the development of a more powerful nuclear bomb.

The first test, conducted by the Americans on real objects in Japan, heated up the situation between the USSR and the USA to the limit. The powerful explosions that thundered in Japanese cities and practically destroyed all life in them forced Stalin to abandon many claims on the world stage. Most of the Soviet physicists were urgently "thrown" to the development of nuclear weapons.

When and how did nuclear weapons appear

1896 can be considered the year of birth of the atomic bomb. It was then that French chemist A. Becquerel discovered that uranium is radioactive. The chain reaction of uranium forms a powerful energy that serves as the basis for a terrible explosion. It is unlikely that Becquerel imagined that his discovery would lead to the creation of nuclear weapons - the most terrible weapon in the whole world.

The end of the 19th - beginning of the 20th century was a turning point in the history of the invention of nuclear weapons. It was in this time period that scientists from various countries of the world were able to discover the following laws, rays and elements:

• Alpha, gamma and beta rays;
• Many isotopes of chemical elements with radioactive properties have been discovered;
• The law of radioactive decay was discovered, which determines the time and quantitative dependence of the intensity of radioactive decay, depending on the number of radioactive atoms in the test sample;
• Nuclear isometry was born.

In the 1930s, for the first time, they were able to split the atomic nucleus of uranium by absorbing neutrons. At the same time, positrons and neurons were discovered. All this gave a powerful impetus to the development of weapons that used atomic energy. In 1939, the world's first atomic bomb design was patented. This was done by French physicist Frederic Joliot-Curie.

As a result of further research and development in this area, a nuclear bomb was born. The power and range of destruction of modern atomic bombs is so great that a country that has nuclear potential practically does not need a powerful army, since one atomic bomb is capable of destroying an entire state.

How an atomic bomb works

An atomic bomb consists of many elements, the main of which are:

• Atomic Bomb Corps;
• Automation system that controls the explosion process;
• Nuclear charge or warhead.

The automation system is located in the body of an atomic bomb, along with a nuclear charge. The hull design must be sufficiently reliable to protect the warhead from various external factors and influences. For example, various mechanical, thermal or similar influences, which can lead to an unplanned explosion of great power, capable of destroying everything around.

The task of automation includes complete control over the explosion at the right time, so the system consists of the following elements:

• Device responsible for emergency detonation;
• Power supply of the automation system;
• Undermining sensor system;
• cocking device;
• Safety device.

When the first tests were carried out, nuclear bombs were delivered by planes that had time to leave the affected area. Modern atomic bombs are so powerful that they can only be delivered using cruise, ballistic, or even anti-aircraft missiles.

Atomic bombs use a variety of detonation systems. The simplest of them is a conventional device that is triggered when a projectile hits a target.

One of the main characteristics of nuclear bombs and missiles is their division into calibers, which are of three types:

• Small, the power of atomic bombs of this caliber is equivalent to several thousand tons of TNT;
• Medium (explosion power - several tens of thousands of tons of TNT);
• Large, the charge power of which is measured in millions of tons of TNT.

It is interesting that most often the power of all nuclear bombs is measured precisely in TNT equivalent, since there is no scale for measuring the power of an explosion for atomic weapons.

Algorithms for the operation of nuclear bombs

Any atomic bomb operates on the principle of using nuclear energy, which is released during a nuclear reaction. This procedure is based on either the fission of heavy nuclei or the synthesis of lungs. Since this reaction releases a huge amount of energy, and in the shortest possible time, the radius of destruction of a nuclear bomb is very impressive. Because of this feature, nuclear weapons are classified as weapons of mass destruction.

There are two main points in the process that starts with the explosion of an atomic bomb:

• This is the immediate center of the explosion, where the nuclear reaction takes place;
• The epicenter of the explosion, which is located at the site where the bomb exploded.

The nuclear energy released during the explosion of an atomic bomb is so strong that seismic tremors begin on the earth. At the same time, these shocks bring direct destruction only at a distance of several hundred meters (although, given the force of the explosion of the bomb itself, these shocks no longer affect anything).

Damage factors in a nuclear explosion

The explosion of a nuclear bomb brings not only terrible instantaneous destruction. The consequences of this explosion will be felt not only by people who fell into the affected area, but also by their children, who were born after the atomic explosion. Types of destruction by atomic weapons are divided into the following groups:

• Light radiation that occurs directly during the explosion;
• The shock wave propagated by a bomb immediately after the explosion;
• Electromagnetic pulse;
• penetrating radiation;
• A radioactive contamination that can last for decades.

Although at first glance, a flash of light poses the least threat, in fact, it is formed as a result of the release of a huge amount of thermal and light energy. Its power and strength far exceeds the power of the rays of the sun, so the defeat of light and heat can be fatal at a distance of several kilometers.

The radiation that is released during the explosion is also very dangerous. Although it does not last long, it manages to infect everything around, since its penetrating ability is incredibly high.

The shock wave in an atomic explosion acts like the same wave in conventional explosions, only its power and radius of destruction are much larger. In a few seconds, it causes irreparable damage not only to people, but also to equipment, buildings and the surrounding nature.

Penetrating radiation provokes the development of radiation sickness, and an electromagnetic pulse is dangerous only for equipment. The combination of all these factors, plus the power of the explosion, makes the atomic bomb the most dangerous weapon in the world.

The world's first nuclear weapons test

The first country to develop and test nuclear weapons was the United States of America. It was the US government that allocated huge cash subsidies for the development of promising new weapons. By the end of 1941, many prominent scientists in the field of atomic development were invited to the United States, who by 1945 were able to present a prototype atomic bomb suitable for testing.

The world's first test of an atomic bomb equipped with an explosive device was carried out in the desert in the state of New Mexico. A bomb called "Gadget" was detonated on July 16, 1945. The test result was positive, although the military demanded to test a nuclear bomb in real combat conditions.

Seeing that there was only one step left before victory in the Nazi coalition, and there might not be more such an opportunity, the Pentagon decided to launch a nuclear strike on the last ally of Nazi Germany - Japan. In addition, the use of a nuclear bomb was supposed to solve several problems at once:

• To avoid the unnecessary bloodshed that would inevitably occur if US troops set foot on Imperial Japanese territory;
• To bring the uncompromising Japanese to their knees in one blow, forcing them to agree to conditions favorable to the United States;
• Show the USSR (as a possible rival in the future) that the US Army has a unique weapon that can wipe out any city from the face of the earth;
• And, of course, to see in practice what nuclear weapons are capable of in real combat conditions.

On August 6, 1945, the world's first atomic bomb was dropped on the Japanese city of Hiroshima, which was used in military operations. This bomb was called "Baby", as its weight was 4 tons. The bomb drop was carefully planned, and it hit exactly where it was planned. Those houses that were not destroyed by the blast burned down, as the stoves that fell in the houses provoked fires, and the whole city was engulfed in flames.

After a bright flash, a heat wave followed, which burned all life within a radius of 4 kilometers, and the shock wave that followed it destroyed most of the buildings.

Those who were hit by heatstroke within a radius of 800 meters were burned alive. The blast wave tore off the burnt skin of many. A couple of minutes later, a strange black rain fell, which consisted of steam and ash. Those who fell under the black rain, the skin received incurable burns.

Those few who were lucky enough to survive fell ill with radiation sickness, which at that time was not only not studied, but also completely unknown. People began to develop fever, vomiting, nausea and bouts of weakness.

On August 9, 1945, the second American bomb, called "Fat Man", was dropped on the city of Nagasaki. This bomb had about the same power as the first, and the consequences of its explosion were just as devastating, although people died half as much.

Two atomic bombs dropped on Japanese cities turned out to be the first and only case in the world of the use of atomic weapons. More than 300,000 people died in the first days after the bombing. About 150 thousand more died from radiation sickness.

After the nuclear bombing of Japanese cities, Stalin received a real shock. It became clear to him that the issue of developing nuclear weapons in Soviet Russia was a security issue for the entire country. Already on August 20, 1945, a special committee on atomic energy began to work, which was urgently created by I. Stalin.

Although research on nuclear physics was carried out by a group of enthusiasts back in Tsarist Russia, it was not given due attention in Soviet times. In 1938, all research in this area was completely stopped, and many nuclear scientists were repressed as enemies of the people. After the nuclear explosions in Japan, the Soviet government abruptly began to restore the nuclear industry in the country.

There is evidence that the development of nuclear weapons was carried out in Nazi Germany, and it was German scientists who finalized the “raw” American atomic bomb, so the US government removed all nuclear specialists and all documents related to the development of nuclear weapons from Germany.

The Soviet intelligence school, which during the war was able to bypass all foreign intelligence services, back in 1943 transferred secret documents related to the development of nuclear weapons to the USSR. At the same time, Soviet agents were introduced into all major American nuclear research centers.

As a result of all these measures, already in 1946, the terms of reference for the manufacture of two Soviet-made nuclear bombs were ready:

• RDS-1 (with plutonium charge);
• RDS-2 (with two parts of the uranium charge).

The abbreviation "RDS" was deciphered as "Russia does itself", which almost completely corresponded to reality.

The news that the USSR was ready to release its nuclear weapons forced the US government to take drastic measures. In 1949, the Troyan plan was developed, according to which it was planned to drop atomic bombs on 70 largest cities in the USSR. Only the fear of a retaliatory strike prevented this plan from being realized.

This alarming information coming from Soviet intelligence officers forced scientists to work in an emergency mode. Already in August 1949, the first atomic bomb produced in the USSR was tested. When the US found out about these tests, the Trojan plan was postponed indefinitely. The era of confrontation between the two superpowers, known in history as the Cold War, began.

The most powerful nuclear bomb in the world, known as the Tsar Bomby, belongs precisely to the Cold War period. Soviet scientists have created the most powerful bomb in the history of mankind. Its capacity was 60 megatons, although it was planned to create a bomb with a capacity of 100 kilotons. This bomb was tested in October 1961. The diameter of the fireball during the explosion was 10 kilometers, and the blast wave circled the globe three times. It was this test that forced most countries of the world to sign an agreement to end nuclear tests not only in the earth's atmosphere, but even in space.

Although atomic weapons are an excellent means of intimidating aggressive countries, on the other hand, they are capable of extinguishing any military conflicts in the bud, since all parties to the conflict can be destroyed in an atomic explosion.

At the beginning of the 20th century, thanks to the efforts of Albert Einstein, mankind first learned that at the atomic level, from a small amount of matter, under certain conditions, a huge amount of energy can be obtained. In the 1930s, work in this direction was continued by the German nuclear physicist Otto Hahn, the Englishman Robert Frisch, and the Frenchman Joliot-Curie. It was they who managed in practice to track the results of the fission of the nuclei of atoms of radioactive chemical elements. The chain reaction process simulated in laboratories confirmed Einstein's theory about the ability of a substance in small quantities to release a large amount of energy. Under such conditions, the physics of a nuclear explosion was born - a science that cast doubt on the possibility of the further existence of terrestrial civilization.

The birth of nuclear weapons

Back in 1939, the Frenchman Joliot-Curie realized that exposure to uranium nuclei under certain conditions could lead to an explosive reaction of enormous power. As a result of a nuclear chain reaction, spontaneous exponential fission of uranium nuclei begins, and a huge amount of energy is released. In an instant, the radioactive substance exploded, and the resulting explosion had a huge damaging effect. As a result of the experiments, it became clear that uranium (U235) can be turned from a chemical element into a powerful explosive.

For peaceful purposes, during the operation of a nuclear reactor, the process of nuclear fission of radioactive components is calm and controlled. In a nuclear explosion, the main difference is that a huge amount of energy is released instantly and this continues until the supply of radioactive explosives runs out. For the first time, a person learned about the combat capabilities of the new explosive on July 16, 1945. At the time when the final meeting of the Heads of State of the victors of the war with Germany was taking place in Potsdam, the first test of an atomic warhead took place at the test site in Alamogordo, New Mexico. The parameters of the first nuclear explosion were quite modest. The power of the atomic charge in TNT equivalent was equal to the mass of trinitrotoluene in 21 kilotons, but the force of the explosion and its impact on surrounding objects made an indelible impression on everyone who watched the tests.

Explosion of the first atomic bomb

At first, everyone saw a bright luminous dot, which was visible at a distance of 290 km. from the test site. At the same time, the sound from the explosion was heard within a radius of 160 km. At the place where the nuclear explosive device was installed, a huge crater formed. The funnel from a nuclear explosion reached a depth of more than 20 meters, with an outer diameter of 70 m. On the territory of the test site within a radius of 300-400 meters from the epicenter, the earth's surface was a lifeless lunar surface.

It is interesting to cite the recorded impressions of the participants in the first test of the atomic bomb. “The surrounding air became denser, its temperature instantly rose. Literally a minute later, a huge shock wave swept through the area. At the location of the charge, a huge fireball is formed, after which a mushroom-shaped nuclear explosion cloud began to form in its place. A column of smoke and dust, crowned with a massive nuclear mushroom head, rose to a height of 12 km. Everyone present in the shelter was struck by the scale of the explosion. No one could have imagined the power and strength we faced, ”wrote the head of the Manhattan Project, Leslie Groves, later.

No one, before or since, had at his disposal a weapon of such enormous power. This despite the fact that at that time scientists and the military did not yet have an idea about all the damaging factors of the new weapon. Only the visible main damaging factors of a nuclear explosion were taken into account, such as:

• shock wave of a nuclear explosion;
• light and thermal radiation of a nuclear explosion.

The fact that penetrating radiation and subsequent radioactive contamination during a nuclear explosion is fatal for all living things did not yet have a clear idea. It turned out that these two factors after a nuclear explosion will subsequently become the most dangerous for a person. The zone of complete destruction and devastation is quite small in area in comparison with the zone of contamination of the area by the products of radiation decay. An infected area can have an area of ​​hundreds of kilometers. To the exposure received in the first minutes after the explosion, and to the level of radiation subsequently, contamination of vast territories with radioactive fallout is added. The scale of the catastrophe becomes apocalyptic.

Only later, much later, when atomic bombs were used for military purposes, it became clear how powerful the new weapon was and how severe the consequences of the use of a nuclear bomb would be for people.

The mechanism of atomic charge and the principle of operation

If you do not go into detailed descriptions and technology for creating an atomic bomb, you can briefly describe a nuclear charge in just three phrases:

• there is a subcritical mass of radioactive material (uranium U235 or plutonium Pu239);
• creation of certain conditions for the start of a chain reaction of nuclear fission of radioactive elements (detonation);
• creation of a critical mass of fissile material.

The whole mechanism can be depicted in a simple and understandable drawing, where all parts and details are in strong and close interaction with each other. As a result of the detonation of a chemical or electrical detonator, a detonation spherical wave is launched, compressing the fissile material to a critical mass. The nuclear charge is a multilayer structure. Uranium or plutonium is used as the main explosive. A certain amount of TNT or RDX can serve as a detonator. Further, the compression process becomes uncontrollable.

The speed of the ongoing processes is enormous and comparable to the speed of light. The time interval from the start of detonation to the start of an irreversible chain reaction takes no more than 10-8 s. In other words, it takes only 10-7 seconds to power 1 kg of enriched uranium. This value denotes the time of a nuclear explosion. The reaction of thermonuclear fusion, which is the basis of a thermonuclear bomb, proceeds with a similar speed, with the difference that a nuclear charge sets in motion an even more powerful one - a thermonuclear charge. A thermonuclear bomb has a different principle of operation. Here we are dealing with the reaction of the synthesis of light elements into heavier ones, as a result of which, again, a huge amount of energy is released.

In the process of fission of uranium or plutonium nuclei, a huge amount of energy is generated. At the center of a nuclear explosion, the temperature is 107 Kelvin. Under such conditions, a colossal pressure arises - 1000 atm. Atoms of fissile matter turn into plasma, which becomes the main result of the chain reaction. During the accident at the 4th reactor of the Chernobyl nuclear power plant, there was no nuclear explosion, since the fission of radioactive fuel was carried out slowly and was accompanied only by intense heat release.

The high speed of the processes occurring inside the charge leads to a rapid jump in temperature and an increase in pressure. It is these components that form the nature, factors and power of a nuclear explosion.

Types and types of nuclear explosions

The chain reaction that has started can no longer be stopped. In thousandths of a second, a nuclear charge, consisting of radioactive elements, turns into a plasma clot, torn apart by high pressure. A successive chain of a number of other factors begins that have a damaging effect on the environment, infrastructure facilities and living organisms. The only difference in damage is that a small nuclear bomb (10-30 kilotons) causes less destruction and less severe consequences than a large nuclear explosion with a yield of 100 more megatons.

The damaging factors depend not only on the power of the charge. To assess the consequences, the conditions for detonating a nuclear weapon are important, which type of nuclear explosion is observed in this case. Undermining the charge can be carried out on the surface of the earth, underground or under water, according to the conditions of use, we are dealing with the following types:

• air nuclear explosions carried out at certain heights above the earth's surface;
• high-altitude explosions carried out in the planet's atmosphere at altitudes above 10 km;
• land (surface) nuclear explosions carried out directly above the surface of the earth or above the water surface;
• underground or underwater explosions carried out in the surface thickness of the earth's crust or under water, at a certain depth.

In each individual case, certain damaging factors have their own strength, intensity and characteristics of the action, leading to certain results. In one case, a targeted destruction of the target occurs with minimal destruction and radioactive contamination of the territory. In other cases, one has to deal with large-scale devastation of the area and the destruction of objects, instant destruction of all life occurs, and strong radioactive contamination of vast territories is observed.

An air nuclear explosion, for example, differs from a ground-based detonation method in that the fireball does not come into contact with the earth's surface. In such an explosion, dust and other small fragments are combined into a dust column that exists separately from the explosion cloud. Accordingly, the area of ​​damage also depends on the height of the explosion. Such explosions can be high and low.

The first tests of atomic warheads both in the USA and in the USSR were mainly of three types, ground, air and underwater. Only after the Treaty on the Limitation of Nuclear Tests came into force, nuclear explosions in the USSR, in the USA, in France, in China and in Great Britain began to be carried out only underground. This made it possible to minimize environmental pollution with radioactive products, to reduce the area of ​​exclusion zones that arose near military training grounds.

