What does an atomic weapon look like? The explosion of an atomic bomb and its mechanism of action

The one who invented the atomic bomb could not even imagine what tragic consequences this miracle invention of the 20th century could lead to. It was a very long journey before the residents of the Japanese cities of Hiroshima and Nagasaki experienced this superweapon.

A start

In April 1903, Paul Langevin's friends gathered in the Parisian garden of France. The reason was the defense of the dissertation of the young and talented scientist Marie Curie. Among the distinguished guests was the famous English physicist Sir Ernest Rutherford. In the midst of the fun, the lights were turned off. announced to everyone that there would be a surprise. With a solemn look, Pierre Curie brought in a small tube with radium salts, which shone with a green light, causing extraordinary delight among those present. Subsequently, the guests heatedly discussed the future of this phenomenon. Everyone agreed that radium would solve the acute problem of energy shortages. This inspired everyone for new research and further prospects. If they had been told then that laboratory works with radioactive elements will lay the foundation for the terrible weapons of the 20th century, it is unknown what their reaction would have been. It was then that the story of the atomic bomb began, killing hundreds of thousands of Japanese civilians.

Playing ahead

On December 17, 1938, the German scientist Otto Gann obtained irrefutable evidence of the decay of uranium into smaller elementary particles. Essentially, he managed to split the atom. In the scientific world, this was regarded as a new milestone in the history of mankind. Otto Gann did not share the political views of the Third Reich. Therefore, in the same year, 1938, the scientist was forced to move to Stockholm, where, together with Friedrich Strassmann, he continued his scientific research. Fearing that Nazi Germany will be the first to receive terrible weapons, he writes a letter warning about this. The news of a possible advance greatly alarmed the US government. The Americans began to act quickly and decisively.

Who created the atomic bomb? American project

Even before the group, many of whom were refugees from the Nazi regime in Europe, was tasked with the development of nuclear weapons. Initial research, it is worth noting, was carried out in Nazi Germany. In 1940, the government of the United States of America began funding its own program to develop atomic weapons. An incredible sum of two and a half billion dollars was allocated to implement the project. They were invited to implement this secret project outstanding physicists XX century, among whom there were more than ten Nobel laureates. In total, about 130 thousand employees were involved, among whom were not only military personnel, but also civilians. The development team was headed by Colonel Leslie Richard Groves, and Robert Oppenheimer became the scientific director. He is the man who invented the atomic bomb. A special secret engineering building was built in the Manhattan area, which we know under the code name “Manhattan Project”. Over the next few years, scientists from the secret project worked on the problem of nuclear fission of uranium and plutonium.

The non-peaceful atom of Igor Kurchatov

Today, every schoolchild will be able to answer the question of who invented the atomic bomb in the Soviet Union. And then, in the early 30s of the last century, no one knew this.

In 1932, Academician Igor Vasilyevich Kurchatov was one of the first in the world to begin studying the atomic nucleus. Gathering like-minded people around him, Igor Vasilyevich created the first cyclotron in Europe in 1937. In the same year, he and his like-minded people created the first artificial nuclei.

In 1939, I.V. Kurchatov began studying a new direction - nuclear physics. After several laboratory successes in studying this phenomenon, the scientist receives at his disposal a secret research center, which was named “Laboratory No. 2”. Nowadays this classified object is called "Arzamas-16".

The target direction of this center was the serious research and creation of nuclear weapons. Now it becomes obvious who created the atomic bomb in the Soviet Union. His team then consisted of only ten people.

There will be an atomic bomb

By the end of 1945, Igor Vasilyevich Kurchatov managed to assemble a serious team of scientists numbering more than a hundred people. The best minds of various scientific specializations came to the laboratory from all over the country to create atomic weapons. After the Americans dropped an atomic bomb on Hiroshima, Soviet scientists realized that this could be done with the Soviet Union. "Laboratory No. 2" receives from the country's leadership a sharp increase in funding and a large influx of qualified personnel. Lavrenty Pavlovich Beria is appointed responsible for such an important project. The enormous efforts of Soviet scientists have borne fruit.

Semipalatinsk test site

The atomic bomb in the USSR was first tested at the test site in Semipalatinsk (Kazakhstan). On August 29, 1949, a nuclear device with a yield of 22 kilotons shook the Kazakh soil. Nobel laureate physicist Otto Hanz said: “This is good news. If Russia has atomic weapons, then there will be no war.” It was this atomic bomb in the USSR, encrypted as product No. 501, or RDS-1, that eliminated the US monopoly on nuclear weapons.

Atomic bomb. Year 1945

In the early morning of July 16, the Manhattan Project conducted its first successful test of an atomic device - a plutonium bomb - at the Alamogordo test site in New Mexico, USA.

