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, in defeated Germany, Potsdam Conference). 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 pressure of 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 of fragments of fission of a nuclear charge and part of the residual uranium-235 or plutonium-239 to the ground.
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, % | 43,5 | 27,0 | 19,0 | 14,5 | 11,6 | 7,15 | 5,05 | 0,96 |
||||||||||||||||||||
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 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 extremely effective tool to damage electronic equipment. The SDI program provides for the conduct of special explosions, which create EMI sufficient to destroy electronics.
All the creators of nuclear weapons sincerely believed that they were doing a good deed, saving the world from the "brown plague", "communist infection" and "imperialist expansion". For countries striving to possess the energy of the atom, this was an extremely important task - the bomb acted as a symbol and guarantor of their national security and a peaceful future. The most deadly of all the murder weapons invented by man in the eyes of the creators was also the most powerful guarantor of peace on Earth.
At the heart of division and synthesis
The decades that have passed since the sad events of early August 1945 - the explosions of American atomic bombs over the Japanese cities of Hiroshima and Nagasaki - have confirmed the correctness of scientists who have given politicians an unprecedented weapon of attack and retaliation. Two combat uses were enough to ensure that we could live 60 years without the use of nuclear weapons in military operations. And I really hope that this species weapons will remain the main deterrent to a new world war and will never be used for combat purposes.
Nuclear weapons are defined as "explosive weapons of mass destruction based on the use of energy released during nuclear fission or fusion reactions." Accordingly, nuclear charges are divided into nuclear and thermonuclear. Ways to release the energy of the atomic nucleus through fission or fusion were clear to physicists by the end of the 1930s. The first path assumed a chain reaction of nuclear fission of heavy elements, the second - the fusion of nuclei of light elements with the formation of a heavier nucleus. The power of a nuclear charge is usually expressed in terms of "TNT equivalent", that is, the amount of conventional TNT explosive that must be detonated to release the same energy. One nuclear bomb may be equivalent on such a scale to a million tons of TNT, but the consequences of its explosion can be much worse than the explosion of a billion tons of conventional explosives.
Consequences of enrichment
To obtain nuclear energy by fission, of particular interest are the nuclei of uranium isotopes with atomic weights 233 and 235 (233 U and 235 U) and plutonium - 239 (239 Pu), fissile under the influence of neutrons. The connection of particles in all nuclei is due to strong interaction, which is especially effective at small distances. In large nuclei of heavy elements, this bond is weaker, since the electrostatic forces of repulsion between protons, as it were, “loosen” the nucleus. The decay of a heavy element nucleus under the action of a neutron into two fast-flying fragments is accompanied by the release of a large amount of energy, the emission of gamma quanta and neutrons - an average of 2.46 neutrons per decayed uranium nucleus and 3.0 neutrons per one plutonium nucleus. Due to the fact that the number of neutrons increases sharply during the decay of nuclei, the fission reaction can instantly cover all the nuclear fuel. This happens when a “critical mass” is reached, when a fission chain reaction begins, leading to an atomic explosion.
1 - body
2 - explosive mechanism
3 - conventional explosive
4 - electric detonator
5 - neutron reflector
6 - nuclear fuel (235U)
7 - neutron source
8 - the process of compressing nuclear fuel with an inward-directed explosion
Depending on the method of obtaining the critical mass, atomic ammunition of the cannon and implosive types are distinguished. In a simple cannon-type ammunition, two masses of 235 U, each of which is less than critical, are connected using a charge of a conventional explosive (BB) by firing from a kind of internal gun. Nuclear fuel can be divided into more parts that will be connected by the explosion of explosives surrounding them. Such a scheme is more complicated, but allows you to achieve high charge powers.
In an implosion-type munition, uranium 235 U or plutonium 239 Pu is compressed by an explosion of a conventional explosive located around them. Under the action of a blast wave, the density of uranium or plutonium rises sharply and the "supercritical mass" is achieved with a smaller amount of fissile material. For a more efficient chain reaction, the fuel in both types of ammunition is surrounded by a neutron reflector, for example, based on beryllium, and a neutron source is placed in the center of the charge to initiate the reaction.
The isotope 235 U, necessary to create a nuclear charge, in natural uranium contains only 0.7%, the rest is the stable isotope 238 U. To obtain a sufficient amount of fissile material, natural uranium is enriched, and this was one of the most technically difficult tasks in creation atomic bomb. Plutonium is obtained artificially - it accumulates in industrial nuclear reactors, due to the conversion of 238 U into 239 Pu under the action of a neutron flux.
Mutual Intimidation Club
Explosion of the Soviet nuclear bomb On August 29, 1949, he informed everyone about the end of the American nuclear monopoly. But the nuclear race was just unfolding, and new participants soon joined it.
On October 3, 1952, with the explosion of its own charge, Great Britain announced its entry into the "nuclear club", on February 13, 1960 - France, and on October 16, 1964 - China.
The political impact of nuclear weapons as a means of mutual blackmail is well known. The threat of a rapid nuclear retaliatory strike on the enemy has been and remains the main deterrent, forcing the aggressor to look for other ways of conducting military operations. This was also manifested in the specific nature of the third world war, which was cautiously called "cold".