The most powerful nuclear explosion in the history of nuclear testing took place on October 30, 1961 in the Soviet Union. A bomb with a total weight of 26 tons and a capacity of 53 megatons was dropped in the area of ​​the Novaya Zemlya archipelago from a Tu-95 strategic bomber. This is an example of a typical high air burst, as the explosion occurred at an altitude of 4 km.

It should be noted that the detonation of a nuclear warhead in the air is characterized by a strong effect of light radiation and penetrating radiation. The flash of a nuclear explosion is clearly visible tens and hundreds of kilometers from the epicenter. In addition to powerful light radiation and a strong shock wave diverging around 3600, an air explosion becomes a source of strong electromagnetic disturbance. An electromagnetic pulse generated during an air nuclear explosion within a radius of 100-500 km. able to disable the entire ground electrical infrastructure and electronics.

A striking example of a low air burst was the August 1945 atomic bombing of the Japanese cities of Hiroshima and Nagasaki. Bombs "Fat Man" and "Baby" worked at an altitude of half a kilometer, thereby covering almost the entire territory of these cities with a nuclear explosion. Most of the inhabitants of Hiroshima died in the first seconds after the explosion, as a result of exposure to intense light, heat and gamma radiation. The shock wave completely destroyed the city buildings. In the case of the bombing of the city of Nagasaki, the effect of the explosion was weakened by the features of the relief. The hilly terrain allowed some areas of the city to avoid the direct action of light rays, and reduced the impact force of the blast wave. But during such an explosion, extensive radioactive contamination of the area was observed, which subsequently led to serious consequences for the population of the destroyed city.

Low and high air bursts are the most common modern means of weapons of mass destruction. Such charges are used to destroy the accumulation of troops and equipment, cities and ground infrastructure.

A high-altitude nuclear explosion differs in the method of application and the nature of the action. The detonation of a nuclear weapon is carried out at an altitude of more than 10 km, in the stratosphere. With such an explosion, a bright sun-like flash of large diameter is observed high in the sky. Instead of clouds of dust and smoke, a cloud soon forms at the site of the explosion, consisting of molecules of hydrogen, carbon dioxide and nitrogen evaporated under the influence of high temperatures.

In this case, the main damaging factors are the shock wave, light radiation, penetrating radiation and EMP of a nuclear explosion. The higher the charge detonation height, the lower the shock wave strength. Radiation and light emission, on the contrary, only increase with increasing altitude. Due to the absence of significant movement of air masses at high altitudes, radioactive contamination of territories in this case is practically reduced to zero. Explosions at high altitudes, made within the ionosphere, disrupt the propagation of radio waves in the ultrasonic range.

Such explosions are mainly aimed at destroying high-flying targets. These can be reconnaissance aircraft, cruise missiles, strategic missile warheads, artificial satellites and other space attack weapons.

A ground-based nuclear explosion is a completely different phenomenon in military tactics and strategy. Here, a certain area of ​​the earth's surface is directly affected. A warhead can be detonated over an object or over water. The first tests of atomic weapons in the United States and in the USSR took place in this form.

A distinctive feature of this type of nuclear explosion is the presence of a pronounced mushroom cloud, which is formed due to the huge volumes of soil and rock particles raised by the explosion. At the very first moment, a luminous hemisphere is formed at the site of the explosion, with its lower edge touching the surface of the earth. During a contact detonation, a funnel is formed at the epicenter of the explosion, where the nuclear charge exploded. The depth and diameter of the funnel depends on the power of the explosion itself. When using small tactical ammunition, the diameter of the funnel can reach two or three tens of meters. When a nuclear bomb is detonated with high power, the dimensions of the crater often reach hundreds of meters.

The presence of a powerful mud and dust cloud contributes to the fact that the bulk of the radioactive products of the explosion falls back to the surface, making it completely contaminated. Smaller dust particles enter the surface layer of the atmosphere and, together with the air masses, scatter over vast distances. If an atomic charge is blown up on the surface of the earth, the radioactive trace from the produced ground explosion can stretch for hundreds and thousands of kilometers. During the accident at the Chernobyl nuclear power plant, radioactive particles that entered the atmosphere fell out along with precipitation on the territory of the Scandinavian countries, which are located 1000 km from the disaster site.

Ground explosions can be carried out to destroy and destroy objects of great strength. Such explosions can also be used if the goal is to create a vast zone of radioactive contamination of the area. In this case, all five damaging factors of a nuclear explosion are in effect. Following the thermodynamic shock and light radiation, an electromagnetic impulse comes into play. The shock wave and penetrating radiation complete the destruction of the object and manpower within the radius of action. Finally, there is radioactive contamination. Unlike the ground-based method of detonation, a surface nuclear explosion lifts huge masses of water into the air, both in liquid form and in a vapor state. The destructive effect is achieved due to the impact of the air shock wave and the large excitement resulting from the explosion. The water raised into the air prevents the spread of light radiation and penetrating radiation. Due to the fact that water particles are much heavier and are a natural neutralizer of the activity of elements, the intensity of the spread of radioactive particles in the air space is negligible.

An underground explosion of a nuclear weapon is carried out at a certain depth. Unlike ground explosions, there is no glowing area here. All the huge impact force is taken by the earth rock. The shock wave diverges in the thickness of the earth, causing a local earthquake. The huge pressure created during the explosion forms a column of soil collapse, going to great depths. As a result of rock subsidence, a funnel is formed at the site of the explosion, the dimensions of which depend on the power of the charge and the depth of the explosion.

Such an explosion is not accompanied by a mushroom cloud. The column of dust that rose at the site of the detonation of the charge has a height of only a few tens of meters. The shock wave converted into seismic waves and local surface radioactive contamination are the main damaging factors in such explosions. As a rule, this type of detonation of a nuclear charge is of economic and applied importance. To date, most nuclear tests are carried out underground. In the 1970s and 1980s, national economic problems were solved in a similar way, using the colossal energy of a nuclear explosion to destroy mountain ranges and form artificial reservoirs.

On the map of nuclear test sites in Semipalatinsk (now the Republic of Kazakhstan) and in the state of Nevada (USA) there are a huge number of craters, traces of underground nuclear tests.

Underwater detonation of a nuclear charge is carried out at a given depth. In this case, there is no light flash during the explosion. A water column 200-500 meters high appears on the surface of the water at the place of explosion, which is crowned with a cloud of spray and steam. The formation of a shock wave occurs immediately after the explosion, causing disturbances in the water column. The main damaging factor of the explosion is the shock wave, which transforms into waves of great height. With the explosion of high-power charges, the height of the waves can reach 100 meters or more. In the future, a strong radioactive contamination is observed at the site of the explosion and in the adjacent territory.

Methods of protection against damaging factors of a nuclear explosion

As a result of the explosive reaction of a nuclear charge, a huge amount of thermal and light energy is generated, which can not only destroy and destroy inanimate objects, but also kill all living things over a large area. In the epicenter of the explosion and in its immediate vicinity, as a result of intense exposure to penetrating radiation, light, thermal radiation and shock waves, all living things die, military equipment is destroyed, buildings and structures are destroyed. With the distance from the epicenter of the explosion and over time, the strength of the damaging factors decreases, giving way to the last destructive factor - radioactive contamination.

It is useless to seek salvation for those who have fallen into the epicenter of a nuclear apocalypse. Neither a strong bomb shelter nor personal protective equipment will save here. Injuries and burns received by a person in such situations are incompatible with life. The destruction of infrastructure facilities is total and cannot be restored. In turn, those who found themselves at a considerable distance from the explosion site can count on salvation using certain skills and special methods of protection.

The main damaging factor in a nuclear explosion is the shock wave. The area of ​​high pressure formed at the epicenter affects the air mass, creating a shock wave that propagates in all directions at supersonic speed.

The propagation speed of the blast wave is as follows:

• on flat terrain, the shock wave overcomes 1000 meters from the epicenter of the explosion in 2 seconds;
• at a distance of 2000 m from the epicenter, the shock wave will overtake you in 5 seconds;
• being at a distance of 3 km from the explosion, the shock wave should be expected in 8 seconds.

After the passage of the blast wave, an area of ​​low pressure arises. In an effort to fill the rarefied space, the air goes in the opposite direction. The created vacuum effect causes another wave of destruction. Seeing a flash, before the arrival of the blast wave, you can try to find shelter, reducing the effects of the impact of the shock wave.

Light and heat radiation at a great distance from the epicenter of the explosion lose their strength, so if a person managed to take cover at the sight of a flash, you can count on salvation. Much more terrible is penetrating radiation, which is a rapid stream of gamma rays and neutrons that propagate at the speed of light from the luminous area of ​​​​the explosion. The most powerful effect of penetrating radiation occurs in the first seconds after the explosion. While in shelter or shelter, there is a high probability of avoiding a direct hit of deadly gamma radiation. Penetrating radiation causes severe damage to living organisms, causing radiation sickness.

If all the above listed damaging factors of a nuclear explosion are of a short-term nature, then radioactive contamination is the most insidious and dangerous factor. Its destructive effect on the human body occurs gradually, over time. The amount of residual radiation and the intensity of radioactive contamination depends on the power of the explosion, terrain conditions and climatic factors. The radioactive products of the explosion, mixed with dust, small fragments and fragments, enter the surface air layer, after which, together with precipitation or independently, they fall to the surface of the earth. The radiation background in the zone of application of nuclear weapons is hundreds of times higher than the natural background radiation, creating a threat to all living things. Being in the territory subjected to a nuclear strike, contact with any objects should be avoided. Personal protective equipment and a dosimeter will reduce the likelihood of radioactive contamination.

The main damaging factors of a nuclear explosion are the shock wave (the formation of which consumes 50% of the energy of the explosion), light radiation (35%), penetrating radiation (5%) and radioactive contamination (10%). An electromagnetic pulse and secondary damaging factors are also distinguished.

shock wave- the main factor of the destructive and damaging effect, is a zone of compressed air, which is formed during the instantaneous expansion of gases in the center of the explosion and spreads at great speed in all directions, causing destruction of buildings, structures and damage to people. The range of the shock wave depends on the power and type of explosion, as well as the nature of the terrain. A shock wave consists of a shock wave front, compression and rarefaction zones.

The strength of the shock wave depends on the excess pressure at its front, which is measured by the number of kilogram-forces falling per square centimeter of the surface (kgf / cm 2), or in pascals (Pa): 1 Pa \u003d 0.00001 kgf / cm 2, 1 kgf / cm 2 \u003d 100 kPa (kilopascal).

During the explosions of 13-kiloton bombs in Hiroshima and Nagasaki, the radius of action was expressed approximately in the following figures: a zone of continuous destruction and destruction within a radius of up to 800 - 900 m (overpressure over 1 kg / cm 2) - the destruction of all buildings and structures and almost 100% loss of life; a zone of severe destruction and severe and medium damage to people within a radius of up to 2-2.5 km (overpressure 0.3-1 kg / cm 2); a zone of weak destruction and weak and accidental injuries of people within a radius of up to 3-4 km (overpressure 0.04-0.2 kg / cm 2).

It is also necessary to take into account the "throwing" effect of the shock wave and the formation of secondary projectiles in the form of flying fragments of buildings (bricks, boards, glass, etc.) that injure people.

Under the action of a shock wave on an openly located personnel at an overpressure of more than 1 kg / cm 2 (100 kPa), extremely severe, fatal injuries occur (bone fractures, hemorrhages, bleeding from the nose, ears, contusions, barotrauma of the lungs, ruptures of hollow organs, wounds secondary projectiles, the syndrome of prolonged crushing under the ruins, etc.), with a pressure at the front of 0.5-0.9 kg / cm 2 - severe injuries; 0.4-0.5 kg / cm 2 - moderate; 0.2-0.3 kg / cm 2 - light lesions. However, even with an excess pressure of 0.2-0.3 kg / cm2, even severe injuries are possible under the action of the velocity pressure and the propelling action of the shock wave, if the person did not have time to take cover and will be thrown a few meters by the wave or will be injured from secondary projectiles.

During ground and especially underground nuclear explosions, strong vibrations (shaking) of the earth are observed, which can be roughly compared with an earthquake with a force of up to 5-7 points.

The means of protection against the shock wave are various kinds of shelters and shelters, as well as terrain folds, since the front of the shock wave after reflection from the ground runs parallel to the surface and the pressure in the recesses is much less.

Trenches, trenches and shelters reduce losses from the shock wave from 3 to 10 times.

The shock wave radius of more powerful nuclear weapons (more than 20,000 tons of TNT) is equal to the cube root of the ratio of TNT, multiplied by the range of a 20-kiloton bomb. For example, with an increase in the power of the explosion by a factor of 1000, the radius of action increases by a factor of 10 (Table 10).

light emission. From a fireball with an extremely high temperature, a powerful stream of light and heat (infrared) rays of high temperature emanates for 10-20 seconds. Near the fireball, everything (even minerals and metals) melts, turns into a gaseous state and rises with a mushroom cloud. The radius of action of light radiation depends on the power and type of explosion (the largest with an air explosion) and the transparency of the atmosphere (rain, fog, snow sharply reduce the effect due to the absorption of light rays).

Table 9

Approximate ranges of shock wave and light radiation (km)

Characteristic	Explosion power
Zone of complete destruction and death of unprotected people (Rf-100 kPa)
Zone of severe damage, severe and moderate injuries (Rf-30-90 kPa)
Zone of medium and weak destruction, medium and mild injuries (Rf-10-30 kPa)
III degree
II degree
I degree

Note. Pf - excess pressure on the front of the shock wave. The numerator gives data for air explosions, the denominator - for ground explosions. 100 kPa \u003d 1 kg / cm 2 (1 atm.).

Light radiation causes ignition of combustible substances and massive fires, and in humans and animals, burns of the body of varying severity. In Hiroshima, about 60,000 buildings burned down and about 82% of the affected people had body burns.

The degree of damaging effect is determined by the light pulse, that is, the amount of energy falling on 1 m 2 of the surface of the illuminated body, and is measured in kilojoules per 1 m 2. A light pulse of 100-200 kJ / m 2 (2-5 cal / cm 2) causes a burn of I degree, 200-400 kJ / m 2 (5-10 cal / cm 2) - II, more than 400 kJ / m 2 ( over 10 cal / cm 2) - III degree (100 kJ / m 2).

The degree of damage to materials by light radiation depends on the degree of their heating, which in turn depends on a number of factors: the magnitude of the light pulse, the properties of the material, the heat absorption coefficient, humidity, combustibility of the material, etc. Dark-colored materials absorb light energy more than light . For example, black cloth absorbs 99% of the incident light energy, khaki material absorbs 60%, white cloth absorbs 25%.

In addition, the light pulse causes blinding people, especially at night, when the pupil is dilated. Blinding is more often temporary due to depletion of visual purple (rhodopsin). But at close range, there may be a retinal burn and a more permanent blindness. Therefore, you can not look at the flash of light, you must immediately close your eyes. Currently, there are protective photochromic glasses that lose their transparency from light radiation and protect the eyes.

penetrating radiation. At the time of the explosion, for about 15-20 seconds, as a result of nuclear and thermonuclear reactions, a very powerful stream of ionizing radiation emanates: gamma rays, neutrons, alpha and beta particles. But only gamma rays and neutron flux are related to penetrating radiation, since alpha and beta particles have a short range in air and do not have penetrating power.

The radius of action of penetrating radiation during air explosions of a 20-kiloton bomb is approximately expressed in the following figures: up to 800 m - 100% mortality (dose up to 10,000 R); 1.2 km - 75% mortality (dose up to 1000 R); 2 km - radiation sickness I-II degree (dose 50-200 R). During explosions of thermonuclear megaton munitions, fatal injuries can be within a radius of up to 3-4 km due to the large size of the fireball at the time of the explosion, while the neutron flux becomes of great importance.

The total doses of gamma and neutron exposure of unprotected people in a nuclear focus can be determined from the graphs (Fig. 43).

Especially strongly penetrating radiation is manifested in the explosions of neutron bombs. In the explosion of a neutron bomb with a capacity of 1 thousand tons of TNT, when the shock wave and light radiation strike within a radius of 130-150 m, the total gamma-neutron radiation is: within a radius of 1 km - up to 30 Gy (3000 rad), 1.2 km -8.5 Gy; 1.6 km - 4 Gy, up to 2 km - 0.75-1 Gy.

Rice. 43. Total dose of penetrating radiation during nuclear explosions.

Various shelters and structures can serve as a means of protection against penetrating radiation. Moreover, gamma rays are more strongly absorbed and retained by heavy materials with a high density, and neutrons are better absorbed by light substances. To calculate the required thickness of protective materials, the concept of a layer of half attenuation is introduced, that is, the thickness of the material, which reduces radiation by a factor of 2 (Table 11).

Table 11

Half attenuation layer (K ​​0.5). cm

To calculate the protective power of shelters, the formula K s \u003d 2 S / K 0.5 is used

where: K z - protection factor of the shelter, S - thickness of the protective layer, K 0.5 - layer of half attenuation. From this formula it follows that 2 layers of half attenuation reduce radiation by 4 times, 3 layers by 8 times, etc.

For example, a 112 cm earth cover reduces gamma exposure by a factor of 256:

K z \u003d 2 112/14 \u003d 2 8 \u003d 256 (times).

In field shelters, it is required that the protection factor for gamma radiation be equal to 250-1000, that is, an earthen floor with a thickness of 112-140 cm is required.

Radioactive contamination of the area. No less dangerous damaging factor of nuclear weapons is radioactive contamination of the area. The peculiarity of this factor lies in the fact that very large territories are exposed to radioactive contamination, and in addition, its effect lasts for a long time (weeks, months and even years).

So, during a test explosion made by the USA on March 1, 1954 in the South Pacific Ocean in the area of ​​\u200b\u200babout. Bikini (10-megaton bomb), radioactive contamination was noted at a distance of up to 600 km. At the same time, residents of the Marshall Islands (267 people), who were at a distance of 200 to 540 km, and 23 Japanese fishermen on a fishing boat, located at a distance of 160 km from the center of the explosion, were hit.