The money invested in the project was well spent. The first in the history of mankind was carried out at 5:30 am.

“We have done the devil’s work,” the one who invented the atomic bomb in the USA, later called “the father of the atomic bomb,” will say later.

Japan will not capitulate

By the time of the final and successful testing of the atomic bomb, Soviet troops and allies had finally defeated Nazi Germany. However, there was one state that promised to fight to the end for dominance in the Pacific Ocean. From mid-April to mid-July 1945, the Japanese army repeatedly carried out air strikes against allied forces, thereby inflicting heavy losses on the US army. At the end of July 1945, the militaristic Japanese government rejected the Allied demand for surrender under the Potsdam Declaration. It stated, in particular, that in case of disobedience, the Japanese army would face rapid and complete destruction.

The President agrees

The American government kept its word and began a targeted bombing of Japanese military positions. Air strikes did not bring the desired result, and US President Harry Truman decides to invade Japanese territory by American troops. However, the military command dissuades its president from such a decision, citing the fact that an American invasion would entail a large number of victims.

At the suggestion of Henry Lewis Stimson and Dwight David Eisenhower, it was decided to use more effective method end of the war. A big supporter of the atomic bomb, US Presidential Secretary James Francis Byrnes, believed that the bombing of Japanese territories would finally end the war and put the United States in a dominant position, which would have a positive impact on the further course of events in the post-war world. Thus, US President Harry Truman was convinced that this was the only correct option.

Atomic bomb. Hiroshima

The small Japanese city of Hiroshima with a population of just over 350 thousand people, located five hundred miles from the Japanese capital Tokyo, was chosen as the first target. After the modified B-29 Enola Gay bomber arrived at the US naval base on Tinian Island, an atomic bomb was installed on board the aircraft. Hiroshima was to experience the effects of 9 thousand pounds of uranium-235.

This never-before-seen weapon was intended for civilians in a small Japanese town. The bomber's commander was Colonel Paul Warfield Tibbetts Jr. The US atomic bomb bore the cynical name “Baby”. On the morning of August 6, 1945, at approximately 8:15 a.m., the American “Little” was dropped on Hiroshima, Japan. About 15 thousand tons of TNT destroyed all life within a radius of five square miles. One hundred and forty thousand city residents died in a matter of seconds. The surviving Japanese died a painful death from radiation sickness.

They were destroyed by the American atomic “Baby”. However, the devastation of Hiroshima did not cause the immediate surrender of Japan, as everyone expected. Then it was decided to carry out another bombing of Japanese territory.

Nagasaki. The sky is on fire

The American atomic bomb “Fat Man” was installed on board a B-29 aircraft on August 9, 1945, still there, at the US naval base in Tinian. This time the commander of the aircraft was Major Charles Sweeney. Initially, the strategic target was the city of Kokura.

However, weather conditions did not allow the plan to be carried out; heavy clouds interfered. Charles Sweeney went into the second round. At 11:02 a.m., the American nuclear “Fat Man” engulfed Nagasaki. It was a more powerful destructive air strike, which was several times stronger than the bombing in Hiroshima. Nagasaki tested an atomic weapon weighing about 10 thousand pounds and 22 kilotons of TNT.

The geographic location of the Japanese city reduced the expected effect. The thing is that the city is located in a narrow valley between the mountains. Therefore, the destruction of 2.6 square miles did not reveal the full potential of American weapons. The Nagasaki atomic bomb test is considered the failed Manhattan Project.

Japan surrendered

At noon on August 15, 1945, Emperor Hirohito announced his country's surrender in a radio address to the people of Japan. This news quickly spread around the world. Celebrations began in the United States of America to mark the victory over Japan. The people rejoiced.

On September 2, 1945, a formal agreement to end the war was signed aboard the American battleship Missouri anchored in Tokyo Bay. Thus ended the most brutal and bloody war in human history.

For six long years, the world community has been moving towards this significant date - since September 1, 1939, when the first shots of Nazi Germany were fired on the territory of Poland.

Peaceful atom

In total, 124 nuclear explosions were carried out in the Soviet Union. What is characteristic is that all of them were carried out for the benefit of the national economy. Only three of them were accidents that resulted in the leakage of radioactive elements. Programs for the use of peaceful atoms were implemented in only two countries - the USA and the Soviet Union. Nuclear peaceful energy also knows an example of a global catastrophe, when a reactor exploded at the fourth power unit of the Chernobyl nuclear power plant.