The official "nuclear strategy" well reflected the assessment of the overall military power. So, if the Soviet state, quite confident in its strength, in 1982 announced “not to be the first to use nuclear weapons,” then Yeltsin’s Russia was forced to announce the possibility of using nuclear weapons even against a “non-nuclear” adversary. The “Nuclear Missile Shield” has remained today the main guarantee against external danger and one of the main pillars of an independent policy. The United States in 2003, when the aggression against Iraq was already a settled matter, moved from chattering about "non-lethal" weapons to the threat of "the possible use of tactical nuclear weapons." Another example. Already in the first years of the 21st century, India and Pakistan joined the "nuclear club". And almost immediately followed by a sharp escalation of confrontation on their border.
IAEA experts and the press have long argued that Israel is "able" to produce several dozen nuclear weapons. The Israelis, on the other hand, prefer to smile mysteriously - the very possibility of having nuclear weapons remains a powerful means of pressure even in regional conflicts.
According to the implosive scheme
With a sufficient approach of the nuclei of light elements, nuclear forces of attraction begin to act between them, which makes it possible to synthesize nuclei of heavier elements, which, as is known, is more productive than decay. Complete fusion in 1 kg of a mixture that is optimal for a thermonuclear reaction gives 3.7-4.2 times more energy than the complete decay of 1 kg of uranium 235 U. In addition, there is no concept of critical mass for a thermonuclear charge, and this limits the possible the power of a nuclear charge is several hundred kilotons. The synthesis makes it possible to achieve a power level of megatons of TNT equivalent. But for this, the nuclei must be brought closer to such a distance at which strong interactions will appear - 10 -15 m. The approach is prevented by electrostatic repulsion between positively charged nuclei. To overcome this barrier, it is necessary to heat the substance to a temperature of tens of millions of degrees (hence the name "thermonuclear reaction"). Upon reaching ultrahigh temperatures and the state of dense ionized plasma, the probability of the onset of a fusion reaction increases sharply. The nuclei of heavy (deuterium, D) and superheavy (tritium, T) isotopes of hydrogen have the greatest chances, therefore the first thermonuclear charges were called "hydrogen". During synthesis, they form the helium isotope 4He. The only thing left to do is to achieve such high temperatures and pressures as are found inside stars. Thermonuclear munitions are divided into two-phase (fission-synthesis) and three-phase (fission-fusion-fission). A single-phase fission is considered a nuclear or "atomic" charge. The first two-phase charge scheme was found in the early 1950s by Ya.B. Zeldovich, A.D. Sakharov and Yu.A. Trutnev in the USSR and E. Teller and S. Ulam in the USA. It was based on the idea of "radiation implosion" - a method in which heating and compression of a thermonuclear charge occur due to the evaporation of the shell surrounding it. In the process, a whole cascade of explosions was obtained - conventional explosives launched an atomic bomb, and an atomic bomb set fire to a thermonuclear one. Lithium-6 deuteride (6 LiD) was then used as thermonuclear fuel. During a nuclear explosion, the 6Li isotope actively captured fission neutrons, decaying into helium and tritium, forming a mixture of deuterium and tritium necessary for the fusion reaction.
On November 22, 1955, the first Soviet thermonuclear bomb with a design yield of about 3 Mt was detonated (by replacing part 6 LiD with passive material, the power was reduced to 1.6 Mt). It was a more advanced weapon than the bulky stationary device blown up by the Americans three years earlier. And on February 23, 1958, already on Novaya Zemlya, they tested the next, more powerful charge designed by Yu.A. Trutnev and Yu.N. Babaev, which became the basis for the further development of domestic thermonuclear charges.
In the three-phase scheme, the thermonuclear charge is also surrounded by a shell of 238 U. Under the influence of high-energy neutrons produced during a thermonuclear explosion, the fission of 238 U nuclei occurs, which makes an additional contribution to the energy of the explosion.
The detonation of nuclear weapons is provided by complex multi-stage systems, including blocking devices, executive, auxiliary, backup units. A testament to their reliability and the strength of their ammunition cases is that none of the many accidents with nuclear weapons that have occurred over 60 years has caused an explosion or radioactive leakage. Bombs burned, got into car and railway accidents, detached from aircraft and fell on land and in the sea, but not a single one exploded spontaneously.
Thermonuclear reactions convert only 1-2% of the mass of the reactant into explosion energy, and this is far from the limit from the point of view of modern physics. Significantly higher powers can be achieved using the annihilation reaction (mutual annihilation of matter and antimatter). But so far, the implementation of such processes on a “macroscale” is the field of theory.
The damaging effect of an air nuclear explosion with a power of 20 kt. For clarity, the damaging factors of a nuclear explosion are "decomposed" into separate "rulers". It is customary to distinguish between zones of moderate (zone A, the dose of radiation received during complete decay, from 40 to 400 r), strong (zone B, 400-1200 r), dangerous (zone C, 1200-4000 r), especially dangerous (zone G, emergency, 4,000–10,000 r) infection
Dead deserts
The damaging factors of nuclear weapons, possible ways to strengthen them, on the one hand, and protect against them, on the other hand, were tested in the course of numerous tests, including with the participation of troops. AT Soviet army conducted two military exercises with the actual use of nuclear weapons - on September 14, 1954 at the Totsk test site (Orenburg region) and on September 10, 1956 at Semipalatinsk. About this in the domestic press in last years many publications have been published in which, for some reason, they missed the fact that eight similar military exercises were held in the United States. One of them - "Desert Rock-IV" - took place at about the same time as Totskoy, in Yucca Flat (Nevada).