Sources of radioactive contamination are radioactive isotopes (fragments) formed during nuclear fission, induced radioactivity and the remnants of the unreacted part of the nuclear charge.

Radioactive fission isotopes of uranium and plutonium are the main and most dangerous source of contamination. In a chain reaction of fission of uranium or plutonium, their nuclei are divided into two parts with the formation of various radioactive isotopes. These isotopes subsequently undergo an average of three radioactive decays with the emission of beta particles and gamma rays, turning after that into non-radioactive substances (barium and lead). Thus, in a mushroom cloud there are about 200 radioactive isotopes of 35 elements of the middle part of the periodic table - from zinc to gadolinium.

The most common isotopes among fission fragments are the isotopes of yttrium, tellurium, molybdenum, iodine, xenon, barium, lanthanum, strontium, cesium, zirconium, and others. , causing the entire mushroom cloud to become radioactive. Where radioactive dust settles, the terrain and all objects turn out to be contaminated with radioactive substances (contaminated products of a nuclear explosion, PYaV).

Induced radioactivity arises under the action of a neutron flux. Neutrons are able to interact with the nuclei of various elements (air, soil and other objects), as a result of which many elements become radioactive and begin to emit beta particles and gamma rays. For example, when a neutron is captured, sodium becomes a radioactive isotope:

11 23 Na + n 1 → 11 24 Na,

which undergoes beta decay with gamma radiation and has a half-life of 14.9 hours: 11 24 Na - 12 24 Mg + ß - + γ.

Of the radioactive isotopes formed during neutron irradiation of soil, manganese-52, silicon-31, sodium-24, and calcium-45 are of the greatest importance.

However, induced radioactivity plays a relatively small role, since it occupies a small area (depending on the explosion power within a maximum radius of 2-3 km), and isotopes are formed mainly with a short half-life.

But the induced radioactivity of soil elements and in a mushroom cloud is of great importance in thermonuclear explosions and explosions of neutron bombs, since thermonuclear fusion reactions are accompanied by the emission of a large number of fast neutrons.

The unreacted part of the nuclear charge is the undivided uranium or plutonium atoms. The fact is that the efficiency of the nuclear charge is very low (about 10%), the remaining uranium and plutonium atoms do not have time to undergo fission, the unreacted part is sprayed into tiny particles by the force of the explosion and settles in the form of precipitation from the mushroom cloud. However, this unreacted part of the nuclear charge plays an insignificant role. This is due to the fact that uranium and plutonium have very long half-lives, in addition, they emit alpha particles and are dangerous only when ingested. So, the greatest danger is the radioactive fragments of the fission of uranium and plutonium. The total gamma activity of these isotopes is extremely high: 1 minute after the explosion of a 20-kiloton bomb, it is 8.2 10 11 Ci.

During air nuclear explosions, radioactive contamination of the area in the explosion zone is of no practical importance. This is explained by the fact that the luminous zone does not come into contact with the earth, therefore a relatively small, thin mushroom cloud is formed, consisting of very fine radioactive dust, which rises and infects the atmosphere and stratosphere. Subsidence of RS occurs over large areas over several years (mainly strontium and cesium). There is contamination of the area only within a radius of 800-3000 m, mainly due to induced radioactivity, which quickly (after 2-5 hours) practically disappears.

With ground and low air explosions, the radioactive contamination of the area will be the strongest, since the fireball is in contact with the ground. A massive mushroom cloud is formed, containing a large amount of radioactive dust, which is carried by the wind and settles along the path of the cloud, creating a radioactive trace of the cloud in the form of a strip of earth contaminated with radioactive fallout. Some of the largest particles settle around the stem of the mushroom cloud.

During underground nuclear explosions, very intense contamination is observed near the center of the explosion, part of the radioactive dust was also carried by the wind and settles along the path of the cloud, but the area of ​​the contaminated territory is smaller than in a ground explosion of the same power.

During underwater explosions, a very strong radioactive contamination of a reservoir is observed near the explosion. In addition, radioactive rain falls along the path of the cloud at considerable distances. At the same time, a strong induced, radioactivity of sea water containing a lot of sodium is also noted.

The intensity of radioactive contamination of the area is measured by two methods: the level of radiation in roentgens per hour (R / h) and the dose of radiation in grays (rads) for a certain period of time that personnel can receive in the contaminated area.

In the region of the center of a nuclear explosion, the contaminated area has the shape of a circle somewhat elongated in the direction of the wind. The trace of radioactive fallout along the path of the cloud usually has the shape of an ellipse, the axis of which is directed in the direction of the wind. The width of the trace of radioactive fallout is 5-10 times less than the length of the trace (ellipse).

In a ground explosion of a 10-megaton thermonuclear bomb, the contamination zone with a radiation level of 100 R/h has a length of up to 325 km and a width of up to 50 km, and a zone with a radiation level of 0.5 R/h has a length of more than 1000 km. From this it is clear what huge territories can be contaminated with radioactive fallout.

The start of radioactive fallout depends on the wind speed and can be determined by the formula: t 0 = R/v, where t 0 is the start of fallout, R is the distance from the center of the explosion in kilometers, v is the wind speed in kilometers per hour.

The level of radiation in the contaminated area is constantly decreasing due to the conversion of short-lived isotopes into non-radioactive stable substances.

This decrease occurs according to the rule: with a sevenfold increase in the time elapsed since the explosion, the radiation level decreases by a factor of 10. For example: if after 1 hour the radiation level is equal to 1000 R/h, then after 7 hours - 100 R/h, after 49 hours - 10 R/h, after 343 hours (2 weeks) - 1 R/h.

The level of radiation decreases especially quickly in the first hours and days after the explosion, and then substances with a long half-life remain and the decrease in the level of radiation occurs very slowly.

The exposure dose (gamma rays) to unprotected personnel in the contaminated area depends on the level of radiation, the time spent in the contaminated area, and the rate of decline in the level of radiation.

It is possible to calculate the dose of radiation for the period until the complete decay of radioactive substances.

Radioactive fallout infects the area unevenly. The highest levels of radiation are near the center of the explosion and the axis of the ellipse, while away from the center of the explosion and from the axis of the track, the radiation levels will be lower. In accordance with this, the trace of radioactive fallout is usually divided into 4 zones (see p. 251).

The means of protection against radiation sickness in contaminated areas are shelters, shelters, buildings, structures, military equipment, etc., which weaken radiation exposure, and with appropriate sealing (closing doors, windows, etc.), they also prevent the penetration of radioactive dust.

In the absence of shelters, it is necessary to leave the zones of strong and dangerous contamination as soon as possible, that is, to limit the time of exposure of people. The most probable ways of hazardous effects of radioactive substances from a nuclear explosion on people are general external gamma irradiation and contamination of the skin. Internal exposure is not significant in the damaging effect.

Note. It should be added that in Europe there are more than 200 nuclear reactors, the destruction of which can lead to very strong contamination of vast areas of territory with radioactive fallout for a long time. An example of this is the release of radioactive substances from the nuclear reactor accident at Chernobyl.

Nuclear winter. Soviet and American scientists have calculated that a global nuclear missile war could lead to dramatic environmental changes throughout the globe. As a result of hundreds and thousands of nuclear explosions, millions of tons of smoke and dust will be raised into the air to a height of 10-15 km, the sun's rays will not pass, a nuclear night will come, and then a nuclear winter for several years, plants will die, famine may come, everything will be covered with snow. In addition, the earth will be covered with long-lived radioactive fallout. Up to 1 billion people can die in the fire of a nuclear war, up to 2 billion - in a nuclear winter (Yu. M. Svirezhev, A. A. Baev and others).

Electromagnetic impulse and secondary damage factors. During nuclear explosions, due to the ionization of air and the movement of electrons at high speeds, electromagnetic fields arise that create pulsed electrical discharges and currents. An electromagnetic pulse generated in the atmosphere, like lightning, can induce strong currents in antennas, cables, power lines, wires, etc. The induced currents turn off automatic switches, can cause insulation failure, burnout of radio equipment and electrical appliances and electric shock to people. current. The radius of action of an electromagnetic pulse during air explosions with a capacity of 1 megaton is considered to be up to 32 km, with an explosion with a capacity of 10 megatons - up to 115 km.

Secondary damage factors include fires and explosions at chemical and oil refineries, which can cause mass poisoning of people with carbon monoxide or other toxic substances. The destruction of dams and hydraulic structures creates the danger of flood zones in settlements. To protect against secondary damage factors, engineering and technical measures should be taken to protect these structures.

It is necessary to know well the dangers posed by nuclear missile weapons and be able to properly organize the protection of troops and the population.

Explosive action, based on the use of intranuclear energy released during chain reactions of fission of heavy nuclei of some isotopes of uranium and plutonium or during thermonuclear reactions of fusion of hydrogen isotopes (deuterium and tritium) into heavier ones, for example, helium isogon nuclei. In thermonuclear reactions, energy is released 5 times more than in fission reactions (with the same mass of nuclei).

Nuclear weapons include various nuclear weapons, means of delivering them to the target (carriers) and controls.

Depending on the method of obtaining nuclear energy, ammunition is divided into nuclear (on fission reactions), thermonuclear (on fusion reactions), combined (in which energy is obtained according to the “fission - fusion - fission” scheme). The power of nuclear weapons is measured in TNT equivalent, t. a mass of explosive TNT, the explosion of which releases such an amount of energy as the explosion of a given nuclear bosiripas. TNT equivalent is measured in tons, kilotons (kt), megatons (Mt).

On fission reactions, ammunition with a capacity of up to 100 kt is designed, on fusion reactions - from 100 to 1000 kt (1 Mt). Combined munitions can be over 1 Mt. By power, nuclear weapons are divided into ultra-small (up to 1 kg), small (1-10 kt), medium (10-100 kt) and extra-large (more than 1 Mt).

Depending on the purpose of using nuclear weapons, nuclear explosions can be high-altitude (above 10 km), air (not more than 10 km), ground (surface), underground (underwater).

Damaging factors of a nuclear explosion

The main damaging factors of a nuclear explosion are: shock wave, light radiation of a nuclear explosion, penetrating radiation, radioactive contamination of the area and an electromagnetic pulse.

shock wave

Shockwave (SW)- an area of ​​sharply compressed air, spreading in all directions from the center of the explosion at supersonic speed.

Hot vapors and gases, trying to expand, produce a sharp blow to the surrounding layers of air, compress them to high pressures and densities and heat up to high temperatures (several tens of thousands of degrees). This layer of compressed air represents the shock wave. The front boundary of the compressed air layer is called the front of the shock wave. The SW front is followed by an area of ​​rarefaction, where the pressure is below atmospheric. Near the center of the explosion, the velocity of SW propagation is several times higher than the speed of sound. As the distance from the explosion increases, the wave propagation speed decreases rapidly. At large distances, its speed approaches the speed of sound in air.

The shock wave of an ammunition of medium power passes: the first kilometer in 1.4 s; the second - for 4 s; fifth - in 12 s.

The damaging effect of hydrocarbons on people, equipment, buildings and structures is characterized by: velocity pressure; overpressure in the shock front and the time of its impact on the object (compression phase).

The impact of HC on people can be direct and indirect. With direct exposure, the cause of injury is an instantaneous increase in air pressure, which is perceived as a sharp blow leading to fractures, damage to internal organs, and rupture of blood vessels. With indirect impact, people are amazed by flying debris of buildings and structures, stones, trees, broken glass and other objects. Indirect impact reaches 80% of all lesions.

With an overpressure of 20-40 kPa (0.2-0.4 kgf / cm 2), unprotected people can get light injuries (light bruises and concussions). The impact of SW with excess pressure of 40-60 kPa leads to lesions of moderate severity: loss of consciousness, damage to the hearing organs, severe dislocations of the limbs, damage to internal organs. Extremely severe lesions, often fatal, are observed at excess pressure over 100 kPa.

The degree of damage by a shock wave to various objects depends on the power and type of explosion, the mechanical strength (stability of the object), as well as on the distance at which the explosion occurred, the terrain and the position of objects on the ground.

To protect against the impact of hydrocarbons, one should use: trenches, cracks and trenches, which reduce its effect by 1.5-2 times; dugouts - 2-3 times; shelters - 3-5 times; basements of houses (buildings); terrain (forest, ravines, hollows, etc.).

light emission

light emission is a stream of radiant energy, including ultraviolet, visible and infrared rays.

Its source is a luminous area formed by hot explosion products and hot air. Light radiation propagates almost instantly and lasts, depending on the power of a nuclear explosion, up to 20 s. However, its strength is such that, despite its short duration, it can cause skin (skin) burns, damage (permanent or temporary) to the organs of vision of people, and ignition of combustible materials of objects. At the moment of formation of a luminous region, the temperature on its surface reaches tens of thousands of degrees. The main damaging factor of light radiation is a light pulse.

Light pulse - the amount of energy in calories falling per unit area of ​​the surface perpendicular to the direction of radiation, for the entire duration of the glow.

Attenuation of light radiation is possible due to its screening by atmospheric clouds, uneven terrain, vegetation and local objects, snowfall or smoke. So, a thick layer attenuates the light pulse by A-9 times, a rare one - by 2-4 times, and smoke (aerosol) screens - by 10 times.

To protect the population from light radiation, it is necessary to use protective structures, basements of houses and buildings, and the protective properties of the terrain. Any obstruction capable of creating a shadow protects against the direct action of light radiation and eliminates burns.

penetrating radiation

penetrating radiation- notes of gamma rays and neutrons emitted from the zone of a nuclear explosion. The time of its action is 10-15 s, the range is 2-3 km from the center of the explosion.

In conventional nuclear explosions, neutrons make up approximately 30%, in the explosion of neutron ammunition - 70-80% of the y-radiation.

The damaging effect of penetrating radiation is based on the ionization of cells (molecules) of a living organism, leading to death. Neutrons, in addition, interact with the nuclei of atoms of certain materials and can cause induced activity in metals and technology.

The main parameter characterizing penetrating radiation is: for y-radiation - the dose and dose rate of radiation, and for neutrons - the flux and flux density.

Permissible exposure doses to the population in wartime: single - within 4 days 50 R; multiple - within 10-30 days 100 R; during the quarter - 200 R; during the year - 300 R.

As a result of the passage of radiation through the materials of the environment, the intensity of the radiation decreases. The weakening effect is usually characterized by a layer of half attenuation, i.e. with. such a thickness of the material, passing through which the radiation is reduced by 2 times. For example, the intensity of the y-rays is reduced by 2 times: steel 2.8 cm thick, concrete - 10 cm, soil - 14 cm, wood - 30 cm.

Protective structures are used as protection against penetrating radiation, which weaken its impact from 200 to 5000 times. A pound layer of 1.5 m protects almost completely from penetrating radiation.

Radioactive contamination (contamination)

Radioactive contamination of the air, terrain, water area and objects located on them occurs as a result of the fallout of radioactive substances (RS) from the cloud of a nuclear explosion.

At a temperature of about 1700 ° C, the glow of the luminous region of a nuclear explosion stops and it turns into a dark cloud, to which a dust column rises (therefore, the cloud has a mushroom shape). This cloud moves in the direction of the wind, and RVs fall out of it.

The sources of radioactive substances in the cloud are the fission products of nuclear fuel (uranium, plutonium), the unreacted part of the nuclear fuel and radioactive isotopes formed as a result of the action of neutrons on the ground (induced activity). These RVs, being on contaminated objects, decay, emitting ionizing radiation, which in fact are the damaging factor.

The parameters of radioactive contamination are the dose of radiation (according to the impact on people) and the dose rate of radiation - the level of radiation (according to the degree of contamination of the area and various objects). These parameters are a quantitative characteristic of damaging factors: radioactive contamination during an accident with the release of radioactive substances, as well as radioactive contamination and penetrating radiation during a nuclear explosion.

On the terrain that has undergone radioactive contamination during a nuclear explosion, two sections are formed: the area of ​​​​the explosion and the trace of the cloud.

According to the degree of danger, the contaminated area along the trail of the explosion cloud is usually divided into four zones (Fig. 1):

Zone A- zone of moderate infection. It is characterized by a dose of radiation until the complete decay of radioactive substances at the outer boundary of the zone 40 rad and at the inner - 400 rad. The area of ​​zone A is 70-80% of the area of ​​the entire footprint.

Zone B- Highly contaminated area. The radiation doses at the boundaries are 400 rad and 1200 rad, respectively. The area of ​​zone B is approximately 10% of the area of ​​the radioactive trace.

Zone B- zone of dangerous infection. It is characterized by radiation doses at the borders of 1200 rad and 4000 rad.

Zone G- zone of extremely dangerous infection. Doses at the borders of 4000 rad and 7000 rad.

Rice. 1. Scheme of radioactive contamination of the area in the area of ​​a nuclear explosion and in the wake of the movement of the cloud

Radiation levels at the outer boundaries of these zones 1 hour after the explosion are 8, 80, 240, 800 rad/h, respectively.

Most of the radioactive fallout, causing radioactive contamination of the area, falls out of the cloud 10-20 hours after a nuclear explosion.

electromagnetic pulse

Electromagnetic pulse (EMP)- this is a combination of electric and magnetic fields resulting from the ionization of the atoms of the medium under the influence of gamma radiation. Its duration is a few milliseconds.

The main parameters of EMR are the currents and voltages induced in wires and cable lines, which can lead to damage and disable electronic equipment, and sometimes to damage to people working with the equipment.

During ground and air explosions, the damaging effect of an electromagnetic pulse is observed at a distance of several kilometers from the center of a nuclear explosion.

The most effective protection against an electromagnetic pulse is the shielding of power supply and control lines, as well as radio and electrical equipment.

The situation that develops during the use of nuclear weapons in the centers of destruction.

The focus of nuclear destruction is the territory within which, as a result of the use of nuclear weapons, mass destruction and death of people, farm animals and plants, destruction and damage to buildings and structures, utility and energy and technological networks and lines, transport communications and other objects occurred.

Zones of the focus of a nuclear explosion

To determine the nature of possible destruction, the volume and conditions for carrying out rescue and other urgent work, the nuclear lesion site is conditionally divided into four zones: complete, strong, medium and weak destruction.