The world of the atom is so fantastic that understanding it requires a radical break in the usual concepts of space and time. Atoms are so small that if a drop of water could be enlarged to the size of the Earth, each atom in that drop would be smaller than an orange. In fact, one drop of water consists of 6000 billion billion (6000000000000000000000) hydrogen and oxygen atoms. And yet, despite its microscopic size, the atom has a structure to some extent similar to the structure of our solar system. In its incomprehensibly small center, the radius of which is less than one trillionth of a centimeter, there is a relatively huge “sun” - the nucleus of an atom.

Tiny “planets” - electrons - revolve around this atomic “sun”. The nucleus consists of the two main building blocks of the Universe - protons and neutrons (they have a unifying name - nucleons). An electron and a proton are charged particles, and the amount of charge in each of them is exactly the same, but the charges differ in sign: the proton is always positively charged, and the electron is negatively charged. The neutron does not carry an electrical charge and, as a result, has a very high permeability.

In the atomic scale of measurements, the mass of a proton and a neutron is taken as unity. The atomic weight of any chemical element therefore depends on the number of protons and neutrons contained in its nucleus. For example, a hydrogen atom, with a nucleus consisting of only one proton, has an atomic mass of 1. A helium atom, with a nucleus of two protons and two neutrons, has an atomic mass of 4.

The nuclei of atoms of the same element always contain the same number of protons, but the number of neutrons may vary. Atoms having nuclei with the same number protons, but differing in the number of neutrons and belonging to varieties of the same element, are called isotopes. To distinguish them from each other, a number is assigned to the symbol of the element equal to the sum of all particles in the nucleus of a given isotope.

The question may arise: why does the nucleus of an atom not fall apart? After all, the protons included in it are electrically charged particles with the same charge, which must repel each other with great force. This is explained by the fact that inside the nucleus there are also so-called intranuclear forces that attract nuclear particles to each other. These forces compensate for the repulsive forces of protons and prevent the nucleus from spontaneously flying apart.

Intranuclear forces are very strong, but act only at very close distances. Therefore, the nuclei of heavy elements, consisting of hundreds of nucleons, turn out to be unstable. The particles of the nucleus are in continuous motion here (within the volume of the nucleus), and if you add some additional quantity energy, they can overcome internal forces - the core will split into parts. The amount of this excess energy is called excitation energy. Among the isotopes of heavy elements, there are those that seem to be on the very verge of self-disintegration. Just a small “push” is enough, for example, a simple hit of a neutron into the nucleus (and it does not even have to accelerate to high speed) for the nuclear fission reaction to occur. Some of these “fissile” isotopes were later learned to be produced artificially. In nature, there is only one such isotope - uranium-235.

Uranus was discovered in 1783 by Klaproth, who isolated it from uranium tar and named it after the recently discovered planet Uranus. As it turned out later, it was, in fact, not uranium itself, but its oxide. Pure uranium, a silvery-white metal, was obtained
only in 1842 Peligo. The new element did not have any remarkable properties and did not attract attention until 1896, when Becquerel discovered the phenomenon of radioactivity in uranium salts. After this, uranium became the object of scientific research and experimentation, but still had no practical use.

When in the first third of the 20th century the structure of the atomic nucleus became more or less clear to physicists, they first of all tried to fulfill the long-standing dream of alchemists - they tried to transform one chemical element to another. In 1934, French researchers, the spouses Frederic and Irene Joliot-Curie, reported to the French Academy of Sciences about the following experience: when bombarding aluminum plates with alpha particles (nuclei of a helium atom), aluminum atoms turned into phosphorus atoms, but not ordinary ones, but radioactive ones, which in turn became into a stable isotope of silicon. Thus, an aluminum atom, having added one proton and two neutrons, turned into a heavier silicon atom.

This experience suggested that if you “bombard” the nuclei of the heaviest element existing in nature - uranium - with neutrons, you can obtain an element that does not exist in natural conditions. In 1938, German chemists Otto Hahn and Fritz Strassmann repeated in general terms the experience of the Joliot-Curie spouses, using uranium instead of aluminum. The results of the experiment were not at all what they expected - instead of a new superheavy element with a mass number greater than that of uranium, Hahn and Strassmann received light elements from the middle part of the periodic table: barium, krypton, bromine and some others. The experimenters themselves were unable to explain the observed phenomenon. Only the following year, physicist Lise Meitner, to whom Hahn reported his difficulties, found the correct explanation for the observed phenomenon, suggesting that when uranium is bombarded with neutrons, its nucleus splits (fissions). In this case, nuclei of lighter elements should have been formed (that’s where barium, krypton and other substances came from), as well as 2-3 free neutrons should have been released. Further research made it possible to clarify in detail the picture of what was happening.