1 - initiating nuclear charge (with nuclear fuel divided into parts)
2 - thermonuclear fuel (mixture of D and T)
3 - nuclear fuel (238U)
4 - initiating nuclear charge after detonating the checkers of a conventional explosive
5 - source of neutrons. The radiation caused by the operation of a nuclear charge generates radiation implosion (evaporation) of a shell of 238U, which compresses and ignites the thermonuclear fuel
Jet catapult
Every weapon must contain a way to deliver the ammunition to the target. For nuclear and thermonuclear charges, a lot of such methods have been invented for different types of armed forces and combat arms. Nuclear weapons are usually divided into "strategic" and "tactical". "Strategic offensive weapons" (START) are designed primarily to destroy targets on enemy territory that are most important for its economy and armed forces. The main elements of START are land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs) and strategic bombers. In the United States, this combination is called the "nuclear triad". In the USSR, the main role was assigned to the Rocket Forces strategic purpose, whose grouping of strategic ICBMs served as the main deterrent for the enemy. Missile submarines, considered less vulnerable to an enemy nuclear attack, were assigned to strike back. The bombers were intended to continue the war after the exchange of nuclear strikes. Tactical weapons are battlefield weapons.
Power range
According to the power of nuclear weapons, they are divided into ultra-small (up to 1 kt), small (from 1 to 10 kt), medium (from 10 to 100 kt), large (from 100 kt to 1 Mt), extra-large (over 1 Mt). That is, Hiroshima and Nagasaki are at the bottom of the "medium" ammunition scale.
In the USSR, on October 30, 1961, the most powerful thermonuclear charge was blown up at the Novaya Zemlya test site (the main developers were V.B. Adamsky, Yu.N. Babaev, A.D. Sakharov, Yu.N. Smirnov and Yu.A. Trutnev). The design capacity of the "superbomb" weighing about 26 tons reached 100 Mt, but for testing it was "halved" to 50 Mt, and the detonation at an altitude of 4,000 m and a number of additional measures excluded dangerous radioactive contamination of the area. HELL. Sakharov suggested that the sailors make a giant torpedo with a hundred-megaton charge to strike the ports and coastal cities of the enemy. According to his memoirs: “Rear Admiral P.F. Fokin ... was shocked by the "cannibalistic nature" of the project and noted in a conversation with me that military sailors were accustomed to fighting an armed enemy in open battle and that the very thought of such a massacre was disgusting for him "(quoted by A.B. Koldobsky "Strategic submarine fleet of the USSR and Russia, past, present, future). Prominent nuclear weapons designer L.P. Feoktistov speaks about this idea: “In our circles, it was widely known and caused irony with its unrealizability, and complete rejection due to its blasphemous, deeply inhuman nature.”
The Americans made their most powerful explosion of 15 Mt on March 1, 1954 near Bikini Atoll in pacific ocean. And again, not without consequences for the Japanese - radioactive fallout covered the Japanese trawler "Fukuryu-maru", located more than 200 km from Bikini. 23 fishermen received a high dose of radiation, one died from radiation sickness.
The most "small" tactical nuclear weapon can be considered the American Davy Crocket system of 1961 - 120- and 155-mm recoilless rifles with a nuclear projectile of 0.01 kt. However, the system was soon abandoned. The idea of an “atomic bullet” based on californium-254 (an artificially obtained element with a very low critical mass) was not implemented either.
Nuclear winter
By the end of the 1970s, the nuclear parity of the opposing superpowers in all respects and the impasse of "nuclear strategy" became apparent. And then - very timely - the theory of "nuclear winter" entered the arena. On the Soviet side, academicians N.N. Moiseeva and G.S. Golitsyn, from the American - astronomer K. Sagan. G.S. Golitsyn briefly outlines the consequences of a nuclear war: “Mass fires. The sky is black with smoke. Ashes and smoke absorb solar radiation. The atmosphere heats up, and the surface cools - the sun's rays do not reach it. All fumes related effects are reduced. The monsoons, which carry moisture from the oceans to the continents, cease. The atmosphere becomes dry and cold. All living things die." That is, regardless of the availability of shelters and the level of radiation, survivors of a nuclear war are doomed to die simply from hunger and cold. The theory received its “mathematical” numerical confirmation and excited the minds a lot in the 1980s, although it immediately met with rejection in scientific circles. Many experts agreed that in the theory of nuclear winter, scientific credibility was sacrificed to humanitarian, or rather political, aspirations - to accelerate nuclear disarmament. This explains its popularity.
The limitation of nuclear weapons was quite logical and was not a success of diplomacy and "environmentalists" (which often become just an instrument of current politics), but of military technology. High-precision weapons capable of “putting” a conventional charge with an accuracy of tens of meters at a distance of several hundred kilometers, generators of powerful electromagnetic pulses that disable electronic equipment, volumetric detonating and thermobaric ammunition that create extensive destruction zones, allow solving the same tasks, like tactical nuclear weapons - without the risk of causing a general nuclear catastrophe.
Launch Variations
Guided missiles are the main carrier of nuclear weapons. Intercontinental-range missiles with nuclear warheads are the most formidable component of nuclear arsenals. The warhead (warhead) is delivered to the target in the minimum time, while it is a hard-to-hit target. With increasing accuracy, ICBMs have become a means of destroying well-defended targets, including vital military and civilian targets. Multiple warheads have significantly increased the effectiveness of nuclear missile weapons. So, 20 ammunition of 50 kt is equivalent in efficiency to one of 10 Mt. Separated heads of individual guidance more easily break through the anti-missile defense system (ABM) than a monoblock one. The development of maneuvering warheads, the trajectory of which the enemy cannot calculate, made the work of missile defense even more difficult.