Zone of complete destruction has an overpressure at the front of the shock wave of 50 kPa at the border and is characterized by massive irretrievable losses among the unprotected population (up to 100%), complete destruction of buildings and structures, destruction and damage to utility and energy and technological networks and lines, as well as parts of civil defense shelters, the formation of solid blockages in settlements. The forest is completely destroyed.

Zone of severe damage with overpressure at the front of the shock wave from 30 to 50 kPa is characterized by: massive irretrievable losses (up to 90%) among the unprotected population, complete and severe destruction of buildings and structures, damage to public utilities and technological networks and lines, the formation of local and continuous blockages in settlements and forests, the preservation of shelters and the majority of anti-radiation shelters of the basement type.

Medium damage zone with an excess pressure of 20 to 30 kPa is characterized by irretrievable losses among the population (up to 20%), medium and severe destruction of buildings and structures, the formation of local and focal blockages, continuous fires, the preservation of utility networks, shelters and most of the anti-radiation shelters.

Zone of weak damage with excess pressure from 10 to 20 kPa is characterized by weak and medium destruction of buildings and structures.

The focus of the lesion but the number of dead and injured can be commensurate with or exceed the lesion in an earthquake. So, during the bombing (bomb power up to 20 kt) of the city of Hiroshima on August 6, 1945, most of it (60%) was destroyed, and the death toll amounted to 140,000 people.

The personnel of economic facilities and the population entering the zones of radioactive contamination are exposed to ionizing radiation, which causes radiation sickness. The severity of the disease depends on the dose of radiation (irradiation) received. The dependence of the degree of radiation sickness on the magnitude of the radiation dose is given in Table. 2.

Table 2. Dependence of the degree of radiation sickness on the magnitude of the radiation dose

Under the conditions of hostilities with the use of nuclear weapons, vast territories may turn out to be in the zones of radioactive contamination, and the exposure of people may take on a mass character. In order to exclude overexposure of the personnel of facilities and the population in such conditions and to increase the stability of the functioning of objects of the national economy under conditions of radioactive contamination in wartime, permissible exposure doses are established. They make up:

• with a single irradiation (up to 4 days) - 50 rad;
• repeated irradiation: a) up to 30 days - 100 rad; b) 90 days - 200 rad;
• systematic exposure (during the year) 300 rad.

Caused by the use of nuclear weapons, the most complex. To eliminate them, disproportionately greater forces and means are needed than in the elimination of emergency situations in peacetime.

Nuclear weapons are one of the main types of weapons of mass destruction based on the use of intranuclear energy released during chain reactions of fission of heavy nuclei of some uranium and plutonium isotopes or during thermonuclear fusion reactions of light nuclei - hydrogen isotopes (deuterium and tritium).

As a result of the release of a huge amount of energy during an explosion, the damaging factors of nuclear weapons differ significantly from the action of conventional weapons. The main damaging factors of nuclear weapons: shock wave, light radiation, penetrating radiation, radioactive contamination, electromagnetic pulse.

Nuclear weapons include nuclear munitions, means of delivering them to the target (carriers) and controls.

The explosion power of a nuclear weapon is usually expressed in TNT equivalent, that is, the amount of conventional explosive (TNT), the explosion of which releases the same amount of energy.

The main parts of a nuclear weapon are: a nuclear explosive (NHE), a neutron source, a neutron reflector, an explosive charge, a detonator, and a body of the ammunition.

Damaging factors of a nuclear explosion

The shock wave is the main damaging factor in a nuclear explosion, since most of the destruction and damage to structures, buildings, as well as the defeat of people, are usually due to its impact. It is an area of ​​sharp compression of the medium, propagating in all directions from the explosion site at supersonic speed. The front boundary of the compressed air layer is called the front of the shock wave.

The damaging effect of the shock wave is characterized by the amount of excess pressure. Overpressure is the difference between the maximum pressure at the front of the shock wave and the normal atmospheric pressure in front of it.

With an excess pressure of 20-40 kPa, unprotected people can get light injuries (light bruises and concussions). The impact of a shock wave with an overpressure of 40-60 kPa leads to moderate injuries: loss of consciousness, damage to the hearing organs, severe dislocation of the limbs, bleeding from the nose and ears. Severe injuries occur when excess pressure exceeds 60 kPa. Extremely severe lesions are observed at excess pressure over 100 kPa.

Light radiation is a stream of radiant energy, including visible ultraviolet and infrared rays. Its source is a luminous area formed by hot explosion products and hot air. Light radiation propagates almost instantly and lasts, depending on the power of the nuclear explosion, up to 20 s. However, its strength is such that, despite its short duration, it can cause skin (skin) burns, damage (permanent or temporary) to the organs of vision of people, and ignition of combustible materials and objects.

Light radiation does not penetrate opaque materials, so any obstruction that can create a shadow protects against the direct action of light radiation and eliminates burns. Significantly attenuated light radiation in dusty (smoky) air, in fog, rain, snowfall.

Penetrating radiation is a stream of gamma rays and neutrons that propagates within 10-15 s. Passing through living tissue, gamma radiation and neutrons ionize the molecules that make up the cells. Under the influence of ionization, biological processes occur in the body, leading to a violation of the vital functions of individual organs and the development of radiation sickness. As a result of the passage of radiation through the materials of the environment, their intensity decreases. The weakening effect is usually characterized by a layer of half attenuation, that is, such a thickness of the material, passing through which, the radiation intensity is halved. For example, steel with a thickness of 2.8 cm, concrete - 10 cm, soil - 14 cm, wood - 30 cm are attenuated twice the intensity of gamma rays.

Open and especially closed slots reduce the impact of penetrating radiation, and shelters and anti-radiation shelters almost completely protect against it.

Radioactive contamination of the terrain, the surface layer of the atmosphere, air space, water and other objects occurs as a result of the fallout of radioactive substances from the cloud of a nuclear explosion. The significance of radioactive contamination as a damaging factor is determined by the fact that a high level of radiation can be observed not only in the area adjacent to the explosion site, but also at a distance of tens and even hundreds of kilometers from it. Radioactive contamination of the area can be dangerous for several weeks after the explosion.

Sources of radioactive radiation during a nuclear explosion are: fission products of nuclear explosives (Pu-239, U-235, U-238); radioactive isotopes (radionuclides) formed in soil and other materials under the influence of neutrons, that is, induced activity.

On the terrain that has undergone radioactive contamination during a nuclear explosion, two sections are formed: the area of ​​​​the explosion and the trace of the cloud. In turn, in the explosion area, windward and leeward sides are distinguished.

The teacher can briefly dwell on the characteristics of the zones of radioactive contamination, which, according to the degree of danger, are usually divided into the following four zones:

zone A - moderate infection area 70-80 % from the area of ​​the entire trace of the explosion. The radiation level at the outer boundary of the zone 1 hour after the explosion is 8 R/h;

zone B - severe infection, which accounts for approximately 10 % areas of the radioactive trace, radiation level 80 R/h;

zone B - dangerous infection. It occupies approximately 8-10% of the area of ​​the explosion cloud trace; radiation level 240 R/h;

zone G - extremely dangerous infection. Its area is 2-3% of the area of ​​the explosion cloud trace. Radiation level 800 R/h.

Gradually, the level of radiation on the ground decreases, approximately 10 times over time intervals that are multiples of 7. For example, 7 hours after the explosion, the dose rate decreases 10 times, and after 50 hours, almost 100 times.

The volume of air space in which radioactive particles are deposited from the explosion cloud and the upper part of the dust column is commonly called the cloud plume. As the plume approaches the object, the radiation level increases due to the gamma radiation of radioactive substances contained in the plume. Fallout of radioactive particles is observed from the plume, which, falling on various objects, infect them. The degree of contamination by radioactive substances of the surfaces of various objects, people's clothing and skin is usually judged by the dose rate (radiation level) of gamma radiation near contaminated surfaces, determined in milliroentgens per hour (mR / h).

Another damaging factor of a nuclear explosion is electromagnetic impulse. This is a short-term electromagnetic field that occurs during the explosion of a nuclear weapon as a result of the interaction of gamma rays and neutrons emitted during a nuclear explosion with the atoms of the environment. The consequence of its impact may be a burnout or breakdown of individual elements of radio-electronic and electrical equipment.

The most reliable means of protection against all damaging factors of a nuclear explosion are protective structures. In open areas and in the field, you can use durable local objects, reverse slopes of heights and terrain folds for shelter.

When operating in contaminated areas, to protect the respiratory organs, eyes and open areas of the body from radioactive substances, it is necessary, if possible, to use gas masks, respirators, anti-dust fabric masks and cotton-gauze bandages, as well as skin protection equipment, including clothing.

Chemical weapons, ways to protect against them

Chemical weapon- a weapon of mass destruction, the action of which is based on the toxic properties of chemicals. The main components of chemical weapons are chemical warfare agents and their means of use, including carriers, instruments and control devices used to deliver chemical munitions to targets. Chemical weapons were prohibited by the 1925 Geneva Protocol. Currently, the world is taking measures to completely ban chemical weapons. However, it is still available in a number of countries.

Chemical weapons include toxic substances (0V) and means of their use. Rockets, aerial bombs, artillery shells and mines are loaded with toxic substances.

According to the effect on the human body, 0V are divided into nerve-paralytic, blistering, asphyxiating, general poisonous, irritating and psychochemical.

0V nerve agent: VX (VX), sarin. They affect the nervous system when acting on the body through the respiratory organs, when penetrating in a vaporous and drop-liquid state through the skin, as well as when entering the gastrointestinal tract along with food and water. Their resistance in the summer is more than a day, in the winter for several weeks and even months. These 0V are the most dangerous. A very small amount of them is enough to defeat a person.

Signs of damage are: salivation, constriction of the pupils (miosis), difficulty breathing, nausea, vomiting, convulsions, paralysis.

A gas mask and protective clothing are used as personal protective equipment. To provide first aid to the affected person, they put on a gas mask and inject him with a syringe tube or by taking an antidote tablet. If 0V nerve agent gets on the skin or clothing, the affected areas are treated with liquid from an individual anti-chemical package (IPP).

0V blister action (mustard gas). They have a multilateral damaging effect. In the drop-liquid and vapor state, they affect the skin and eyes, when inhaled vapors - the respiratory tract and lungs, when ingested with food and water - the digestive organs. A characteristic feature of mustard gas is the presence of a period of latent action (the lesion is not detected immediately, but after a while - 2 hours or more). Signs of damage are reddening of the skin, the formation of small blisters, which then merge into large ones and burst after two or three days, turning into difficult-to-heal ulcers. With any local damage, 0V causes a general poisoning of the body, which manifests itself in fever, malaise.

In conditions of application of 0V blistering action, it is necessary to be in a gas mask and protective clothing. If drops of 0V get on the skin or clothing, the affected areas are immediately treated with liquid from the IPP.

0V suffocating action (fausten). They act on the body through the respiratory system. Signs of defeat are a sweetish, unpleasant aftertaste in the mouth, cough, dizziness, general weakness. These phenomena disappear after leaving the source of infection, and the victim feels normal within 4-6 hours, unaware of the lesion. During this period (latent action) pulmonary edema develops. Then breathing may deteriorate sharply, a cough with copious sputum, headache, fever, shortness of breath, and palpitations may appear.

In case of damage, a gas mask is put on the victim, they take him out of the infected area, cover him warmly and provide him with peace.

In no case should you give the victim artificial respiration!

0V of general toxic action (hydrocyanic acid, cyanogen chloride). They affect only when inhaling air contaminated by their vapors (they do not act through the skin). Signs of damage are a metallic taste in the mouth, throat irritation, dizziness, weakness, nausea, severe convulsions, paralysis. To protect against these 0V, it is enough to use a gas mask.

To assist the victim, it is necessary to crush the ampoule with the antidote, introduce it under the helmet-mask of the gas mask. In severe cases, the victim is given artificial respiration, warmed up and sent to a medical center.

0B irritant: CS (CS), adameite, etc. Cause acute burning and pain in the mouth, throat and eyes, severe lacrimation, cough, difficulty breathing.

0V psychochemical action: BZ (B-Z). They act specifically on the central nervous system and cause mental (hallucinations, fear, depression) or physical (blindness, deafness) disorders.

In case of damage to 0V irritating and psychochemical effects, it is necessary to treat the infected areas of the body with soapy water, rinse the eyes and nasopharynx thoroughly with clean water, and shake out the uniform or brush it. Victims should be removed from the infected area and given medical attention.

The main ways to protect the population is to shelter it in protective structures and provide the entire population with personal and medical protection equipment.

Shelters and anti-radiation shelters (RSH) can be used to shelter the population from chemical weapons.

When characterizing personal protective equipment (PPE), indicate that they are intended to protect against ingestion of toxic substances into the body and onto the skin. According to the principle of operation, PPE is divided into filtering and insulating. According to the purpose, PPE is divided into respiratory protection equipment (filtering and insulating gas masks, respirators, anti-dust fabric masks) and skin protection equipment (special insulating clothing, as well as ordinary clothing).

Further indicate that medical protective equipment is intended for the prevention of damage by toxic substances and the provision of first aid to the victim. The individual first-aid kit (AI-2) includes a set of medicines intended for self-help and mutual assistance in the prevention and treatment of chemical weapons injuries.

An individual dressing bag is designed for degassing 0V in open areas of the skin.

In conclusion of the lesson, it should be noted that the duration of the damaging effect of 0V is the shorter, the stronger the wind and ascending air currents. In forests, parks, ravines and on narrow streets, 0V persists longer than in open areas.

The concept of weapons of mass destruction. History of creation.

In 1896, the French physicist A. Becquerel discovered the phenomenon of radioactivity. It marked the beginning of the era of the study and use of nuclear energy. But in the beginning, not nuclear power plants, not spaceships, not powerful icebreakers appeared, but weapons of monstrous destructive power. It was created in 1945 by physicists who fled before the start of World War II from Nazi Germany to the United States and supported by the government of this country, led by Robert Oppenheimer.

The first atomic explosion took place July 16, 1945. This happened in the Jornada del Muerto desert of New Mexico at the training ground of the American air base Alamagordo.

August 6, 1945 - over the city of Hiroshima appeared three am. aircraft, including a bomber carrying a 12.5 kt atomic bomb with the name "Kid". The fireball formed after the explosion had a diameter of 100m, the temperature at its center reached 3000 degrees. Houses collapsed with terrible force, they caught fire within a radius of 2 km. People near the epicenter literally evaporated. After 5 minutes, a dark gray cloud with a diameter of 5 km hung over the city center. A white cloud escaped from it, quickly reaching a height of 12 km and acquiring the shape of a mushroom. Later, a cloud of dirt, dust, ash descended on the city, containing radioactive isotopes. Hiroshima burned for 2 days.

Three days after the bombing of Hiroshima, on August 9, her fate was to be shared by the city of Kokura. But due to bad weather conditions, the city of Nagasaki became a new victim. An atom bomb with a power of 22 kt was dropped on it. (fat man). The city was half destroyed, saved the terrain. According to the UN, 78 tons were killed in Hiroshima. people, in Nagasaki - 27 thousand.

Nuclear weapon explosive weapons of mass destruction. It is based on the use of intranuclear energy released during chain nuclear fission reactions of heavy nuclei of some isotopes of uranium and plutonium or during thermonuclear fusion reactions of light nuclei - hydrogen isotopes (deuterium and tritium). These weapons include various nuclear weapons, means of controlling them and delivering them to the target (missiles, aircraft, artillery). In addition, nuclear weapons are made in the form of mines (land mines). It is the most powerful type of weapon of mass destruction and is capable of incapacitating a large number of people in a short time. The massive use of nuclear weapons is fraught with catastrophic consequences for all mankind.

Damage nuclear explosion depends on:

* ammunition charge power, * type of explosion

Power nuclear weapon is characterized TNT equivalent, i.e., the mass of TNT, the explosion energy of which is equivalent to the explosion energy of a given nuclear weapon, and is measured in tons, thousands, millions of tons. In terms of power, nuclear weapons are divided into ultra-small, small, medium, large and extra-large.

Types of explosions

The point where the explosion occurred is called center, and its projection on the surface of the earth (water) the epicenter of a nuclear explosion.

The damaging factors of a nuclear explosion.

* shockwave - 50%

* light radiation - 35%

* penetrating radiation - 5%

* radioactive contamination

* electromagnetic impulse - 1%

shock wave is an area of ​​sharp compression of the air environment, spreading in all directions from the explosion site at supersonic speed (more than 331 m/s). The front boundary of the compressed air layer is called the front of the shock wave. The shock wave, which is formed in the early stages of the existence of an explosion cloud, is one of the main damaging factors of an atmospheric nuclear explosion.

shock wave- distributes its energy over the entire volume it has passed, so its strength decreases in proportion to the cube root of the distance.

The shock wave destroys buildings, structures and affects unprotected people. Damage caused by a shock wave directly to a person is divided into light, medium, severe and extremely severe.

The speed of movement and the distance over which the shock wave propagates depend on the power of the nuclear explosion; as the distance from the explosion increases, the speed drops rapidly. Thus, during the explosion of a munition with a capacity of 20 kt, the shock wave travels 1 km in 2 seconds, 2 km in 5 seconds, 3 km in 8 seconds. During this time, a person after a flash can take cover and thereby avoid being hit by a shock wave.

The degree of shock wave damage to various objects depends on the power and type of explosion, mechanical strength(stability of the object), as well as from the distance at which the explosion occurred, the terrain and the position of objects on her.

Protection folds of the terrain, shelters, basement structures can serve as a shock wave.

light emission- this is a stream of radiant energy (a stream of light rays emanating from a fireball), including visible, ultraviolet and infrared rays. It is formed by hot products of a nuclear explosion and hot air, spreads almost instantly and lasts, depending on the power of a nuclear explosion, up to 20 seconds. During this time, its intensity can exceed 1000 W/cm2 (the maximum intensity of sunlight is 0.14 W/cm2).