Natural uranium consists of a mixture of three isotopes with masses 238, 234 and 235. The main amount of uranium is isotope-238, the nucleus of which includes 92 protons and 146 neutrons. Uranium-235 is only 1/140 of natural uranium (0.7% (it has 92 protons and 143 neutrons in its nucleus), and uranium-234 (92 protons, 142 neutrons) is only 1/17500 of the total mass of uranium (0 , 006%. The least stable of these isotopes is uranium-235.

From time to time, the nuclei of its atoms spontaneously divide into parts, as a result of which lighter elements of the periodic table are formed. The process is accompanied by the release of two or three free neutrons, which rush at enormous speed - about 10 thousand km/s (they are called fast neutrons). These neutrons can hit other uranium nuclei, causing nuclear reactions. Each isotope behaves differently in this case. Uranium-238 nuclei in most cases simply capture these neutrons without any further transformations. But in approximately one case out of five, when a fast neutron collides with the nucleus of the isotope-238, a curious nuclear reaction occurs: one of the neutrons of uranium-238 emits an electron, turning into a proton, that is, the uranium isotope turns into a more
heavy element - neptunium-239 (93 protons + 146 neutrons). But neptunium is unstable - after a few minutes, one of its neutrons emits an electron, turning into a proton, after which the neptunium isotope turns into the next element in the periodic table - plutonium-239 (94 protons + 145 neutrons). If a neutron hits the nucleus of unstable uranium-235, then fission immediately occurs - the atoms disintegrate with the emission of two or three neutrons. It is clear that in natural uranium, most of the atoms of which belong to the isotope-238, this reaction has no visible consequences - all free neutrons will eventually be absorbed by this isotope.

Well, what if we imagine a fairly massive piece of uranium consisting entirely of isotope-235?

Here the process will go differently: neutrons released during the fission of several nuclei, in turn, hitting neighboring nuclei, cause their fission. As a result, a new portion of neutrons is released, which splits the next nuclei. Under favorable conditions, this reaction proceeds like an avalanche and is called a chain reaction. To start it, a few bombarding particles may be enough.

Indeed, let uranium-235 be bombarded by only 100 neutrons. They will separate 100 uranium nuclei. In this case, 250 new neutrons of the second generation will be released (on average 2.5 per fission). Second generation neutrons will produce 250 fissions, which will release 625 neutrons. In the next generation it will become 1562, then 3906, then 9670, etc. The number of divisions will increase indefinitely if the process is not stopped.

However, in reality only a small fraction of neutrons reach the nuclei of atoms. The rest, quickly rushing between them, are carried away into the surrounding space. A self-sustaining chain reaction can only occur in a sufficiently large array of uranium-235, which is said to have a critical mass. (This mass under normal conditions is 50 kg.) It is important to note that the fission of each nucleus is accompanied by the release of a huge amount of energy, which turns out to be approximately 300 million times more than the energy spent on fission! (It is estimated that the complete fission of 1 kg of uranium-235 releases the same amount of heat as the combustion of 3 thousand tons of coal.)

This colossal burst of energy, released in a matter of moments, manifests itself as an explosion of monstrous force and underlies the action of nuclear weapons. But in order for this weapon to become a reality, it is necessary that the charge consist not of natural uranium, but of a rare isotope - 235 (such uranium is called enriched). It was later discovered that pure plutonium is also a fissile material and could be used in an atomic charge instead of uranium-235.

All these important discoveries were made on the eve of World War II. Soon, secret work on creating an atomic bomb began in Germany and other countries. In the USA, this problem was addressed in 1941. The entire complex of works was given the name “Manhattan Project”.

Administrative management of the project was carried out by General Groves, and scientific management was carried out by University of California professor Robert Oppenheimer. Both were well aware of the enormous complexity of the task facing them. Therefore, Oppenheimer's first concern was recruiting a highly intelligent scientific team. In the USA at that time there were many physicists who emigrated from Nazi Germany. It was not easy to attract them to create weapons directed against their former homeland. Oppenheimer spoke personally to everyone, using all the power of his charm. Soon he managed to gather a small group of theorists, whom he jokingly called “luminaries.” And in fact, it included the greatest specialists of that time in the field of physics and chemistry. (Among them are 13 Nobel Prize laureates, including Bohr, Fermi, Frank, Chadwick, Lawrence.) Besides them, there were many other specialists of various profiles.

The US government did not skimp on expenses, and the work took on a grand scale from the very beginning. In 1942, the world's largest research laboratory was founded at Los Alamos. The population of this scientific city soon reached 9 thousand people. In terms of the composition of scientists, the scope of scientific experiments, and the number of specialists and workers involved in the work, the Los Alamos Laboratory had no equal in world history. The Manhattan Project had its own police, counterintelligence, communications system, warehouses, villages, factories, laboratories, and its own colossal budget.