Land-based ICBMs are now installed either in mines or on mobile installations. The mine installation is the most protected and ready for immediate start-up. american rocket the silo-based Minuteman-3 can deliver a multiple warhead with three blocks of 200 kt each to a range of up to 13,000 km, the Russian R-36M can deliver a warhead of 8 blocks of a megaton class to a distance of 10,000 km (a single-block warhead is also possible). A "mortar" launch (without a bright engine torch), a powerful set of means to overcome missile defense enhance the formidable appearance of the R-36M and N missiles, called SS-18 "Satan" in the West. But the mine is stationary, no matter how you hide it, and over time, its exact coordinates will be in the flight program of enemy warheads. Another option for basing strategic missiles is a mobile complex, with which you can keep the enemy in the dark about the launch site. For example, a combat railway missile system, disguised as a regular train with passenger and refrigerator cars. Rocket launch (for example, RT-23UTTKh with 10 warheads and a firing range of up to 10,000 km) can be made from any part of the path railway. Heavy all-terrain wheeled chassis made it possible to place ICBM launchers on them. For example, the Russian universal rocket "Topol-M" (RS-12M2 or SS-27) with a monoblock warhead and a range of up to 10,000 km, put on combat duty in the late 1990s, is intended for mine and mobile ground installations, it is provided its basing and on submarines. The warhead of this missile, weighing 1.2 tons, has a capacity of 550 kt, that is, each kilogram of a nuclear charge in this case is equivalent to almost 500 tons of explosives.
The main way to increase the surprise of the strike and leave the enemy less time to react is to shorten the flight time by placing launchers closer to him. The opposing sides were very actively engaged in this, creating operational-tactical missiles. The treaty, signed by M. Gorbachev and R. Reagan on December 8, 1987, led to a reduction in medium-range (from 1,000 to 5,500 km) and shorter-range (from 500 to 1,000 km) missiles. Moreover, at the insistence of the Americans, the Oka complex with a range of no more than 400 km was included in the Treaty, which did not fall under restrictions: the unique complex went under the knife. But now a new Russian Iskander complex has already been developed.
The medium-range missiles that fell under the reduction reached the target in just 6-8 minutes of flight, while the intercontinental ballistic missiles that remained in service usually take 25-35 minutes to travel.
Cruise missiles have been playing an important role in American nuclear strategy for thirty years now. Their advantages are high accuracy, secrecy of flight at low altitudes with terrain envelope, low radar visibility and the possibility of delivering a massive strike from several directions. Launched from a surface ship or submarine, a Tomahawk cruise missile can carry a nuclear or conventional warhead up to 2,500 km in about 2.5 hours.
Rocket launcher underwater
The basis of the naval strategic forces are nuclear submarines with submarine-launched missile systems. Despite the advanced systems for tracking submarines, mobile "underwater rocket launchers" retain the advantages of stealth and surprise actions. An underwater-launched ballistic missile is a unique product in terms of placement and use. A long firing range with a wide autonomy of navigation allows the boats to operate closer to their shores, reducing the risk that the enemy will destroy the boat before the missiles are launched.
Two SLBM complexes can be compared. The Soviet nuclear submarine of the Akula type carries 20 R-39 missiles, each with 10 individually targetable warheads with a capacity of 100 kt each, a firing range of 10,000 km. An American boat of the Ohio type carries 24 Trident-D5 missiles, each can deliver 8 warheads of 475 kt, or 14 of 100-150 kt, to 11,000-12,000 km.
neutron bomb
A variety of thermonuclear weapons became neutron munitions, characterized by an increased output of initial radiation. Most of the energy of the explosion "goes" into penetrating radiation, and the main contribution to it is made by fast neutrons. So, if we assume that during an air explosion of a conventional nuclear weapon, 50% of the energy "leaves" into a shock wave, 30-35% into light radiation and EMP, 5-10% into penetrating radiation, and the rest into radioactive contamination, then in neutron (for the case when its initiating and main charges make an equal contribution to energy generation) 40, 25, 30 and 5%, respectively, are spent on the same factors. Result: with an above-ground explosion of a neutron munition of 1 kt, the destruction of structures occurs within a radius of up to 430 m, forest fires - up to 340 m, but the radius in which a person instantly “grabs” 800 rad is 760 m, 100 rad (radiation sickness) - 1,650 m. The zone of destruction of manpower is growing, the zone of destruction is decreasing. In the United States, neutron munitions were made tactical - in the form of, say, 203- and 155-mm projectiles with a yield of 1 to 10 kt.
The strategy of "bombers"
Strategic bombers - American B-52, Soviet Tu-95 and M4 - were the first intercontinental means of nuclear attack. ICBMs have significantly supplanted them in this role. With the armament of strategic bombers with cruise missiles - like the American AGM-86B or the Soviet Kh-55 (both carry a charge of up to 200 kt at a distance of up to 2,500 km), which allow them to strike without entering the enemy air defense coverage area - their importance has increased.