Light radiation is absorbed by opaque materials and can cause massive fires of buildings and materials, as well as skin burns (the degree depends on the power of the bomb and the distance from the epicenter) and eye damage (damage to the cornea due to the thermal effect of light and temporary blindness in which a person loses sight for a period of several seconds to several hours.More severe retinal damage occurs when a person's gaze is directed directly at the fireball of the explosion.The brightness of the fireball does not change with distance (except in the case of fog), just its apparent size decreases.Thus, damage the eyes at almost any distance that the flash can be seen (this is more likely at night due to the wider pupil opening). The range of propagation of light radiation is highly dependent on weather conditions. Cloudiness, smoke, dust greatly reduce the effective radius of its action.

In almost all cases, the emission of light radiation from the explosion region ends by the time the shock wave arrives. This is violated only in the area of ​​​​total destruction, where any of the three factors (light, radiation, shock wave) causes lethal damage.

light emission, like any light, it does not pass through opaque materials, so they are suitable for shelter from it any object that creates a shadow. The degree of damaging effect of light radiation is sharply reduced under the condition of timely notification of people, the use of protective structures, natural shelters (especially forests and relief folds), personal protective equipment (protective clothing, goggles) and strict implementation of fire prevention measures.

penetrating radiation represents flux of gamma quanta (rays) and neutrons emitted from the area of ​​a nuclear explosion for several seconds . Gamma quanta and neutrons propagate in all directions from the center of the explosion. Due to the very strong absorption in the atmosphere, penetrating radiation affects people only at a distance of 2-3 km from the explosion site, even for large charges. As the distance from the explosion increases, the number of gamma quanta and neutrons passing through a unit surface decreases. During underground and underwater nuclear explosions, the effect of penetrating radiation extends over distances that are much shorter than during ground and air explosions, which is explained by the absorption of the neutron flux and gamma quanta by earth and water.

The damaging effect of penetrating radiation is determined by the ability of gamma quanta and neutrons to ionize the atoms of the medium in which they propagate. Passing through living tissue, gamma quanta and neutrons ionize the atoms and molecules that make up cells, which lead to disruption of the vital functions of individual organs and systems. Under the influence of ionization, biological processes of cell death and decomposition occur in the body. As a result, affected people develop a specific disease called radiation sickness.

To assess the ionization of the atoms of the medium, and, consequently, the damaging effect of penetrating radiation on a living organism, the concept radiation doses (or radiation doses), unit of measure which is x-ray (R). A radiation dose of 1R corresponds to the formation of approximately 2 billion pairs of ions in one cubic centimeter of air.

Depending on the dose of radiation, there are four degrees of radiation sickness. The first (mild) occurs when a person receives a dose of 100 to 200 R. It is characterized by general weakness, mild nausea, short-term dizziness, increased sweating; personnel receiving such a dose usually do not fail. The second (middle) degree of radiation sickness develops when receiving a dose of 200-300 R; in this case, the signs of damage - headache, fever, gastrointestinal upset - appear more sharply and quickly, the personnel in most cases fail. The third (severe) degree of radiation sickness occurs at a dose of more than 300-500 R; it is characterized by severe headaches, nausea, severe general weakness, dizziness and other ailments; the severe form is often fatal. A dose of radiation above 500 R causes radiation sickness of the fourth degree and is usually considered fatal for a person.

Protection against penetrating radiation is provided by various materials that attenuate the flux of gamma and neutron radiation. The degree of attenuation of penetrating radiation depends on the properties of the materials and the thickness of the protective layer.

The weakening effect is usually characterized by a layer of half attenuation, that is, such a thickness of the material, passing through which the radiation is halved. For example, the intensity of gamma rays is halved: steel 2.8 cm thick, concrete - 10 cm, soil - 14 cm, wood - 30 cm (determined by the density of the material).

radioactive contamination

Radioactive contamination of people, military equipment, terrain and various objects during a nuclear explosion is caused by fission fragments of the charge substance (Pu-239, U-235, U-238) and the unreacted part of the charge falling out of the explosion cloud, as well as induced radioactivity. Over time, the activity of fission fragments rapidly decreases, especially in the first hours after the explosion. So, for example, the total activity of fission fragments in the explosion of a nuclear weapon with a power of 20 kT in one day will be several thousand times less than one minute after the explosion.

During the explosion of a nuclear weapon, part of the substance of the charge does not undergo fission, but falls out in its usual form; its decay is accompanied by the formation of alpha particles. Induced radioactivity is due to radioactive isotopes (radionuclides) formed in the soil as a result of its irradiation with neutrons emitted at the time of the explosion by the nuclei of atoms of chemical elements that make up the soil. The resulting isotopes, as a rule, are beta-active, the decay of many of them is accompanied by gamma radiation. The half-lives of most of the resulting radioactive isotopes are relatively short - from one minute to an hour. In this regard, the induced activity can be dangerous only in the first hours after the explosion and only in the area close to the epicenter.

Most of the long-lived isotopes are concentrated in the radioactive cloud that forms after the explosion. The height of cloud rise for a munition with a power of 10 kT is 6 km, for a munition with a power of 10 MgT it is 25 km. As the cloud moves, first the largest particles fall out of it, and then smaller and smaller particles, forming a zone of radioactive contamination along the way, the so-called cloud trail. The size of the trace depends mainly on the power of the nuclear weapon, as well as on the speed of the wind, and can be several hundred kilometers long and several tens of kilometers wide.

The degree of radioactive contamination of the area is characterized by the level of radiation for a certain time after the explosion. The level of radiation is called exposure dose rate(R/h) at a height of 0.7-1 m above the infected surface.

The emerging zones of radioactive contamination according to the degree of danger are usually divided into the following four zones.

Zone G- extremely dangerous infection. Its area is 2-3% of the area of ​​the explosion cloud trace. The radiation level is 800 R/h.

Zone B- dangerous infection. It occupies approximately 8-10% of the area of ​​the explosion cloud trace; radiation level 240 R/h.

Zone B- severe contamination, which accounts for approximately 10% of the area of ​​the radioactive trace, the radiation level is 80 R/h.

Zone A- moderate contamination with an area of ​​70-80% of the area of ​​the entire trace of the explosion. The radiation level at the outer boundary of the zone 1 hour after the explosion is 8 R/h.

Losses as a result internal exposure appear due to the ingress of radioactive substances into the body through the respiratory system and the gastrointestinal tract. In this case, radioactive radiation comes into direct contact with the internal organs and can cause severe radiation sickness; the nature of the disease will depend on the amount of radioactive substances that have entered the body.

Radioactive substances do not have a harmful effect on armament, military equipment and engineering structures.

electromagnetic pulse

Nuclear explosions in the atmosphere and in higher layers lead to powerful electromagnetic fields. Due to their short-term existence, these fields are usually called an electromagnetic pulse (EMP).

The damaging effect of electromagnetic radiation is due to the occurrence of voltages and currents in conductors of various lengths located in the air, equipment, on the ground or on other objects. The effect of EMR is manifested primarily in relation to electronic equipment, where, under the action of EMR, voltages are also induced that can cause breakdown of electrical insulation, damage to transformers, combustion of spark gaps, damage to semiconductor devices and other elements of radio engineering devices. Communication, signaling and control lines are the most exposed to EMI. Strong electromagnetic fields can damage electrical circuits and interfere with the operation of unshielded electrical equipment.

A high-altitude explosion can interfere with communications over very large areas. EMI protection is achieved by shielding power supply lines and equipment.

The focus of nuclear destruction

The focus of nuclear damage is the territory where, under the influence of the damaging factors of a nuclear explosion, destruction of buildings and structures, fires, radioactive contamination of the area and damage to the population occur. The simultaneous impact of a shock wave, light radiation and penetrating radiation largely determines the combined nature of the destructive effect of a nuclear munition explosion on people, military equipment and structures. In case of combined damage to people, injuries and contusions from exposure to a shock wave can be combined with burns from light radiation with simultaneous ignition from light radiation. Radio-electronic equipment and devices, in addition, may lose their operability as a result of exposure to an electromagnetic pulse (EMP).

The size of the source is the larger, the more powerful the nuclear explosion. The nature of destruction in the hearth also depends on the strength of the structures of buildings and structures, their number of storeys and building density.

For the outer boundary of the source of nuclear damage, a conditional line on the ground is taken, drawn at such a distance from the epicenter of the explosion, where the value of the excess pressure of the shock wave is 10 kPa.

3.2. nuclear explosions

3.2.1. Classification of nuclear explosions

Nuclear weapons were developed in the United States during World War II mainly by the efforts of European scientists (Einstein, Bohr, Fermi, and others). The first test of this weapon took place in the United States at the Alamogordo training ground on July 16, 1945 (at that time the Potsdam Conference was taking place in defeated Germany). And only 20 days later, on August 6, 1945, an atomic bomb of enormous power for that time - 20 kilotons - was dropped on the Japanese city of Hiroshima without any military necessity and expediency. Three days later, on August 9, 1945, the second Japanese city, Nagasaki, was subjected to atomic bombing. The consequences of nuclear explosions were terrible. In Hiroshima, out of 255 thousand inhabitants, almost 130 thousand people were killed or injured. Of the almost 200 thousand inhabitants of Nagasaki, more than 50 thousand people were struck.

Then nuclear weapons were manufactured and tested in the USSR (1949), Great Britain (1952), France (1960), and China (1964). Now more than 30 states of the world are ready in scientific and technical terms for the production of nuclear weapons.

Now there are nuclear charges that use the fission reaction of uranium-235 and plutonium-239 and thermonuclear charges that use (during the explosion) a fusion reaction. When one neutron is captured, the uranium-235 nucleus is divided into two fragments, releasing gamma quanta and two more neutrons (2.47 neutrons for uranium-235 and 2.91 neutrons for plutonium-239). If the mass of uranium is more than a third, then these two neutrons divide two more nuclei, releasing four neutrons already. After the fission of the next four nuclei, eight neutrons are released, and so on. There is a chain reaction that leads to a nuclear explosion.

Classification of nuclear explosions:

By charge type:

- nuclear (atomic) - fission reaction;

- thermonuclear - fusion reaction;

- neutron - a large flux of neutrons;

- combined.

By appointment:

Test;

For peaceful purposes;

- for military purposes;

By power:

- ultra-small (less than 1 thousand tons of TNT);

- small (1 - 10 thousand tons);

- medium (10-100 thousand tons);

- large (100 thousand tons -1 Mt);

- super-large (over 1 Mt).

Type of explosion:

- high-altitude (over 10 km);

- air (light cloud does not reach the surface of the Earth);

ground;

Surface;

Underground;

Underwater.

The damaging factors of a nuclear explosion. The damaging factors of a nuclear explosion are:

- shock wave (50% of the energy of the explosion);

- light radiation (35% of the energy of the explosion);

- penetrating radiation (45% of the energy of the explosion);

- radioactive contamination (10% of the energy of the explosion);

- electromagnetic pulse (1% of the energy of the explosion);

Shockwave (UX) (50% of the energy of the explosion). VX is a zone of strong air compression, which propagates at supersonic speed in all directions from the center of the explosion. The source of the shock wave is the high pressure in the center of the explosion, which reaches 100 billion kPa. The explosion products, as well as very heated air, expand and compress the surrounding air layer. This compressed layer of air compresses the next layer. In this way, pressure is transferred from one layer to another, creating VX. The front line of compressed air is called the VX front.

The main parameters of the UH are:

- overpressure;

- speed head;

- duration of the shock wave.

Excess pressure is the difference between the maximum pressure in the VX front and atmospheric pressure.

G f \u003d G f.max -P 0

It is measured in kPa or kgf / cm 2 (1 agm \u003d 1.033 kgf / cm 2 \u003d \u003d 101.3 kPa; 1 atm \u003d 100 kPa).

The value of overpressure mainly depends on the power and type of explosion, as well as on the distance to the center of the explosion.

It can reach 100 kPa in explosions with a power of 1 mt or more.

Excess pressure decreases rapidly with distance from the epicenter of the explosion.

High-speed air pressure is a dynamic load that creates an air flow, denoted by P, measured in kPa. The magnitude of the velocity head of the air depends on the velocity and density of the air behind the wave front and is closely related to the value of the maximum overpressure of the shock wave. Velocity pressure noticeably acts at an excess pressure of more than 50 kPa.

The duration of the shock wave (overpressure) is measured in seconds. The longer the action time, the greater the damaging effect of the UV. The ultraviolet of a nuclear explosion of medium power (10-100 kt) travels 1000 m in 1.4 s, 2000 m in 4 s; 5000 m - in 12 s. VX strikes people and destroys buildings, structures, objects and communication equipment.

The shock wave affects unprotected people directly and indirectly (indirect damage is damage that is inflicted on a person by fragments of buildings, structures, glass fragments and other objects that move at high speed under the action of high-speed air pressure). Injuries that occur as a result of the action of a shock wave are divided into:

- light, characteristic of the RF = 20 - 40 kPa;

- /span> average, characteristic for RF=40 - 60 kPa:

- heavy, characteristic for RF=60 - 100 kPa;

- very heavy, characteristic of RF above 100 kPa.

With an explosion with a power of 1 Mt, unprotected people can receive minor injuries, being 4.5 - 7 km from the epicenter of the explosion, severe - 2 - 4 km each.

To protect against UV, special storage facilities are used, as well as basements, underground workings, mines, natural shelters, terrain folds, etc.

The volume and nature of the destruction of buildings and structures depends on the power and type of explosion, the distance from the epicenter of the explosion, the strength and size of buildings and structures. Of the ground buildings and structures, the most resistant are monolithic reinforced concrete structures, houses with a metal frame and buildings of anti-seismic construction. In a nuclear explosion with a power of 5 Mt, reinforced concrete structures will be destroyed within a radius of 6.5 km, brick houses - up to 7.8 km, wooden houses will be completely destroyed within a radius of 18 km.

UV tends to penetrate into rooms through window and door openings, causing destruction of partitions and equipment. Technological equipment is more stable and is destroyed mainly as a result of the collapse of walls and ceilings of houses in which it is installed.

Light radiation (35% of the energy of the explosion). Light radiation (CB) is electromagnetic radiation in the ultraviolet, visible and infrared regions of the spectrum. The source of SW is a luminous region that propagates at the speed of light (300,000 km/s). The time of existence of the luminous region depends on the power of the explosion and is for charges of various calibers: super-small caliber - tenths of a second, medium - 2 - 5 s, super-large - several tens of seconds. The size of the luminous area for the over-small caliber is 50-300 m, for the medium caliber 50-1000 m, for the extra-large caliber it is several kilometers.

The main parameter characterizing SW is the light pulse. It is measured in calories per 1 cm 2 of the surface located perpendicular to the direction of direct radiation, as well as in kilojoules per m 2:

1 cal / cm 2 \u003d 42 kJ / m 2.

Depending on the magnitude of the perceived light pulse and the depth of the skin lesion, a person experiences burns of three degrees:

- I degree burns are characterized by redness of the skin, swelling, soreness, caused by a light pulse of 100-200 kJ/m 2 ;

- second degree burns (blisters) occur with a light pulse of 200 ... 400 kJ / m 2;

- third degree burns (ulcers, skin necrosis) appear at a light pulse of 400-500 kJ/m 2 .

A large impulse value (more than 600 kJ/m2) causes charring of the skin.

During a nuclear explosion, 20 kt of guardianship I degree will be observed within a radius of 4.0 km., 11 degree - within 2.8 kt, III degree - within a radius of 1.8 km.

With an explosion power of 1 Mt, these distances increase to 26.8 km., 18.6 km., and 14.8 km. respectively.

SW propagates in a straight line and does not pass through opaque materials. Therefore, any obstacle (wall, forest, armor, thick fog, hills, etc.) is able to form a shadow zone, protects from light radiation.

Fires are the strongest effect of SW. The size of fires is influenced by factors such as the nature and condition of the development.

With a building density of more than 20%, fires can merge into one continuous fire.

Losses from the fire of World War II amounted to 80%. During the well-known bombardment of Hamburg, 16,000 houses were fired at the same time. The temperature in the fire area reached 800°C.

CB significantly enhances the action of HC.

Penetrating radiation (45% of the energy of the explosion) is caused by the radiation and neutron flux that propagate for several kilometers around a nuclear explosion, ionizing the atoms of this medium. The degree of ionization depends on the dose of radiation, the unit of measurement of which is the roentgen (in 1 cm of dry air at a temperature and pressure of 760 mm Hg, about two billion pairs of ions are formed). The ionizing ability of neutrons is estimated in environmental equivalents of X-rays (Rem - the dose of neutrons, the effect of which is equal to the influential X-ray radiation).

The effect of penetrating radiation on people causes radiation sickness in them. Radiation sickness of the 1st degree (general weakness, nausea, dizziness, sleepiness) develops mainly at a dose of 100-200 rad.

Radiation sickness II degree (vomiting, severe headache) occurs at a dose of 250-400 tips.

Radiation sickness III degree (50% die) develops at a dose of 400 - 600 rad.

Radiation sickness IV degree (mostly death occurs) occurs when more than 600 tips are irradiated.

In nuclear explosions of low power, the influence of penetrating radiation is more significant than that of UV and light irradiation. With an increase in the power of the explosion, the relative proportion of penetrating radiation injuries decreases, as the number of injuries and burns increases. The radius of damage by penetrating radiation is limited to 4 - 5 km. regardless of the increase in explosive power.

Penetrating radiation significantly affects the efficiency of radio electronic equipment and communication systems. Pulsed radiation, neutron flux disrupt the functioning of many electronic systems, especially those that operate in a pulsed mode, causing interruptions in power supply, short circuits in transformers, voltage increase, distortion of the shape and magnitude of electrical signals.

In this case, the radiation causes temporary interruptions in the operation of the equipment, and the neutron flux causes irreversible changes.

For diodes with a flux density of 1011 (germanium) and 1012 (silicon) neutrons/em 2, the characteristics of the forward and reverse currents change.

In transistors, the current amplification factor decreases and the reverse collector current increases. Silicon transistors are more stable and retain their reinforcing properties at neutron fluxes above 1014 neutrons/cm 2 .

Electrovacuum devices are stable and retain their properties up to a flux density of 571015 - 571016 neutrons/cm 2 .