The main goal of the project was to obtain enough fissile material from which several atomic bombs could be created. In addition to uranium-235, as already mentioned, it could serve as a charge for a bomb. artificial element plutonium-239, that is, the bomb could be either uranium or plutonium.

Groves And Oppenheimer agreed that work should be carried out simultaneously in two directions, since it is impossible to decide in advance which of them will be more promising. Both methods were fundamentally different from each other: the accumulation of uranium-235 had to be carried out by separating it from the bulk of natural uranium, and plutonium could only be obtained as a result of a controlled nuclear reaction when uranium-238 was irradiated with neutrons. Both paths seemed unusually difficult and did not promise easy solutions.

In fact, how can one separate two isotopes that differ only slightly in weight and chemically behave in exactly the same way? Neither science nor technology has ever faced such a problem. The production of plutonium also seemed very problematic at first. Before this, the entire experience of nuclear transformations was reduced to a few laboratory experiments. Now it was necessary to master the production of kilograms of plutonium on an industrial scale, develop and create a special installation for this - a nuclear reactor, and learn to control the course of the nuclear reaction.

Both here and here a whole complex had to be resolved complex tasks. Therefore, the Manhattan Project consisted of several subprojects, headed by prominent scientists. Oppenheimer himself was the head of the Los Alamos Scientific Laboratory. Lawrence was in charge of the Radiation Laboratory at the University of California. Fermi conducted research at the University of Chicago to create a nuclear reactor.

At first, the most important problem was obtaining uranium. Before the war, this metal had virtually no use. Now that it was needed immediately in huge quantities, it turned out that there was no industrial method of producing it.

The Westinghouse company took up its development and quickly achieved success. After purifying the uranium resin (uranium occurs in nature in this form) and obtaining uranium oxide, it was converted into tetrafluoride (UF4), from which uranium metal was separated by electrolysis. If at the end of 1941 American scientists had only a few grams of uranium metal at their disposal, then already in November 1942 its industrial production at Westinghouse factories reached 6,000 pounds per month.

At the same time, work was underway to create a nuclear reactor. The process of producing plutonium actually boiled down to irradiating uranium rods with neutrons, as a result of which part of the uranium-238 would turn into plutonium. The sources of neutrons in this case could be fissile atoms of uranium-235, scattered in sufficient quantities among atoms of uranium-238. But in order to maintain the constant production of neutrons, a chain reaction of fission of uranium-235 atoms had to begin. Meanwhile, as already mentioned, for every atom of uranium-235 there were 140 atoms of uranium-238. It is clear that neutrons scattering in all directions had a much higher probability of meeting them on their way. That is, a huge number of released neutrons turned out to be absorbed by the main isotope without any benefit. Obviously, under such conditions a chain reaction could not take place. How to be?

At first it seemed that without the separation of two isotopes, the operation of the reactor was generally impossible, but one important circumstance was soon established: it turned out that uranium-235 and uranium-238 were susceptible to neutrons of different energies. The nucleus of a uranium-235 atom can be split by a neutron of relatively low energy, having a speed of about 22 m/s. Such slow neutrons are not captured by uranium-238 nuclei - for this they must have a speed of the order of hundreds of thousands of meters per second. In other words, uranium-238 is powerless to prevent the beginning and progress of a chain reaction in uranium-235 caused by neutrons slowed down to extremely low speeds - no more than 22 m/s. This phenomenon was discovered by the Italian physicist Fermi, who lived in the USA since 1938 and led the work here to create the first reactor. Fermi decided to use graphite as a neutron moderator. According to his calculations, the neutrons emitted from uranium-235, having passed through a 40 cm layer of graphite, should have reduced their speed to 22 m/s and begun a self-sustaining chain reaction in uranium-235.

Another moderator could be so-called “heavy” water. Since the hydrogen atoms included in it are very similar in size and mass to neutrons, they could best slow them down. (With fast neutrons, approximately the same thing happens as with balls: if a small ball hits a large one, it rolls back, almost without losing speed, but when it meets a small ball, it transfers a significant part of its energy to it - just like a neutron in an elastic collision bounces off a heavy nucleus, slowing down only slightly, and when colliding with the nuclei of hydrogen atoms, it very quickly loses all its energy.) However, ordinary water is not suitable for slowing down, since its hydrogen tends to absorb neutrons. That is why deuterium, which is part of “heavy” water, should be used for this purpose.