The aviation is also armed with such a “simple” means as a free-falling nuclear bomb, for example, the American B-61/83 with a charge of 0.3 to 170 kt. Nuclear warheads were created for air defense and missile defense systems, but with the improvement of missiles and conventional warheads, such charges were abandoned. On the other hand, they decided to “raise higher” nuclear explosive devices - to the space echelon of missile defense. One of its long-planned elements is laser installations, in which nuclear explosion serves as a powerful pulsed energy source for pumping several x-ray lasers at once.
Tactical nuclear weapons are also available in various branches of the armed forces and combat arms. Nuclear bombs, for example, can be carried not only by strategic bombers, but also by many front-line or carrier-based aircraft.
For strikes against ports, naval bases, and large ships, the Navy had nuclear torpedoes, such as the Soviet 533-mm T-5 with a charge of 10 kt and the American Mk 45 ASTOR equal in charge power. In turn, anti-submarine aircraft could carry nuclear depth charges.
The Russian tactical mobile missile system "Tochka-U" (on a floating chassis) delivers a nuclear or conventional charge to a range of "only" up to 120 km.
The first samples of atomic artillery were the bulky American 280-mm cannon of 1953 and the Soviet 406-mm cannon and 420-mm mortar that appeared a little later. Subsequently, they preferred to create "special projectiles" for conventional ground artillery systems - for 155-mm and 203-mm howitzers in the USA (with a capacity of 1 to 10 kt), 152-mm howitzers and cannons, 203-mm cannons and 240-mm mortars in the USSR . Nuclear special projectiles were also created for naval artillery, for example, an American 406-mm projectile with 20 kt power (“one Hiroshima” in a heavy artillery projectile).
nuclear backpack
The “nuclear backpacks” that attract so much attention were not created at all to be placed under the White House or the Kremlin. These are engineering land mines that serve to create barriers due to the formation of craters, blockages in mountain ranges and zones of destruction and flooding in combination with radioactive fallout (during a ground explosion) or residual radiation in the crater area (during an underground explosion). Moreover, in one "backpack" there can be both a whole nuclear explosive device of an ultra-small caliber, and part of a device of greater power. The American "backpack" Mk-54 with a capacity of 1 kiloton weighs only 68 kg.
Land mines were also developed for other purposes. In the 1960s, for example, the Americans put forward the idea of creating a so-called nuclear mine belt along the border between the GDR and the FRG. And the British were going to lay powerful nuclear charges in the event of leaving their bases in Germany, which were supposed to be blown up by radio signal already in the rear of the “advancing Soviet armada”.
The danger of nuclear war has given rise to different countries government construction programs colossal in scale and cost - underground shelters, command posts, storage facilities, transport communications and communication systems. The appearance and development of nuclear missile weapons is largely due to the development of near-Earth outer space. So, the famous royal R-7 rocket, which put into orbit both the first artificial satellite and the Vostok-1 spacecraft, was designed to “throw” a thermonuclear charge. Much later, the R-36M rocket became the basis for the Zenit-1 and Zenit-2 launch vehicles. But the impact of nuclear weapons was much wider. The very presence of intercontinental-range nuclear missile weapons made it necessary to create a complex of reconnaissance and control facilities covering almost the entire planet and based on a constellation of orbiting satellites. Work on thermonuclear weapons contributed to the development of the physics of high pressures and temperatures, significantly advanced astrophysics, explaining a number of processes occurring in the Universe.
2000 nuclear explosions
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: Dominik; 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.
AN602 (aka Tsar Bomba, aka Kuzkina Mother) is a thermonuclear aerial bomb developed in the USSR in 1954-1961. a group of nuclear physicists under the leadership of Academician of the Academy of Sciences of the USSR IV Kurchatov. The most powerful explosive device in the history of mankind. According to various sources, it had from 57 to 58.6 megatons of TNT equivalent. The bomb tests took place on October 30, 1961. (Wiki media)
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 the order of 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. 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 clumps and jets of plasma, like a piston, compress the air in front of them and form a shock wave inside the sphere - an internal shock, which differs from the usual 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 one near its boundary, and somewhere from 36-37 m a density increase wave 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: 0.000001s. Distance: 34m Temperature: 2 million °C. The internal shock and vapors of the bomb are located in a layer of 8-12 m from the place of explosion, 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 velocity 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. A reinforced concrete bunker with walls 2 m thick was located 15 m from the epicenter or 5–6 m from the base of the tower with a charge. To accommodate scientific equipment, it was destroyed from above, covered with a large mound of earth 8 m thick.
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 during an explosion large mass 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 shock 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: 0.015s. 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 of 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 fiery sphere at this time reaches maximum dimensions(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 mushroom.
Time: 2.6c. Distance: 2200m Temperature: 7.5 thousand ° C. Severe defeats 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 is the design pressure of the shock wave for the design of 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, non-dangerous radiation injury, but with the unsanitary conditions and heavy physical and psychological stress accompanying the disaster, the 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 - in beachwear, death is possible. Destruction of reinforced glazing. Uprooting large trees. The zone of individual 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 "leaning" 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 trail.
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. Effective time half the deposition of radioactive substances 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 below indicates that the site has been designated a National Historic Landmark. (Photo: Wikicommons)
Radioactivity. Law radioactive decay. Impact of ionizing radiation on biological objects. Unit of measure for radioactivity.
Radioactivity is the ability of atoms of certain isotopes to spontaneously decay by emitting radiation. For the first time, such radiation emitted by uranium was discovered by Becquerel, therefore, at first, radioactive radiation was called Becquerel rays. The main type of radioactive decay is the ejection of alpha particles from the nucleus of an atom - alpha decay (see Alpha radiation) or beta particles - beta decay (see Beta radiation).