Resistors and capacitors resistant to a density of 1018 neutrons / cm 2. Then the conductivity of the resistors changes, the leakage and losses of the capacitors increase, especially for electric capacitors.

Radioactive contamination (up to 10% of the energy of a nuclear explosion) occurs through induced radiation, the fallout to the ground of fission fragments of a nuclear charge and part of the residual uranium-235 or plutonium-239.

Radioactive contamination of the area is characterized by the level of radiation, which is measured in roentgens per hour.

The fallout of radioactive substances continues when the radioactive cloud moves under the influence of wind, as a result of which a radioactive trace is formed on the surface of the earth in the form of a strip of contaminated terrain. The length of the trail can reach several tens of kilometers and even hundreds of kilometers, and the width - tens of kilometers.

Depending on the degree of infection and the possible consequences of exposure, 4 zones are distinguished: moderate, severe, dangerous and extremely dangerous infection.

For the convenience of solving the problem of assessing the radiation situation, the boundaries of the zones are usually characterized by radiation levels at 1 hour after the explosion (P a) and 10 hours after the explosion, P 10 . The values ​​of doses of gamma radiation D are also set, which are received over a period of 1 hour after the explosion until the complete decay of radioactive substances.

Zone of moderate infection (zone A) - D = 40.0-400 rad. The level of radiation at the outer boundary of the zone Г в = 8 R/h, Р 10 = 0.5 R/h. In zone A, work on objects, as a rule, does not stop. In open areas located in the middle of the zone or at its inner border, work is stopped for several hours.

Zone of severe infection (zone B) - D = 4000-1200 tips. The level of radiation at the outer border G in \u003d 80 R / h., P 10 \u003d 5 R / h. Work stops for 1 day. People are hiding in shelters or evacuating.

Zone of dangerous infection (zone B) - D \u003d 1200 - 4000 rad. The level of radiation at the outer border G in \u003d 240 R / h., R 10 \u003d 15 R / h. In this zone, work at the facilities stops from 1 to 3-4 days. People are evacuated or take shelter in protective structures.

The zone of extremely dangerous infection (zone G) on the outer border D = 4000 rad. Radiation levels G in \u003d 800 R / h., R 10 \u003d 50 R / h. Work stops for several days and resumes after the fall in radiation levels to a safe value.

For an example in fig. 23 shows the sizes of zones A, B, C, D, which are formed during an explosion with a power of 500 kt and a wind speed of 50 km/h.

A characteristic feature of radioactive contamination during nuclear explosions is the relatively rapid decline in radiation levels.

The height of the explosion has a great influence on the nature of the infection. During high-altitude explosions, the radioactive cloud rises to a considerable height, is blown away by the wind, and disperses over a large area.

Table

The dependence of the level of radiation on time after the explosion

Time after explosion, h

Radiation level, %

The stay of people in contaminated areas causes them to be exposed to radioactive substances. In addition, radioactive particles can enter the body, settle in open areas of the body, penetrate the blood through wounds, scratches, causing one or another degree of radiation sickness.

For wartime conditions, the following doses are considered a safe dose of total single exposure: within 4 days - no more than 50 tips, 10 days - no more than 100 tips, 3 months - 200 tips, for a year - no more than 300 rads.

Personal protective equipment is used to work in the contaminated area, decontamination is carried out when leaving the contaminated area, and people are subject to sanitization.

Shelters and shelters are used to protect people. Each building is evaluated by the attenuation coefficient K condition, which is understood as a number indicating how many times the radiation dose in the storage facility is less than the radiation dose in open areas. For stone houses To dishes - 10, cars - 2, tanks - 10, cellars - 40, for specially equipped storage facilities it can be even larger (up to 500).

An electromagnetic pulse (EMI) (1% of the energy of the explosion) is a short-term surge in the voltage of electric and magnetic fields and currents due to the movement of electrons from the center of the explosion, resulting from the ionization of air. The amplitude of the EMI decreases exponentially very quickly. The pulse duration is equal to a hundredth of a microsecond (Fig. 25). After the first pulse, due to the interaction of electrons with the Earth's magnetic field, a second, longer pulse occurs.

The EMR frequency range is up to 100 m Hz, but its energy is mainly distributed near the mid-frequency range of 10-15 kHz. The damaging effect of EMI is several kilometers from the center of the explosion. Thus, in a ground explosion with a power of 1 Mt, the vertical component of the electric field EMI at a distance of 2 km. from the center of the explosion - 13 kV / m, at 3 km - 6 kV / m, 4 km - 3 kV / m.

EMI does not directly affect the human body.

When evaluating the impact on electronic equipment by EMI, the simultaneous exposure to EMI radiation must also be taken into account. Under the influence of radiation, the conductivity of transistors, microcircuits increases, and under the influence of EMI, they break through. EMI is an extremely effective tool for damaging electronic equipment. The SDI program provides for the conduct of special explosions, which create EMI sufficient to destroy electronics.

Time: 0 s Distance: 0 m (exactly at the epicenter).
Initiation of the explosion of a nuclear detonator.

Time:0.0000001 c. Distance: 0 m. Temperature: up to 100 million °C.
The beginning and course of nuclear and thermonuclear reactions in a charge. With its explosion, a nuclear detonator creates the conditions for the start of thermonuclear reactions: the thermonuclear combustion zone passes as a shock wave in the charge substance at a speed of about 5000 km / s (10 6 -10 7 m / s). About 90% of the neutrons released during the reactions are absorbed by the bomb material, the remaining 10% fly out.

Time:10 −7 s. Distance: 0 m.
Up to 80% or more of the energy of the reactant is transformed and released in the form of soft X-ray and hard UV radiation with great energy. The X-rays form a heat wave that heats up the bomb, escapes and begins to heat the surrounding air.

Time:
The end of the reaction, the beginning of the expansion of the bomb substance. The bomb immediately disappears from sight, and a bright luminous sphere (fireball) appears in its place, masking the spread of the charge. The growth rate of the sphere in the first meters is close to the speed of light. The density of the substance here drops to 1% of the density of the surrounding air in 0.01 s; the temperature drops to 7-8 thousand °C in 2.6 s, it is held for ~5 seconds and further decreases with the rise of the fiery sphere; pressure after 2-3 s drops to slightly below atmospheric.

Time: 1.1×10 −7 s. Distance: 10 m. Temperature: 6 million °C.
The expansion of the visible sphere up to ~10 m is due to the glow of ionized air under the X-ray radiation of nuclear reactions, and then through the radiative diffusion of the heated air itself. The energy of radiation quanta leaving the thermonuclear charge is such that their free path before being captured by air particles is on the order of 10 m, and is initially comparable to the size of a sphere; photons quickly run around the entire sphere, averaging its temperature and fly out of it at the speed of light, ionizing more and more new layers of air; hence the same temperature and near-light growth rate. Further, from capture to capture, the photons lose energy, and the length of their path is reduced, the growth of the sphere slows down.

Time: 1.4×10 −7 s. Distance: 16 m. Temperature: 4 million °C.
In general, from 10−7 to 0.08 seconds, the first phase of the glow of the sphere goes on with a rapid drop in temperature and an output of ~ 1% of the radiation energy, mostly in the form of UV rays and the brightest light radiation that can damage the vision of a distant observer without skin burns . The illumination of the earth's surface at these moments at distances up to tens of kilometers can be a hundred or more times greater than the sun.

Time: 1.7×10 −7 s. Distance: 21 m. Temperature: 3 million °C.
Bomb vapors in the form of clubs, dense clots and plasma jets, like a piston, compress the air in front of them and form a shock wave inside the sphere - an internal shock that differs from a conventional shock wave in non-adiabatic, almost isothermal properties, and at the same pressures several times higher density : the air compressing abruptly immediately radiates most of the energy through the ball, which is still transparent to radiation.
At the first tens of meters, the surrounding objects before the fire sphere hits them, due to its too high speed, do not have time to react in any way - they even practically do not heat up, and, once inside the sphere under the radiation flux, they evaporate instantly.

Time: 0.000001 s. Distance: 34 m. Temperature: 2 million °C. Speed ​​1000 km/s.
With the growth of the sphere and the drop in temperature, the energy and density of the photon flux decrease, and their path (about a meter) is no longer enough for near-light speeds of the expansion of the fire front. The heated volume of air began to expand, and a stream of its particles is formed from the center of the explosion. A thermal wave at still air at the boundary of the sphere slows down. The expanding heated air inside the sphere collides with the stationary one near its border, and, starting somewhere from 36-37 m, a wave of density increase appears - the future external air shock wave; before that, the wave did not have time to appear due to the huge growth rate of the light sphere.

Time: 0.000001 s. Distance: 34 m. Temperature: 2 million °C.
The internal shock and vapors of the bomb are located in a layer of 8-12 m from the explosion site, the pressure peak is up to 17000 MPa at a distance of 10.5 m, the density is ~4 times greater than the air density, the velocity is ~100 km/s. Hot air area: pressure at the boundary 2500 MPa, inside the area up to 5000 MPa, particle velocity up to 16 km/s. The bomb vapor matter begins to lag behind the internal surge as more and more of the air in it is drawn into motion. Dense clots and jets maintain speed.

Time: 0.000034 s. Distance: 42 m. Temperature: 1 million °C.
Conditions at the epicenter of the explosion of the first Soviet hydrogen bomb (400 kt at a height of 30 m), which formed a crater about 50 m in diameter and 8 m deep. At 15 m from the epicenter, or 5-6 m from the base of the tower with a charge, there was a reinforced concrete bunker with walls 2 m thick for placing scientific equipment on top, covered with a large mound of earth 8 m thick - destroyed.

Time: 0.0036 s. Distance: 60 m. Temperature: 600 thousand °C.
From this moment, the nature of the shock wave ceases to depend on the initial conditions of a nuclear explosion and approaches the typical one for a strong explosion in air, i.e. such wave parameters could be observed in the explosion of a large mass of conventional explosives.
The internal shock, having passed the entire isothermal sphere, catches up and merges with the external one, increasing its density and forming the so-called. a strong jump is a single front of the shock wave. The density of matter in the sphere drops to 1/3 atmospheric.

Time: 0.014 s. Distance: 110 m. Temperature: 400 thousand ° C.
A similar shock wave at the epicenter of the explosion of the first Soviet atomic bomb with a power of 22 kt at a height of 30 m generated a seismic shift that destroyed the imitation of metro tunnels with various types of support at depths of 10, 20 and 30 m; animals in tunnels at depths of 10, 20 and 30 m died. An inconspicuous dish-shaped depression about 100 m in diameter appeared on the surface. Similar conditions were at the epicenter of the Trinity explosion (21 kt at a height of 30 m, a funnel 80 m in diameter and 2 m deep formed).

Time: 0.004 s. Distance: 135 m. Temperature: 300 thousand °C.
The maximum height of an air burst is 1 Mt for the formation of a noticeable funnel in the ground. The front of the shock wave is curved by the blows of the bomb vapor clots.

Time: 0.007 s. Distance: 190 m. Temperature: 200 thousand °C.
Large “blisters” and bright spots form on the smooth and, as it were, shiny front of the shock wave (the sphere seems to be boiling). The density of matter in an isothermal sphere with a diameter of ~150 m falls below 10% of the atmospheric one.
Non-massive objects evaporate a few meters before the arrival of the fiery sphere (“rope tricks”); the human body from the side of the explosion will have time to char, and completely evaporate already with the arrival of the shock wave.

Time: 0.01 s. Distance: 214 m. Temperature: 200 thousand ° C.
A similar air shock wave of the first Soviet atomic bomb at a distance of 60 m (52 ​​m from the epicenter) destroyed the tips of the trunks leading to the simulated metro tunnels under the epicenter (see above). Each head was a powerful reinforced concrete casemate, covered with a small earth embankment. Fragments of the heads fell into the trunks, the latter were then crushed by a seismic wave.

Time: 0.015 s. Distance: 250 m. Temperature: 170 thousand °C.
The shock wave strongly destroys rocks. The shock wave speed is higher than the speed of sound in metal: the theoretical tensile strength of the entrance door to the shelter; the tank collapses and burns out.

Time: 0.028 s. Distance: 320 m. Temperature: 110 thousand °C.
A person is scattered by a stream of plasma (the speed of the shock wave is equal to the speed of sound in the bones, the body collapses into dust and immediately burns out). Complete destruction of the most durable ground structures.

Time: 0.073 s. Distance: 400 m. Temperature: 80 thousand °C.
Irregularities on the sphere disappear. The density of matter drops in the center to almost 1%, and at the edge of an isothermal sphere with a diameter of ~320 m - to 2% of the atmospheric density. At this distance, within 1.5 s, heating to 30000°C and falling to 7000°C, ~5 s holding at ~6500°C and decreasing temperature in 10-20 s as the fireball moves up.

Time: 0.079 s. Distance: 435 m. Temperature: 110 thousand ° C.
Complete destruction of highways with asphalt and concrete pavement. Temperature minimum of shock wave radiation, the end of the first glow phase. A subway-type shelter lined with cast-iron tubings with monolithic reinforced concrete and buried 18 m, according to the calculation, is able to withstand without destruction an explosion (40 kt) at a height of 30 m at a minimum distance of 150 m (shock wave pressure of the order of 5 MPa), tested 38 kt RDS -2 at a distance of 235 m (pressure ~ 1.5 MPa), received minor deformations, damage.
At temperatures in the compression front below 80 thousand ° C, new NO 2 molecules no longer appear, the nitrogen dioxide layer gradually disappears and ceases to screen the internal radiation. The shock sphere gradually becomes transparent, and through it, as through darkened glass, for some time, clubs of bomb vapors and an isothermal sphere are visible; in general, the fiery sphere is similar to fireworks. Then, as the transparency increases, the intensity of the radiation increases, and the details of the flaring up sphere, as it were, become invisible.

Time: 0.1 s. Distance: 530 m. Temperature: 70 thousand °C.
Separation and moving forward of the front of the shock wave from the boundary of the fiery sphere, its growth rate noticeably decreases. The second glow phase begins, less intense, but two orders of magnitude longer, with the release of 99% of the explosion radiation energy, mainly in the visible and IR spectrum. At the first hundreds of meters, a person does not have time to see the explosion and dies without suffering (a person's visual reaction time is 0.1-0.3 s, the reaction time to a burn is 0.15-0.2 s).

Time: 0.15 s. Distance: 580 m. Temperature: 65 thousand ° C. Radiation: ~100000 Gy.
Charred fragments of bones remain from a person (the speed of the shock wave is of the order of the speed of sound in soft tissues: a hydrodynamic shock that destroys cells and tissues passes through the body).

Time: 0.25 s. Distance: 630 m. Temperature: 50 thousand °C. Penetrating radiation: ~40000 Gy.
A person turns into charred debris: a shock wave causes traumatic amputations, and a fiery sphere that approaches in a split second chars the remains.
Complete destruction of the tank. Complete destruction of underground cable lines, water pipes, gas pipelines, sewers, manholes. Destruction of underground reinforced concrete pipes with a diameter of 1.5 m and a wall thickness of 0.2 m. Destruction of the arched concrete dam of a hydroelectric power station. Strong destruction of long-term reinforced concrete fortifications. Minor damage to underground metro structures.

Time: 0.4 s. Distance: 800 m. Temperature: 40 thousand °C.
Heating objects up to 3000°C. Penetrating radiation ~20000 Gy. Complete destruction of all protective structures of civil defense (shelters), destruction of the protective devices of the entrances to the subway. Destruction of the gravitational concrete dam of the HPP. Pillboxes become incapacitated at a distance of 250 m.

Time: 0.73 s. Distance: 1200 m. Temperature: 17 thousand ° C. Radiation: ~5000 Gy.
At an explosion height of 1200 m, heating of the surface air at the epicenter before the arrival of the shock wave to 900°C. Man - one hundred percent death from the action of the shock wave.
Destruction of shelters designed for 200 kPa (type A-III, or class 3). Complete destruction of reinforced concrete bunkers of prefabricated type at a distance of 500 m under the conditions of a ground explosion. Complete destruction of railroad tracks. The maximum brightness of the second phase of the glow of the sphere, by this time it has released ~ 20% of the light energy.

Time: 1.4 s. Distance: 1600 m. Temperature: 12 thousand ° C.
Heating objects up to 200°C. Radiation - 500 Gr. Numerous burns of 3-4 degrees up to 60-90% of the body surface, severe radiation injury, combined with other injuries; lethality immediately or up to 100% on the first day.
The tank is thrown back ~10 m and damaged. Complete destruction of metal and reinforced concrete bridges with a span of 30-50 m.

Time: 1.6 s. Distance: 1750 m. Temperature: 10 thousand °C. Radiation: approx. 70 Gr.
The crew of the tank dies within 2-3 weeks from extremely severe radiation sickness.
Complete destruction of concrete, reinforced concrete monolithic (low-rise) and earthquake-resistant buildings 0.2 MPa, built-in and free-standing shelters, designed for 100 kPa (type A-IV, or class 4), shelters in the basements of multi-storey buildings.

Time: 1.9 s. Distance: 1900 m. Temperature: 9 thousand ° C.
Dangerous damage to a person by a shock wave and rejection up to 300 m with an initial speed of up to 400 km / h; of which 100-150 m (0.3-0.5 of the path) is free flight, and the rest of the distance is numerous ricochets on the ground. Radiation of about 50 Gy is a lightning-fast form of radiation sickness, 100% lethality within 6-9 days.
Destruction of built-in shelters designed for 50 kPa. Strong destruction of earthquake-resistant buildings. Pressure 0.12 MPa and above - all dense and rarefied urban development turns into solid blockages (individual blockages merge into one continuous blockage), the height of the blockages can be 3-4 m. The fire sphere at this time reaches its maximum size (~ 2 km in diameter) , is crushed from below by the shock wave reflected from the ground and begins to rise; the isothermal sphere in it collapses, forming a fast upward flow in the epicenter - the future leg of the fungus.