In early 1942, under Fermi's leadership, construction began on the first nuclear reactor in history in the tennis court area under the west stands of Chicago Stadium. The scientists carried out all the work themselves. The reaction can be controlled in the only way - by adjusting the number of neutrons participating in the chain reaction. Fermi intended to achieve this using rods made of substances such as boron and cadmium, which strongly absorb neutrons. The moderator was graphite bricks, from which the physicists built columns 3 m high and 1.2 m wide. Rectangular blocks with uranium oxide were installed between them. The entire structure required about 46 tons of uranium oxide and 385 tons of graphite. To slow down the reaction, rods of cadmium and boron were introduced into the reactor.

If this were not enough, then for insurance, two scientists stood on a platform located above the reactor with buckets filled with a solution of cadmium salts - they were supposed to pour them onto the reactor if the reaction got out of control. Fortunately, this was not necessary. On December 2, 1942, Fermi ordered all control rods to be extended and the experiment began. After four minutes, the neutron counters began to click louder and louder. With every minute the intensity of the neutron flux became greater. This indicated that a chain reaction was taking place in the reactor. It lasted for 28 minutes. Then Fermi gave the signal, and the lowered rods stopped the process. Thus, for the first time, man freed the energy of the atomic nucleus and proved that he could control it at will. Now there was no longer any doubt that nuclear weapons were a reality.

In 1943, the Fermi reactor was dismantled and transported to the Aragonese National Laboratory (50 km from Chicago). Another nuclear reactor was soon built here, using heavy water as a moderator. It consisted of a cylindrical aluminum tank containing 6.5 tons of heavy water, into which were vertically immersed 120 rods of uranium metal, encased in an aluminum shell. The seven control rods were made of cadmium. Around the tank there was a graphite reflector, then a screen made of lead and cadmium alloys. The entire structure was enclosed in a concrete shell with a wall thickness of about 2.5 m.

Experiments at these pilot reactors confirmed the possibility industrial production plutonium

The main center of the Manhattan Project soon became the town of Oak Ridge in the Tennessee River Valley, whose population grew to 79 thousand people in a few months. Here, the first enriched uranium production plant in history was built in a short time. An industrial reactor producing plutonium was launched here in 1943. In February 1944, about 300 kg of uranium was extracted from it daily, from the surface of which plutonium was obtained by chemical separation. (To do this, the plutonium was first dissolved and then precipitated.) The purified uranium was then returned to the reactor. That same year, construction began on the huge Hanford plant in the barren, bleak desert on the south bank of the Columbia River. Three powerful nuclear reactors were located here, producing several hundred grams of plutonium every day.

In parallel, research was in full swing to develop an industrial process for uranium enrichment.

After considering various options, Groves and Oppenheimer decided to focus their efforts on two methods: gaseous diffusion and electromagnetic.

The gas diffusion method was based on a principle known as Graham's law (it was first formulated in 1829 by the Scottish chemist Thomas Graham and developed in 1896 by the English physicist Reilly). According to this law, if two gases, one of which is lighter than the other, are passed through a filter with negligibly small holes, then slightly more of the light gas will pass through it than of the heavy one. In November 1942, Urey and Dunning from Columbia University created a gaseous diffusion method for separating uranium isotopes based on the Reilly method.

Since natural uranium is a solid, it was first converted into uranium fluoride (UF6). This gas was then passed through microscopic - on the order of thousandths of a millimeter - holes in the filter partition.

Since the difference in the molar weights of the gases was very small, behind the partition the content of uranium-235 increased by only 1.0002 times.

In order to increase the amount of uranium-235 even more, the resulting mixture is again passed through a partition, and the amount of uranium is again increased by 1.0002 times. Thus, to increase the uranium-235 content to 99%, it was necessary to pass the gas through 4000 filters. This took place at a huge gaseous diffusion plant in Oak Ridge.

In 1940, under the leadership of Ernest Lawrence, research began on the separation of uranium isotopes by the electromagnetic method at the University of California. It was necessary to find physical processes that would allow isotopes to be separated using the difference in their masses. Lawrence attempted to separate isotopes using the principle of a mass spectrograph, an instrument used to determine the masses of atoms.

The principle of its operation was as follows: pre-ionized atoms were accelerated by an electric field and then passed through a magnetic field, in which they described circles located in a plane perpendicular to the direction of the field. Since the radii of these trajectories were proportional to the mass, light ions ended up on circles of smaller radius than heavy ones. If traps were placed along the path of the atoms, then different isotopes could be collected separately in this way.

That was the method. In laboratory conditions it gave good results. But building a facility where isotope separation could be carried out on an industrial scale proved extremely difficult. However, Lawrence eventually managed to overcome all difficulties. The result of his efforts was the appearance of calutron, which was installed in a giant plant in Oak Ridge.