The most important characteristic of radioactivity is the law of radioactive decay, which shows how (on average) the number N of radioactive nuclei in a sample changes with time t
N(t) \u003d N 0 e -λt,
where N 0 is the number of initial nuclei at the initial moment (the moment of their formation or the beginning of observation), and λ is the decay constant (the probability of decay of a radioactive nucleus per unit time). This constant can be used to express the average lifetime of a radioactive nucleus τ = 1/λ, as well as the half-life T 1/2 = ln2/τ. The half-life clearly characterizes the decay rate, showing how long it takes for the number of radioactive nuclei in the sample to be halved.
Units.
| RADIOACTIVITY UNITS | ||
| Becquerel (Bq, Vq); Curie (Ki, Si) | 1 Bq = 1 disintegration per second. 1 Ki \u003d 3.7 x 10 10 Bq | Radionuclide activity units. Represent the number of decays per unit time. |
| Gray (Gr, Gu); Glad (rad, rad) | 1 Gy = 1 J/kg 1 rad = 0.01 Gy | units of absorbed dose. They represent the amount of energy of ionizing radiation absorbed by a unit mass of a physical body, for example, body tissues. |
| Sievert (Sv, Sv) Rem (ber, rem) - "X-ray biological equivalent" | 1 Sv = 1Gy = 1J/kg (for beta and gamma) 1 µSv = 1/1000000 Sv 1 ber = 0.01 Sv = 10mSv | Units of equivalent dose. They are a unit of absorbed dose multiplied by a factor that takes into account the unequal danger of different types of ionizing radiation. |
| Gray per hour (Gy/h); Sievert per hour (Sv/h); Roentgen per hour (R/h) | 1 Gy/h = 1 Sv/h = 100 R/h (for beta and gamma) 1 µ Sv/h = 1 µGy/h = 100 µR/h 1 µR/h = 1/1000000 R/h | Dose rate units. Represent the dose received by the body per unit of time. |
Impact of ionizing radiation on biological objects.
As a result of the impact of ionizing radiation on the human body, complex physical, chemical and biochemical processes can occur in the tissues.
When radioactive substances enter the body, the damaging effect is mainly produced by alpha sources, and then by beta sources, i.e. in the reverse order to external irradiation. Alpha particles, which have a low ionization density, destroy the mucous membrane, which is a weak defense. internal organs compared to the outer skin.
There are three ways in which radioactive substances enter the body: by inhalation of air contaminated with radioactive substances, through contaminated food or water, through the skin, and through infection of open wounds. The first way is the most dangerous, because, firstly, the volume of pulmonary ventilation is very large, and secondly, the values of the assimilation coefficient in the lungs are higher.
Dust particles, on which radioactive isotopes are sorbed, partially settle in the oral cavity and nasopharynx when air is inhaled through the upper respiratory tract. From here, the dust enters the digestive tract. The rest of the particles enter the lungs. The degree of retention of aerosols in the lungs depends on their dispersion. About 20% of all particles are retained in the lungs; as the size of aerosols decreases, the delay increases to 70%.
When radioactive substances are absorbed from the gastrointestinal tract, the resorption coefficient is important, which characterizes the proportion of the substance that enters the blood from the gastrointestinal tract. Depending on the nature of the isotope, the coefficient varies over a wide range: from hundredths of a percent (for zirconium, niobium) to several tens of percent (hydrogen, alkaline earth elements). Resorption through intact skin is 200-300 times less than through the gastrointestinal tract, and, as a rule, does not play a significant role.
When radioactive substances enter the body in any way, they are found in the blood in a few minutes. If the intake of radioactive substances was a single one, then their concentration in the blood first increases to a maximum, and then decreases within 15-20 days.
Blood concentrations of long-lived isotopes can subsequently be maintained at almost the same level for a long time due to the reverse washing out of deposited substances. The effect of ionizing radiation on a cell is the result of complex interrelated and interdependent transformations. According to A.M. Kuzin, radiation damage to cells occurs in three stages. At the first stage, radiation affects complex macromolecular formations, ionizing and exciting them. This is the physical stage of radiation exposure. The second stage is chemical transformations. They correspond to the processes of interaction of protein radicals, nucleic acids and lipids with water, oxygen, water radicals and the formation of organic peroxides. The radicals that appear in the layers of ordered protein molecules interact with the formation of "crosslinks", as a result of which the structure of biomembranes is disturbed. Due to damage to lysosomal membranes, there is an increase in activity and the release of enzymes that, by diffusion, reach any cell organelle and easily penetrate into it, causing its lysis.
The final effect of irradiation is the result not only of the primary damage to cells, but also of subsequent repair processes. It is assumed that a significant part of the primary damage in the cell occurs in the form of so-called potential damage, which can be realized in the absence of recovery processes. The implementation of these processes is facilitated by the processes of biosynthesis of proteins and nucleic acids. Until the realization of potential damage has occurred, the cell can "repair" in them. This is thought to be related to enzymatic reactions and is driven by energy metabolism. It is believed that this phenomenon is based on the activity of systems that, under normal conditions, regulate the intensity of the natural mutation process.
The mutagenic effect of ionizing radiation was first established by Russian scientists R.A. Nadson and R.S. Filippov in 1925 in experiments on yeast. In 1927, this discovery was confirmed by R. Meller on a classic genetic object - Drosophila.