Time: 2.6 s. Distance: 2200 m. Temperature: 7.5 thousand ° C.
Severe injury to a person by a shock wave. Radiation ~ 10 Gy - extremely severe acute radiation sickness, according to a combination of injuries, 100% mortality within 1-2 weeks. Safe stay in a tank, in a fortified basement with reinforced concrete floors and in most civil defense shelters.
Destruction of trucks. 0.1 MPa - design pressure of the shock wave for designing structures and protective devices of underground structures of shallow subway lines.

Time: 3.8 s. Distance: 2800 m. Temperature: 7.5 thousand ° C.
Radiation 1 Gy - in peaceful conditions and timely treatment, harmless radiation injury, but with the unsanitary conditions and severe physical and psychological stress, lack of medical care, nutrition and normal rest, up to half of the victims die only from radiation and concomitant diseases, and by the amount of damage ( plus injuries and burns) - much more.
Pressure less than 0.1 MPa - urban areas with dense buildings turn into solid blockages. Complete destruction of basements without reinforcement of structures 0.075 MPa. The average destruction of earthquake-resistant buildings is 0.08-0.12 MPa. Severe damage to prefabricated reinforced concrete pillboxes. Detonation of pyrotechnics.

Time: 6 s. Distance: 3600 m. Temperature: 4.5 thousand ° C.
Average damage to a person by a shock wave. Radiation ~ 0.05 Gy - the dose is not dangerous. People and objects leave "shadows" on the pavement.
Complete destruction of administrative multi-storey frame (office) buildings (0.05-0.06 MPa), shelters of the simplest type; strong and complete destruction of massive industrial structures. Almost all urban development has been destroyed with the formation of local blockages (one house - one blockage). Complete destruction of cars, complete destruction of the forest. An electromagnetic pulse of ~3 kV/m strikes insensitive electrical appliances. The destruction is similar to a magnitude 10 earthquake.
The sphere turned into a fiery dome, like a bubble floating up, dragging a column of smoke and dust from the surface of the earth: a characteristic explosive mushroom grows with an initial vertical speed of up to 500 km / h. The wind speed near the surface to the epicenter is ~100 km/h.

Time: 10 s. Distance: 6400 m. Temperature: 2 thousand °C.
The end of the effective time of the second glow phase, ~80% of the total energy of light radiation was released. The remaining 20% ​​are safely illuminated for about a minute with a continuous decrease in intensity, gradually getting lost in the puffs of the cloud. Destruction of shelters of the simplest type (0.035-0.05 MPa).
In the first kilometers, a person will not hear the roar of the explosion due to the damage to the hearing by the shock wave. Rejection of a person by a shock wave at ~20 m with an initial speed of ~30 km/h.
Complete destruction of multi-storey brick houses, panel houses, severe destruction of warehouses, moderate destruction of frame administrative buildings. The destruction is similar to an earthquake of magnitude 8. Safe in almost any basement.
The glow of the fiery dome ceases to be dangerous, it turns into a fiery cloud, growing in volume as it rises; incandescent gases in the cloud begin to rotate in a torus-shaped vortex; hot explosion products are localized in the upper part of the cloud. The flow of dusty air in the column moves twice as fast as the speed of the rise of the mushroom, overtakes the cloud, passes through, diverges and, as it were, winds up on it, like on a ring-shaped coil.

Time: 15 s. Distance: 7500 m.
Light damage to a person by a shock wave. Third-degree burns on exposed parts of the body.
Complete destruction of wooden houses, strong destruction of brick multi-storey buildings 0.02-0.03 MPa, average destruction of brick warehouses, multi-storey reinforced concrete, panel houses; weak destruction of administrative buildings 0.02-0.03 MPa, massive industrial buildings. Car fires. Destruction is similar to a 6-magnitude earthquake, a 12-magnitude hurricane with wind speeds up to 39 m/s. The mushroom has grown up to 3 km above the epicenter of the explosion (the true height of the mushroom is greater than the height of the warhead explosion, by about 1.5 km), it has a “skirt” of water vapor condensate in a stream of warm air, which is drawn like a fan by a cloud into the cold upper atmosphere.

Time: 35 s. Distance: 14 km.
Second degree burns. Paper ignites, dark tarpaulin. Zone of continuous fires; in areas of dense combustible buildings, a fire storm, a tornado are possible (Hiroshima, "Operation Gomorrah"). Weak destruction of panel buildings. Decommissioning aircraft and missiles. The destruction is similar to an earthquake with a magnitude of 4-5, a storm of 9-11 magnitudes with a wind speed of 21-28.5 m/s. The mushroom has grown up to ~5 km, the fiery cloud shines ever weaker.

Time: 1 min. Distance: 22 km.
First-degree burns, in beachwear, death is possible.
Destruction of reinforced glazing. Uprooting large trees. Zone of individual fires. The mushroom has risen to 7.5 km, the cloud ceases to emit light and now has a reddish tint due to the nitrogen oxides contained in it, which will stand out sharply from other clouds.

Time: 1.5 min. Distance: 35 km.
The maximum radius of destruction of unprotected sensitive electrical equipment by an electromagnetic pulse. Almost all ordinary and part of the reinforced glass in the windows were broken - actually in a frosty winter, plus the possibility of cuts by flying fragments.
The mushroom rose up to 10 km, the ascent speed was ~220 km/h. Above the tropopause, the cloud develops predominantly in width.

Time: 4 min. Distance: 85 km.
The flash is similar to a large and unnaturally bright Sun near the horizon, it can cause retinal burns, a surge of heat to the face. The shock wave that arrived after 4 minutes can still knock a person down and break individual panes in the windows.
The mushroom rose over 16 km, the ascent speed was ~140 km/h.

Time: 8 min. Distance: 145 km.
The flash is not visible beyond the horizon, but a strong glow and a fiery cloud are visible. The total height of the fungus is up to 24 km, the cloud is 9 km high and 20-30 km in diameter, with its wide part it “leans” on the tropopause. The mushroom cloud has grown to its maximum size and is observed for another hour or more, until it is blown away by the winds and mixed with the usual cloudiness. Precipitation with relatively large particles falls out of the cloud within 10-20 hours, forming a near radioactive trace.

Time: 5.5-13 hours. Distance: 300-500 km.
The far boundary of the zone of moderate infection (zone A). The level of radiation at the outer boundary of the zone is 0.08 Gy/h; total radiation dose 0.4-4 Gy.

Time: ~10 months.
Effective half-deposition time of radioactive substances for the lower layers of the tropical stratosphere (up to 21 km); fallout also takes place mainly in middle latitudes in the same hemisphere where the explosion was made.
===============

On October 30, 1961, the USSR exploded the most powerful bomb in world history: a 58-megaton hydrogen bomb ("Tsar Bomba") was detonated at a test site on the island of Novaya Zemlya. Nikita Khrushchev joked that the 100-megaton bomb was originally supposed to be detonated, but the charge was reduced so as not to break all the windows in Moscow.

Explosion AN602 according to the classification was a low air explosion of extra high power. His results were impressive:

• The fireball of the explosion reached a radius of approximately 4.6 kilometers. Theoretically, it could grow to the surface of the earth, but this was prevented by a reflected shock wave that crushed and threw the ball off the ground.
• The light radiation could potentially cause third-degree burns at distances up to 100 kilometers.
• Atmospheric ionization caused radio interference even hundreds of kilometers from the test site for about 40 minutes
• The tangible seismic wave resulting from the explosion circled the globe three times.
• Witnesses felt the impact and were able to describe the explosion at a distance of a thousand kilometers from its center.
• Nuclear mushroom explosion rose to a height of 67 kilometers; the diameter of its two-tier "hat" reached (near the upper tier) 95 kilometers.
• The sound wave generated by the explosion reached Dixon Island at a distance of about 800 kilometers. However, sources do not report any destruction or damage to structures, even in those located much closer (280 km) to the landfill, the urban-type settlement of Amderma and the settlement of Belushya Guba.
• The radioactive contamination of the experimental field with a radius of 2-3 km in the area of ​​the epicenter was no more than 1 mR/hour, the testers appeared at the site of the epicenter 2 hours after the explosion. Radioactive contamination posed little to no danger to test participants

All nuclear explosions produced by the countries of the world in one video:

The creator of the atomic bomb, Robert Oppenheimer, said on the day of the first test of his brainchild: “If hundreds of thousands of suns rose at once in the sky, their light could be compared with the radiance emanating from the Supreme Lord ... I am Death, the great destroyer of worlds, bringing death to all living things ". These words were a quotation from the Bhagavad Gita, which the American physicist read in the original.

Photographers from Lookout Mountain stand waist-deep in dust raised by the shock wave after a nuclear explosion (photo from 1953).

Challenge Name: Umbrella
Date: June 8, 1958

Power: 8 kilotons

An underwater nuclear explosion was carried out during Operation Hardtack. Decommissioned ships were used as targets.

Test name: Chama (as part of the Dominic project)
Date: October 18, 1962
Location: Johnston Island
Capacity: 1.59 megatons

Test Name: Oak
Date: June 28, 1958
Location: Eniwetok Lagoon in the Pacific Ocean
Capacity: 8.9 megatons

Upshot-Knothole project, Annie test. Date: March 17, 1953; project: Upshot-Knothole; test: Annie; Location: Knothole, Nevada Proving Ground, Sector 4; power: 16 kt. (Photo: Wikicommons)

Challenge Name: Castle Bravo
Date: March 1, 1954
Location: Bikini Atoll
Explosion type: on the surface
Capacity: 15 megatons

The explosion of the Castle Bravo hydrogen bomb was the most powerful explosion ever carried out by the United States. The power of the explosion turned out to be much higher than the initial forecasts of 4-6 megatons.

Challenge Name: Castle Romeo
Date: March 26, 1954
Location: On a barge in Bravo Crater, Bikini Atoll
Explosion type: on the surface
Capacity: 11 megatons

The power of the explosion turned out to be 3 times greater than the initial forecasts. Romeo was the first test made on a barge.

Project Dominic, Test Aztec

Trial Name: Priscilla (as part of the Plumbbob trial series)
Date: 1957

Power: 37 kilotons

This is exactly what the process of releasing a huge amount of radiant and thermal energy during an atomic explosion in the air over the desert looks like. Here you can still see military equipment, which in a moment will be destroyed by a shock wave, imprinted in the form of a crown that surrounded the epicenter of the explosion. You can see how the shock wave was reflected from the earth's surface and is about to merge with the fireball.

Test name: Grable (as part of Operation Upshot Knothole)
Date: 25 May 1953
Location: Nevada Nuclear Test Site
Power: 15 kilotons

At a test site in the Nevada desert, photographers from the Lookout Mountain Center in 1953 took a photograph of an unusual phenomenon (a ring of fire in a nuclear mushroom after an explosion of a projectile from a nuclear cannon), the nature of which has long occupied the minds of scientists.

Upshot-Knothole project, Rake test. As part of this test, a 15 kiloton atomic bomb was detonated, launched by a 280 mm atomic cannon. The test took place on May 25, 1953 at the Nevada test site. (Photo: National Nuclear Security Administration / Nevada Site Office)

A mushroom cloud formed by the atomic explosion of the Truckee test carried out as part of Project Dominic.

Project Buster, Test Dog.

Project "Dominic", test "Yeso". Trial: Yeso; date: June 10, 1962; project: Dominic; location: 32 km south of Christmas Island; test type: B-52, atmospheric, height - 2.5 m; power: 3.0 mt; charge type: atomic. (Wikicommons)

Test Name: YESO
Date: June 10, 1962
Location: Christmas Island
Power: 3 megatons

Test "Licorn" in French Polynesia. Image #1. (Pierre J./French Army)

Test name: "Unicorn" (fr. Licorne)
Date: July 3, 1970
Location: atoll in French Polynesia
Power: 914 kilotons

Test "Licorn" in French Polynesia. Image #2. (Photo: Pierre J./French Army)

Test "Licorn" in French Polynesia. Image #3. (Photo: Pierre J./French Army)

Test sites often have entire teams of photographers working to get good shots. In the photo: a nuclear test explosion in the Nevada desert. To the right are the missile plumes that scientists use to determine the characteristics of the shock wave.

Test "Licorn" in French Polynesia. Image #4. (Photo: Pierre J./French Army)

Project Castle, test Romeo. (Photo: zvis.com)

Hardtack project, Umbrella test. Challenge: Umbrella; date: June 8, 1958; project: Hardtack I; Location: Eniwetok Atoll Lagoon test type: underwater, depth 45 m; power: 8kt; charge type: atomic.

Project Redwing, Seminole test. (Photo: Nuclear Weapons Archive)

Riya test. Atmospheric test of an atomic bomb in French Polynesia in August 1971. As part of this test, which took place on August 14, 1971, a thermonuclear warhead, codenamed "Riya", with a capacity of 1000 kt, was detonated. The explosion occurred on the territory of the Mururoa atoll. This picture was taken from a distance of 60 km from zero. Photo: Pierre J.

Mushroom cloud from a nuclear explosion over Hiroshima (left) and Nagasaki (right). In the final stages of World War II, the United States launched two atomic strikes on Hiroshima and Nagasaki. The first explosion occurred on August 6, 1945, and the second on August 9, 1945. This was the only time that nuclear weapons were used for military purposes. By order of President Truman, on August 6, 1945, the US Army dropped the "Baby" nuclear bomb on Hiroshima, followed by the nuclear explosion of the "Fat Man" bomb on Nagasaki on August 9. Between 90,000 and 166,000 people died in Hiroshima within 2-4 months after the nuclear explosions, and between 60,000 and 80,000 died in Nagasaki. (Photo: Wikicommons)

Upshot-Knothole project. Landfill in Nevada, March 17, 1953. The blast wave completely destroyed Building No. 1, located at a distance of 1.05 km from the zero mark. The time difference between the first and second shot is 21/3 seconds. The camera was placed in a protective case with a wall thickness of 5 cm. The only source of light in this case was a nuclear flash. (Photo: National Nuclear Security Administration / Nevada Site Office)

Project Ranger, 1951. The name of the test is unknown. (Photo: National Nuclear Security Administration / Nevada Site Office)

Trinity test.

Trinity was the code name for the first nuclear test. This test was conducted by the United States Army on July 16, 1945, at an area approximately 56 kilometers southeast of Socorro, New Mexico, at the White Sands Missile Range. For the test, an implosion-type plutonium bomb was used, nicknamed "Thing". After the detonation, there was an explosion with a power equivalent to 20 kilotons of TNT. The date of this test is considered the beginning of the atomic era. (Photo: Wikicommons)

Challenge Name: Mike
Date: October 31, 1952
Location: Elugelab ("Flora") Island, Eneweita Atoll
Power: 10.4 megatons

The device detonated in Mike's test, dubbed the "sausage", was the first true megaton-class "hydrogen" bomb. The mushroom cloud reached a height of 41 km with a diameter of 96 km.

Explosion "MET", carried out as part of Operation "Teepot". It is noteworthy that the MET explosion was comparable in power to the Fat Man plutonium bomb dropped on Nagasaki. April 15, 1955, 22 ct. (Wiki media)

One of the most powerful explosions of a thermonuclear hydrogen bomb on the account of the United States is Operation Castle Bravo. The charge power was 10 megatons. The explosion took place on March 1, 1954 in Bikini Atoll, Marshall Islands. (Wiki media)

Operation Castle Romeo is one of the most powerful thermonuclear bomb explosions carried out by the United States. Bikini Atoll, March 27, 1954, 11 megatons. (Wiki media)

The Baker explosion, showing the white surface of the water disturbed by the air shock wave and the top of the hollow column of spray that formed the hemispherical Wilson cloud. In the background is the coast of Bikini Atoll, July 1946. (Wiki media)

The explosion of the American thermonuclear (hydrogen) bomb "Mike" with a capacity of 10.4 megatons. November 1, 1952 (Wiki media)

Operation Greenhouse is the fifth series of American nuclear tests and the second of them in 1951. During the operation, designs of nuclear charges were tested using thermonuclear fusion to increase the energy yield. In addition, the impact of the explosion on structures, including residential buildings, factory buildings and bunkers, was studied. The operation was carried out at the Pacific nuclear test site. All devices were blown up on high metal towers, simulating an air explosion. Explosion of "George", 225 kilotons, May 9, 1951. (Wiki media)

A mushroom cloud that has a column of water instead of a dust leg. On the right, a hole is visible on the pillar: the battleship Arkansas blocked the spray. Test "Baker", charge capacity - 23 kilotons of TNT, July 25, 1946. (Wiki media)

A 200-meter cloud over the territory of Frenchman Flat after the MET explosion as part of Operation Tipot, April 15, 1955, 22 kt. This projectile had a rare uranium-233 core. (Wiki media)

The crater was formed when a 100 kiloton blast wave was blasted under 635 feet of desert on July 6, 1962, displacing 12 million tons of earth.

Time: 0s. Distance: 0m. Initiation of the explosion of a nuclear detonator.
Time: 0.0000001c. Distance: 0m Temperature: up to 100 million °C. The beginning and course of nuclear and thermonuclear reactions in a charge. With its explosion, a nuclear detonator creates the conditions for the start of thermonuclear reactions: the thermonuclear combustion zone passes by a shock wave in the charge substance at a speed of about 5000 km / s (106 - 107 m / s) About 90% of the neutrons released during the reactions are absorbed by the bomb substance, the remaining 10% fly out out.

Time: 10-7c. Distance: 0m. Up to 80% or more of the energy of the reacting substance is transformed and released in the form of soft X-ray and hard UV radiation with enormous energy. The X-rays form a heat wave that heats up the bomb, escapes and begins to heat the surrounding air.

Time:< 10−7c. Расстояние: 2м Temperature: 30 million°C. The end of the reaction, the beginning of the expansion of the bomb substance. The bomb immediately disappears from sight and a bright luminous sphere (fireball) appears in its place, masking the spread of the charge. The growth rate of the sphere in the first meters is close to the speed of light. The density of the substance here drops to 1% of the density of the surrounding air in 0.01 seconds; the temperature drops to 7-8 thousand °C in 2.6 seconds, it is held for ~5 seconds and further decreases with the rise of the fiery sphere; pressure after 2-3 seconds drops to slightly below atmospheric.