This electromagnetic plant was built in 1943 and turned out to be perhaps the most expensive brainchild of the Manhattan Project. Lawrence's method required a large number of complex, not yet developed devices involving high voltage, high vacuum and strong magnetic fields. The scale of the costs turned out to be enormous. Calutron had a giant electromagnet, the length of which reached 75 m and weighed about 4000 tons.

Several thousand tons of silver wire were used for the windings for this electromagnet.

The entire work (not counting the cost of $300 million in silver, which the State Treasury provided only temporarily) cost $400 million. The Ministry of Defense paid 10 million for the electricity consumed by calutron alone. Most of The equipment of the Oak Ridge plant surpassed in scale and precision of manufacture everything that had ever been developed in this field of technology.

But all these costs were not in vain. Having spent a total of about 2 billion dollars, US scientists by 1944 created a unique technology for uranium enrichment and plutonium production. Meanwhile, at the Los Alamos laboratory they were working on the design of the bomb itself. The principle of its operation was in general terms clear for a long time: the fissile substance (plutonium or uranium-235) had to be transferred to a critical state at the moment of explosion (for a chain reaction to occur, the charge mass should be even noticeably greater than the critical one) and irradiated with a neutron beam, which entailed is the beginning of a chain reaction.

According to calculations, the critical mass of the charge exceeded 50 kilograms, but they were able to significantly reduce it. In general, the value of the critical mass is strongly influenced by several factors. The larger the surface area of ​​the charge, the more neutrons are uselessly emitted into the surrounding space. A sphere has the smallest surface area. Consequently, spherical charges, other things being equal, have the smallest critical mass. In addition, the value of the critical mass depends on the purity and type of fissile materials. It is inversely proportional to the square of the density of this material, which allows, for example, by doubling the density, reducing the critical mass by four times. The required degree of subcriticality can be obtained, for example, by compacting fissile material due to the explosion of a conventional charge explosive, made in the form of a spherical shell surrounding a nuclear charge. The critical mass can also be reduced by surrounding the charge with a screen that reflects neutrons well. Lead, beryllium, tungsten, natural uranium, iron and many others can be used as such a screen.

One possible design of an atomic bomb consists of two pieces of uranium, which, when combined, form a mass greater than critical. In order to cause a bomb explosion, you need to bring them closer together as quickly as possible. The second method is based on the use of an inward-converging explosion. In this case, a stream of gases from a conventional explosive was directed at the fissile material located inside and compressed it until it reached a critical mass. Combining a charge and intensely irradiating it with neutrons, as already mentioned, causes a chain reaction, as a result of which in the first second the temperature increases to 1 million degrees. During this time, only about 5% of the critical mass managed to separate. The rest of the charge in early bomb designs evaporated without
any benefit.

The first atomic bomb in history (it was given the name Trinity) was assembled in the summer of 1945. And on June 16, 1945, the first atomic explosion on Earth was carried out at the nuclear test site in the Alamogordo desert (New Mexico). The bomb was placed in the center of the test site on top of a 30-meter steel tower. Around her on long distance recording equipment was located. There was an observation post 9 km away, and a command post 16 km away. The atomic explosion made a stunning impression on all witnesses to this event. According to eyewitnesses' descriptions, it felt as if many suns had united into one and illuminated the test site at once. Then a huge fireball appeared over the plain and a round cloud of dust and light began to rise towards it slowly and ominously.

Taking off from the ground, this fireball soared to a height of more than three kilometers in a few seconds. With every moment it grew in size, soon its diameter reached 1.5 km, and it slowly rose into the stratosphere. Then the fireball gave way to a column of billowing smoke, which stretched to a height of 12 km, taking the shape of a giant mushroom. All this was accompanied by a terrible roar, from which the earth shook. The power of the exploding bomb exceeded all expectations.

As soon as the radiation situation allowed, several Sherman tanks, lined with lead plates on the inside, rushed to the area of ​​the explosion. On one of them was Fermi, who was eager to see the results of his work. What appeared before his eyes was a dead, scorched earth, on which all living things had been destroyed within a radius of 1.5 km. The sand had baked into a glassy greenish crust that covered the ground. In a huge crater lay the mangled remains of a steel support tower. The force of the explosion was estimated at 20,000 tons of TNT.

The next step was to be the combat use of the atomic bomb against Japan, which, after the surrender of Nazi Germany, alone continued the war with the United States and its allies. There were no launch vehicles at that time, so the bombing had to be carried out from an airplane. The components of the two bombs were transported with great care by the cruiser Indianapolis to the island of Tinian, where the 509th Combined Air Force Group was based. These bombs differed somewhat from each other in the type of charge and design.