Ionizing radiation is capable of causing all kinds of hereditary changes. The spectrum of mutations induced by irradiation does not differ from the spectrum of spontaneous mutations.
Recent studies of the Kyiv Institute of Neurosurgery have shown that radiation, even in small quantities, at doses of tens of rem, has the strongest effect on nerve cells - neurons. But neurons do not die from direct exposure to radiation. As it turned out, as a result of exposure to radiation, the majority of liquidators of the Chernobyl NPP observed "post-radiation encephalopathy." General disorders in the body under the influence of radiation leads to a change in metabolism, which entail pathological changes in the brain.
2. Principles for the design of nuclear weapons. The main opportunities for further development and improvement of nuclear weapons.
Nuclear munitions are called missile warheads equipped with nuclear (thermonuclear) charges, aerial bombs, artillery shells, torpedoes and engineering guided mines (nuclear land mines).
The main elements of nuclear weapons are: a nuclear charge, detonation sensors, an automation system, an electrical power source and a body.
The case serves to arrange all the elements of the ammunition, protect them from mechanical and thermal damage, give the ammunition the necessary ballistic shape, and also to increase the utilization factor of nuclear fuel.
Detonation sensors (explosive devices) are designed to give a signal to activate a nuclear charge. They can be contact and remote (non-contact) types.
Contact sensors are triggered at the moment the ammunition meets an obstacle, and remote sensors - at a given height (depth) from the surface of the earth (water).
Remote sensors, depending on the type and purpose of a nuclear weapon, can be temporary, inertial, barometric, radar, hydrostatic, etc.
The automation system includes a safety system, an automation unit and an emergency detonation system.
The safety system eliminates the possibility of an accidental explosion of a nuclear charge during routine maintenance, storage of ammunition and during its flight on a trajectory.
The automation unit is triggered by signals from detonation sensors and is designed to generate a high-voltage electrical impulse to actuate a nuclear charge.
The emergency detonation system serves to self-destruct the ammunition without a nuclear explosion in case it deviates from a given trajectory.
The power source of the entire electrical system of the ammunition are rechargeable batteries various types, which have a one-time action and are brought into working condition immediately before its combat use.
A nuclear charge is a device for the implementation of a nuclear explosion. Below, we will consider the existing types of nuclear charges and their fundamental structure.
Nuclear charges
Devices designed to carry out the explosive process of releasing intranuclear energy are called nuclear charges.
There are two main types of nuclear weapons:
1 - charges, the explosion energy of which is due to a chain reaction of fissile substances transferred to a supercritical state - atomic charges;
2 - charges, the explosion energy of which is due to the thermonuclear fusion reaction of nuclei, - thermonuclear charges.
Atomic charges. The main element of atomic charges is fissile material (nuclear explosive).
Prior to the explosion, the mass of nuclear explosives is in a subcritical state. To carry out a nuclear explosion, it is transferred to a supercritical state. Two types of devices are used to ensure the formation of a supercritical mass: cannon and implosive.
In cannon-type charges, the nuclear explosive consists of two or more parts, the mass of which is individually less than the critical one, which ensures the exclusion of the spontaneous onset of a nuclear chain reaction. When a nuclear explosion is carried out, individual parts of the nuclear explosive unit under the action of the energy of the explosion of a conventional explosive material are combined into one whole and the total mass of the nuclear explosive material becomes more critical, which creates conditions for an explosive chain reaction.
The transfer of the charge to the supercritical state is carried out by the action of a powder charge. The probability of obtaining the calculated explosion power in such charges depends on the speed of approach of the parts of the nuclear explosive. If the speed of approach is insufficient, the criticality coefficient may become somewhat greater than unity even before the moment of direct contact of the parts of the nuclear explosive. In this case, the reaction can start from one initial fission center under the influence of, for example, a spontaneous fission neutron, resulting in an inferior explosion with a small nuclear fuel utilization factor.
The advantage of cannon-type nuclear charges is the simplicity of design, small dimensions and weight, high mechanical strength, which makes it possible to create small-sized nuclear munitions (artillery shells, nuclear mines, etc.) on their basis.
In implosion-type charges, to create a supercritical mass, the effect of implosion is used - the all-round compression of a nuclear explosive by the explosion force of a conventional explosive, which leads to a sharp increase in its density.
The effect of implosion creates a huge concentration of energy in the NHE zone and makes it possible to reach a pressure exceeding millions of atmospheres, which leads to an increase in the NHE density by 2–3 times and a decrease in the critical mass by 4–9 times.
For guaranteed imitation of a fission chain reaction and its acceleration, a powerful neutron pulse must be applied from an artificial neutron source at the moment of the highest implosion.
The advantage of implosion-type atomic charges is a higher utilization rate of nuclear explosives, as well as the ability, within certain limits, to change the power of a nuclear explosion using a special switch.
The disadvantages of atomic charges include large mass and dimensions, low mechanical strength and sensitivity to temperature conditions.
Thermonuclear charges In charges of this type, the conditions for a fusion reaction are created by detonating an atomic charge (detonator) from uranium-235, plutonium-239 or californium-251. Thermonuclear charges can be neutron and combined
In thermonuclear neutron charges, deuterium and tritium in pure form or in the form of metal hydrides are used as thermonuclear fuel. The "fuse" of the reaction is highly enriched plutonium-239 or californium-251, which have a relatively small critical mass. This allows you to increase the coefficient of thermonuclear ammunition.