Time: 1.1x10−7c. Distance: 10m Temperature: 6 million °C. The expansion of the visible sphere up to ~10 m is due to the glow of ionized air under the X-ray radiation of nuclear reactions, and then through the radiative diffusion of the heated air itself. The energy of radiation quanta leaving the thermonuclear charge is such that their free path before being captured by air particles is on the order of 10 m and is initially comparable to the size of a sphere; photons quickly run around the entire sphere, averaging its temperature and fly out of it at the speed of light, ionizing more and more layers of air, hence the same temperature and near-light growth rate. Further, from capture to capture, photons lose energy and their path length is reduced, the growth of the sphere slows down.

Time: 1.4x10−7c. Distance: 16m Temperature: 4 million °C. In general, from 10−7 to 0.08 seconds, the 1st phase of the glow of the sphere goes on with a rapid drop in temperature and an output of ~ 1% of the radiation energy, mostly in the form of UV rays and the brightest light radiation that can damage the vision of a distant observer without formation skin burns. The illumination of the earth's surface at these moments at distances up to tens of kilometers can be a hundred or more times greater than the sun.

Time: 1.7x10-7c. Distance: 21m Temperature: 3 million °C. Bomb vapors in the form of clubs, dense clots and jets of plasma, like a piston, compress air in front of them and form a shock wave inside the sphere - an internal shock that differs from a conventional shock wave in non-adiabatic, almost isothermal properties and at the same pressures several times higher density: compressing with a shock the air immediately radiates most of the energy through the ball, which is still transparent to radiation.
At the first tens of meters, the surrounding objects before the fire sphere hits them, due to its too high speed, do not have time to react in any way - they even practically do not heat up, and once inside the sphere under the radiation flux they evaporate instantly.

Temperature: 2 million °C. Speed ​​1000 km/s. As the sphere grows and the temperature drops, the energy and density of the photon flux decrease, and their range (of the order of a meter) is no longer enough for near-light velocities of the fire front expansion. The heated volume of air began to expand and a stream of its particles is formed from the center of the explosion. A thermal wave at still air at the boundary of the sphere slows down. The expanding heated air inside the sphere collides with the stationary air near its boundary, and somewhere from 36-37 m a density increase wave appears - a future external air shock wave; before that, the wave did not have time to appear due to the huge growth rate of the light sphere.

Time: 0.000001s. Distance: 34m Temperature: 2 million °C. The internal surge and bomb vapors are located in a layer of 8-12 m from the explosion site, the pressure peak is up to 17,000 MPa at a distance of 10.5 m, the density is ~ 4 times the air density, the speed is ~ 100 km/s. Hot air area: pressure at the boundary 2.500 MPa, inside the area up to 5000 MPa, particle velocity up to 16 km/s. The bomb vapor substance begins to lag behind the internal. jump as more and more air in it is involved in movement. Dense clots and jets maintain speed.

Time: 0.000034c. Distance: 42m Temperature: 1 million °C. Conditions at the epicenter of the explosion of the first Soviet hydrogen bomb (400 kt at a height of 30 m), which formed a crater about 50 m in diameter and 8 m deep. At 15 m from the epicenter or 5-6 m from the base of the tower with the charge, there was a reinforced concrete bunker with walls 2 m thick. For placing scientific equipment on top, covered with a large mound of earth 8 m thick, was destroyed.

Temperature: 600 thousand ° C. From this moment, the nature of the shock wave ceases to depend on the initial conditions of a nuclear explosion and approaches the typical one for a strong explosion in air, i.e. such wave parameters could be observed in the explosion of a large mass of conventional explosives.

Time: 0.0036s. Distance: 60m Temperature: 600 thousand ° C. The internal shock, having passed the entire isothermal sphere, catches up and merges with the external one, increasing its density and forming the so-called. a strong jump is a single front of the shock wave. The density of matter in the sphere drops to 1/3 atmospheric.

Time: 0.014c. Distance: 110m Temperature: 400 thousand ° C. A similar shock wave at the epicenter of the explosion of the first Soviet atomic bomb with a power of 22 kt at a height of 30 m generated a seismic shift that destroyed an imitation of metro tunnels with various types of fastenings at depths of 10 and 20 m 30 m, animals in tunnels at depths of 10, 20 and 30 m died . An inconspicuous dish-shaped depression about 100 m in diameter appeared on the surface. Similar conditions were at the epicenter of the Trinity explosion of 21 kt at a height of 30 m, a funnel 80 m in diameter and 2 m deep was formed.

Time: 0.004s. Distance: 135m
Temperature: 300 thousand ° C. The maximum height of an air burst is 1 Mt for the formation of a noticeable funnel in the ground. The front of the shock wave is curved by the impacts of the bomb vapor clots:

Time: 0.007s. Distance: 190m Temperature: 200k°C. On a smooth and, as it were, shiny front, oud. waves form large blisters and bright spots (the sphere seems to be boiling). The density of matter in an isothermal sphere with a diameter of ~150 m falls below 10% of atmospheric density.
Non-massive objects evaporate a few meters before the fire arrives. spheres ("Rope tricks"); the human body from the side of the explosion will have time to char, and completely evaporate already with the arrival of the shock wave.

Time: 0.01s. Distance: 214m Temperature: 200k°C. A similar air shock wave of the first Soviet atomic bomb at a distance of 60 m (52 ​​m from the epicenter) destroyed the tips of the trunks leading to the simulated metro tunnels under the epicenter (see above). Each head was a powerful reinforced concrete casemate, covered with a small earth embankment. Fragments of the heads fell into the trunks, the latter were then crushed by a seismic wave.

Time: 0.015s. Distance: 250m Temperature: 170 thousand ° C. The shock wave strongly destroys rocks. The shock wave speed is higher than the speed of sound in metal: the theoretical tensile strength of the entrance door to the shelter; the tank collapses and burns out.

Time: 0.028c. Distance: 320m Temperature: 110 thousand ° C. A person is dispersed by a stream of plasma (shock wave speed = speed of sound in the bones, the body collapses into dust and immediately burns out). Complete destruction of the most durable ground structures.

Time: 0.073c. Distance: 400m Temperature: 80 thousand ° C. Irregularities on the sphere disappear. The density of the substance drops in the center to almost 1%, and at the edge of the isotherms. spheres with a diameter of ~320 m to 2% atmospheric. At this distance, within 1.5 s, heating to 30,000 °C and falling to 7000 °C, ~5 s holding at ~6.500 °C and decreasing temperature in 10-20 s as the fireball goes up.

Time: 0.079c. Distance: 435m Temperature: 110 thousand ° C. Complete destruction of highways with asphalt and concrete pavement. Temperature minimum of shock wave radiation, the end of the 1st glow phase. A subway-type shelter, lined with cast-iron tubing and monolithic reinforced concrete and buried 18 m, is calculated to be able to withstand an explosion (40 kt) at a height of 30 m at a minimum distance of 150 m (shock wave pressure of the order of 5 MPa) without destruction, 38 kt RDS- 2 at a distance of 235 m (pressure ~1.5 MPa), received minor deformations and damage. At temperatures in the compression front below 80,000°C, new NO2 molecules no longer appear, the nitrogen dioxide layer gradually disappears and ceases to screen the internal radiation. The shock sphere gradually becomes transparent and through it, as through darkened glass, for some time, clubs of bomb vapors and an isothermal sphere are visible; in general, the fiery sphere is similar to fireworks. Then, as the transparency increases, the intensity of the radiation increases and the details of the flaring up sphere, as it were, become invisible. The process resembles the end of the era of recombination and the birth of light in the Universe several hundred thousand years after the Big Bang.

Time: 0.1s. Distance: 530m Temperature: 70 thousand ° C. Separation and moving forward of the front of the shock wave from the boundary of the fiery sphere, its growth rate noticeably decreases. The 2nd phase of the glow begins, less intense, but two orders of magnitude longer, with the release of 99% of the explosion radiation energy mainly in the visible and IR spectrum. At the first hundreds of meters, a person does not have time to see the explosion and dies without suffering (a person's visual reaction time is 0.1 - 0.3 s, the reaction time to a burn is 0.15 - 0.2 s).

Time: 0.15s. Distance: 580m Temperature: 65k°C. Radiation ~100 000 Gy. Charred fragments of bones remain from a person (the speed of the shock wave is of the order of the speed of sound in soft tissues: a hydrodynamic shock that destroys cells and tissues passes through the body).

Time: 0.25s. Distance: 630m Temperature: 50 thousand ° C. Penetrating radiation ~40 000 Gy. A person turns into charred debris: a shock wave causes traumatic amputationsa coming up in a fraction of a second. a fiery sphere chars the remains. Complete destruction of the tank. Complete destruction of underground cable lines, water pipes, gas pipelines, sewers, manholes. Destruction of underground reinforced concrete pipes with a diameter of 1.5 m, with a wall thickness of 0.2 m. Destruction of the arched concrete dam of the HPP. Strong destruction of long-term reinforced concrete fortifications. Minor damage to underground metro structures.

Time: 0.4s. Distance: 800m Temperature: 40 thousand ° C. Heating objects up to 3000 °C. Penetrating radiation ~20 000 Gy. Complete destruction of all protective structures of civil defense (shelters) destruction of the protective devices of entrances to the subway. Destruction of the gravitational concrete dam of the hydroelectric power station Pillboxes become incapable of combat at a distance of 250 m.

Time: 0.73c. Distance: 1200m Temperature: 17 thousand ° C. Radiation ~5000 Gy. At an explosion height of 1200 m, the heating of surface air at the epicenter before the arrival of beats. waves up to 900°C. Man - 100% death from the action of the shock wave. Destruction of shelters rated at 200 kPa (type A-III or class 3). Complete destruction of reinforced concrete bunkers of prefabricated type at a distance of 500 m under the conditions of a ground explosion. Complete destruction of railroad tracks. The maximum brightness of the second phase of the glow of the sphere by this time it released ~ 20% of the light energy

Time: 1.4c. Distance: 1600m Temperature: 12k°C. Heating objects up to 200°C. Radiation 500 Gr. Numerous burns of 3-4 degrees up to 60-90% of the body surface, severe radiation injury, combined with other injuries, lethality immediately or up to 100% on the first day. The tank is thrown back ~ 10 m and damaged. Complete destruction of metal and reinforced concrete bridges with a span of 30-50 m.

Time: 1.6s. Distance: 1750m Temperature: 10 thousand ° C. Radiation ok. 70 Gr. The crew of the tank dies within 2-3 weeks from extremely severe radiation sickness. Complete destruction of concrete, reinforced concrete monolithic (low-rise) and seismic-resistant buildings 0.2 MPa, built-in and free-standing shelters rated at 100 kPa (type A-IV or class 4), shelters in the basements of multi-storey buildings.

Time: 1.9c. Distance: 1900m Temperature: 9 thousand ° C Dangerous damage to a person by a shock wave and rejection up to 300 m with an initial speed of up to 400 km / h, of which 100-150 m (0.3-0.5 of the path) is free flight, and the rest of the distance is numerous ricochets about the ground. Radiation of about 50 Gy is a lightning-fast form of radiation sickness [, 100% lethality within 6-9 days. Destruction of built-in shelters designed for 50 kPa. Strong destruction of earthquake-resistant buildings. Pressure 0.12 MPa and above - all dense and rarefied urban buildings turn into solid blockages (individual blockages merge into one continuous blockage), the height of the blockages can be 3-4 m. The fiery sphere at this time reaches its maximum size (D ~ 2 km), is crushed from below by a shock wave reflected from the ground and begins to rise; the isothermal sphere in it collapses, forming a fast upward flow in the epicenter - the future leg of the fungus.

Time: 2.6c. Distance: 2200m Temperature: 7.5 thousand ° C. Severe injury to a person by a shock wave. Radiation ~ 10 Gy - extremely severe acute radiation sickness, according to a combination of injuries, 100% mortality within 1-2 weeks. Safe stay in a tank, in a fortified basement with a reinforced reinforced concrete floor and in most shelters G. O. Destruction of trucks. 0.1 MPa - design pressure of the shock wave for designing structures and protective devices of underground structures of shallow subway lines.

Time: 3.8c. Distance: 2800m Temperature: 7.5 thousand ° C. Radiation 1 Gy - in peaceful conditions and timely treatment, harmless radiation injury, but with the unsanitary conditions and severe physical and psychological stress, lack of medical care, nutrition and normal rest, up to half of the victims die only from radiation and concomitant diseases, and by the amount of damage ( plus injuries and burns) much more. Pressure less than 0.1 MPa - urban areas with dense buildings turn into solid blockages. Complete destruction of basements without reinforcement of structures 0.075 MPa. The average destruction of earthquake-resistant buildings is 0.08-0.12 MPa. Severe damage to prefabricated reinforced concrete pillboxes. Detonation of pyrotechnics.

Time: 6c. Distance: 3600m Temperature: 4.5 thousand ° C. Average damage to a person by a shock wave. Radiation ~ 0.05 Gy - the dose is not dangerous. People and objects leave "shadows" on the pavement. Complete destruction of administrative multi-storey frame (office) buildings (0.05-0.06 MPa), shelters of the simplest type; strong and complete destruction of massive industrial structures. Almost all urban development has been destroyed with the formation of local blockages (one house - one blockage). Complete destruction of cars, complete destruction of the forest. An electromagnetic pulse of ~3 kV/m strikes insensitive electrical appliances. Destruction is similar to an earthquake of 10 points. The sphere turned into a fiery dome, like a bubble floating up, dragging a column of smoke and dust from the surface of the earth: a characteristic explosive mushroom grows with an initial vertical speed of up to 500 km / h. The wind speed near the surface to the epicenter is ~100 km/h.

Time: 10c. Distance: 6400m Temperature: 2k°C. The end of the effective time of the second glow phase, ~80% of the total energy of light radiation was released. The remaining 20% ​​are safely illuminated for about a minute with a continuous decrease in intensity, gradually getting lost in the puffs of the cloud. Destruction of shelters of the simplest type (0.035-0.05 MPa). In the first kilometers, a person will not hear the roar of the explosion due to the damage to the hearing by the shock wave. Rejection of a person by a shock wave of ~20 m with an initial speed of ~30 km/h. Complete destruction of multi-storey brick houses, panel houses, severe destruction of warehouses, moderate destruction of frame administrative buildings. The destruction is similar to an earthquake of 8 points. Safe in almost any basement.
The glow of the fiery dome ceases to be dangerous, it turns into a fiery cloud, growing in volume as it rises; incandescent gases in the cloud begin to rotate in a torus-shaped vortex; hot explosion products are localized in the upper part of the cloud. The flow of dusty air in the column moves twice as fast as the “mushroom” rises, overtakes the cloud, passes through, diverges and, as it were, winds up on it, like on a ring-shaped coil.

Time: 15c. Distance: 7500m. Light damage to a person by a shock wave. Third-degree burns on exposed parts of the body. Complete destruction of wooden houses, strong destruction of brick multi-storey buildings 0.02-0.03 MPa, average destruction of brick warehouses, multi-storey reinforced concrete, panel houses; weak destruction of administrative buildings 0.02-0.03 MPa, massive industrial buildings. Car fires. Destruction is similar to a 6 magnitude earthquake, a 12 magnitude hurricane. up to 39 m/s. The "mushroom" has grown up to 3 km above the center of the explosion (the true height of the mushroom is more than the height of the warhead explosion, by about 1.5 km), it has a "skirt" of water vapor condensate in a stream of warm air, which is drawn like a fan by a cloud into the cold upper layers atmosphere.

Time: 35c. Distance: 14km. Second degree burns. Paper ignites, dark tarpaulin. A zone of continuous fires, in areas of dense combustible buildings, a fire storm, a tornado are possible (Hiroshima, "Operation Gomorrah"). Weak destruction of panel buildings. Decommissioning aircraft and missiles. The destruction is similar to an earthquake of 4-5 points, a storm of 9-11 points V = 21 - 28.5 m/s. "Mushroom" has grown to ~5 km fiery cloud shines ever weaker.

Time: 1min. Distance: 22km. First degree burns - death is possible in beach clothes. Destruction of reinforced glazing. Uprooting large trees. The zone of separate fires. The “mushroom” has risen to 7.5 km, the cloud stops emitting light and now has a reddish tint due to the nitrogen oxides it contains, which will stand out sharply from other clouds.

Time: 1.5min. Distance: 35km. The maximum radius of destruction of unprotected sensitive electrical equipment by an electromagnetic pulse. Almost all ordinary and part of the reinforced glass in the windows were broken - actually in a frosty winter, plus the possibility of cuts by flying fragments. "Mushroom" climbed up to 10 km, climbing speed ~ 220 km/h. Above the tropopause, the cloud develops predominantly in width.
Time: 4min. Distance: 85km. The flare is like a large unnaturally bright sun near the horizon, can cause retinal burns, a rush of heat to the face. The shock wave that arrived after 4 minutes can still knock a person down and break individual panes in the windows. "Mushroom" climbed over 16 km, climbing speed ~ 140 km / h

Time: 8min. Distance: 145km. The flash is not visible beyond the horizon, but a strong glow and a fiery cloud are visible. The total height of the "mushroom" is up to 24 km, the cloud is 9 km high and 20-30 km in diameter, with its wide part it "leans" on the tropopause. The mushroom cloud has grown to its maximum size and is observed for about an hour or more, until it is blown away by the winds and mixed with the usual cloudiness. Precipitation with relatively large particles falls out of the cloud within 10-20 hours, forming a near radioactive trace.

Time: 5.5-13 hours Distance: 300-500km. The far boundary of the zone of moderate infection (zone A). The level of radiation at the outer boundary of the zone is 0.08 Gy/h; total radiation dose 0.4-4 Gy.

Time: ~10 months. The effective half-time of radioactive substances settling for the lower layers of the tropical stratosphere (up to 21 km), the fallout also occurs mainly in the middle latitudes in the same hemisphere where the explosion was made.

Monument to the first test of the Trinity atomic bomb. This monument was erected at White Sands in 1965, 20 years after the Trinity test. The memorial plaque of the monument reads: "On this site, on July 16, 1945, the world's first test of the atomic bomb took place." Another plaque, installed below, indicates that this place has received the status of a national historical monument. (Photo: Wikicommons)