Thermonuclear combined charges use lithium deuteride (LiD) as a thermonuclear fuel. For the "fuse" of the fusion reaction is the fission reaction of uranium-235. In order to obtain high-energy neutrons for the reaction (1.18), already at the very beginning of the nuclear process, an ampoule with tritium (1H3) is placed in the nuclear charge. Fission neutrons are necessary to obtain tritium from lithium in the initial period of the reaction. neutrons released during the fusion reactions of deuterium and tritium, as well as the fission of uranium-238 (the most common and cheapest natural uranium), which specially surrounds the reaction zone in the form of a shell. The presence of such a shell allows not only to carry out an avalanche-like thermonuclear reaction, but also to obtain additional energy explosion, since at a high flux density of neutrons with an energy of more than 10 MeV, the fission reaction of uranium-238 nuclei proceeds quite efficiently. At the same time, the amount of energy released becomes very large and in ammunition of large and extra-large calibers can be up to 80% of the total energy of a combined thermonuclear munition a.
Classification of nuclear weapons
Nuclear munitions are classified by the power of the released energy of the nuclear charge, as well as by the type of nuclear reaction used in them. To characterize the power of the munition, the concept of "TNT equivalent" is used - this is such a mass of TNT, the explosion energy of which is the swarm of energy released during an air explosion of a nuclear warhead (charge) The TNT equivalent is denoted by the letter § and is measured in tons (t), thousand tons (kg), million tons (Mt)
In terms of power, nuclear weapons are conventionally divided into five calibers.
nuclear weapon caliber
TNT equivalent thousand tons
Ultra Small Up to 1
Average 10-100
Large 100-1000
Extra Large Over 1000
Classification of nuclear explosions by type and power. The damaging factors of a nuclear explosion.
Depending on the tasks solved with the use of nuclear weapons, nuclear explosions can be carried out in the air, on the surface of the earth and water, underground and water. In accordance with this, air, ground (surface) and underground (underwater) explosions are distinguished (Figure 3.1).
An air nuclear explosion is an explosion produced at a height of up to 10 km, when the luminous area does not touch the ground (water). Air explosions are divided into low and high. Strong radioactive contamination of the area is formed only near the epicenters of low air explosions. Infection of the area following the trail of a cloud of significant impact on actions personnel does not render. The shock wave, light radiation, penetrating radiation, and EMP manifest themselves most fully in an air nuclear explosion.
Ground (surface) nuclear explosion is an explosion produced on the surface of the earth (water), in which the luminous area touches the surface of the earth (water), and the dust (water) column from the moment of formation is connected with the explosion cloud. 50 A characteristic feature of a ground (surface) nuclear explosion is a strong radioactive contamination of the terrain (water) both in the area of the explosion and in the direction of the explosion cloud. The damaging factors of this explosion are the shock wave, light radiation, penetrating radiation, radioactive contamination of the area and EMP.
An underground (underwater) nuclear explosion is an explosion produced underground (under water) and is characterized by the release of a large amount of soil (water) mixed with nuclear explosive products (fragments of uranium-235 or plutonium-239 fission) . The damaging and destructive effect of an underground nuclear explosion is determined mainly by seismic-explosive waves (the main damaging factor), the formation of a funnel in the ground and strong radioactive contamination of the area. Light emission and penetrating radiation are absent. Characteristic of an underwater explosion is the formation of a sultan (column of water), the basic wave formed during the collapse of the sultan (column of water).
An air nuclear explosion begins with a short blinding flash, the light from which can be observed at a distance of several tens and hundreds of kilometers. Following the flash, a luminous area appears in the form of a sphere or hemisphere (with a ground explosion), which is a source of powerful light radiation. At the same time, a powerful flux of gamma radiation and neutrons propagates from the explosion zone into the environment, which are formed during a nuclear chain reaction and during the decay of radioactive fragments of nuclear charge fission. Gamma rays and neutrons emitted during a nuclear explosion are called penetrating radiation. Under the action of instantaneous gamma radiation, the ionization of atoms occurs environment, which leads to the appearance of electric and magnetic fields. These fields, due to their short duration of action, are commonly called the electromagnetic pulse of a nuclear explosion.
At the center of a nuclear explosion, the temperature instantly rises to several million degrees, as a result of which the substance of the charge turns into a high-temperature plasma emitting x-rays. The pressure of gaseous products initially reaches several billion atmospheres. The sphere of incandescent gases of the glowing region, seeking to expand, compresses the adjacent layers of air, creates a sharp pressure drop at the boundary of the compressed layer, and forms a shock wave that propagates from the center of the explosion in various directions. Since the density of the gases that make up the fireball is much lower than the density of the surrounding air, the ball rises rapidly. In this case, a mushroom-shaped cloud is formed, containing gases, water vapor, small particles of soil and a huge amount of radioactive products of the explosion. Upon reaching the maximum height, the cloud is transported over long distances under the action of air currents, dissipates, and radioactive products fall on the earth's surface, creating radioactive contamination of the area and objects.
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-rise (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:
Shockwave (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);
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 matter 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 converted from chemical element into powerful explosives.
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 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 hydrogen molecules evaporated under the influence of high temperatures, carbon dioxide and nitrogen.
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 70-80 years In a similar way solved national economic problems, 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 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.