The first atomic bomb - "Baby" - was a large-sized aerial bomb with an atomic charge made of highly enriched uranium-235. Its length was about 3 m, diameter - 62 cm, weight - 4.1 tons.

The second atomic bomb - "Fat Man" - with a charge of plutonium-239 was egg-shaped with a large stabilizer. Its length
was 3.2 m, diameter 1.5 m, weight - 4.5 tons.

On August 6, Colonel Tibbets' B-29 Enola Gay bomber dropped "Little Boy" on the major Japanese city of Hiroshima. The bomb was lowered by parachute and exploded, as planned, at an altitude of 600 m from the ground.

The consequences of the explosion were terrible. Even for the pilots themselves, the sight of a peaceful city destroyed by them in an instant made a depressing impression. Later, one of them admitted that at that second they saw the worst thing a person can see.

For those who were on earth, what was happening resembled true hell. First of all, a heat wave passed over Hiroshima. Its effect lasted only a few moments, but was so powerful that it melted even tiles and quartz crystals in granite slabs, turned telephone poles at a distance of 4 km into coal and, finally, incinerated human bodies so much that only shadows remained from them on the asphalt of the pavements or on the walls of houses. Then a monstrous gust of wind burst out from under the fireball and rushed over the city at a speed of 800 km/h, destroying everything in its path. Houses that could not withstand his furious onslaught collapsed as if knocked down. There is not a single intact building left in the giant circle with a diameter of 4 km. A few minutes after the explosion, black radioactive rain fell over the city - this moisture turned into steam condensed in the high layers of the atmosphere and fell to the ground in the form of large drops mixed with radioactive dust.

After the rain, a new gust of wind hit the city, this time blowing in the direction of the epicenter. It was weaker than the first, but still strong enough to uproot trees. The wind fanned a gigantic fire in which everything that could burn burned. Of the 76 thousand buildings, 55 thousand were completely destroyed and burned. Witnesses of this terrible catastrophe recalled torch-men, from whom burnt clothes fell to the ground along with rags of skin, and of crowds of maddened people, covered with terrible burns, rushing screaming through the streets. There was a suffocating stench of burnt human flesh in the air. There were people lying everywhere, dead and dying. There were many who were blind and deaf and, poking in all directions, could not make out anything in the chaos that reigned around them.

The unfortunate people, who were located at a distance of up to 800 m from the epicenter, literally burned out in a split second - their insides evaporated and their bodies turned into lumps of smoking coals. Those located 1 km from the epicenter were affected by radiation sickness in an extremely severe form. Within a few hours, they began to vomit violently, their temperature jumped to 39-40 degrees, and they began to experience shortness of breath and bleeding. Then non-healing ulcers appeared on the skin, the composition of the blood changed dramatically, and hair fell out. After terrible suffering, usually on the second or third day, death occurred.

In total, about 240 thousand people died from the explosion and radiation sickness. About 160 thousand received radiation sickness in a milder form - their painful death was delayed by several months or years. When news of the disaster spread throughout the country, all of Japan was paralyzed with fear. It increased further after Major Sweeney's Box Car dropped a second bomb on Nagasaki on August 9. Several hundred thousand inhabitants were also killed and injured here. Unable to resist the new weapons, the Japanese government capitulated - the atomic bomb ended World War II.

War is over. It lasted only six years, but managed to change the world and people almost beyond recognition.

Human civilization before 1939 and human civilization after 1945 are strikingly different from each other. There are many reasons for this, but one of the most important is the emergence of nuclear weapons. It can be said without exaggeration that the shadow of Hiroshima lies over the entire second half of the 20th century. It became a deep moral burn for many millions of people, both contemporaries of this catastrophe and those born decades after it. Modern man can no longer think about the world the way they thought about it before August 6, 1945 - he understands too clearly that this world can turn into nothing in a few moments.

Modern man cannot look at war the way his grandfathers and great-grandfathers did - he knows for sure that this war will be the last, and there will be neither winners nor losers in it. Nuclear weapons have left their mark on all areas public life, and modern civilization cannot live by the same laws as sixty or eighty years ago. No one understood this better than the creators of the atomic bomb themselves.

"People of our planet , wrote Robert Oppenheimer, must unite. The horror and destruction sown by the last war dictate this thought to us. The explosions of atomic bombs proved it with all cruelty. Other people at other times have already said similar words - only about other weapons and about other wars. They weren't successful. But anyone who today would say that these words are useless is misled by the vicissitudes of history. We cannot be convinced of this. The results of our work leave humanity no choice but to create a united world. A world based on legality and humanity."

An atomic bomb is a projectile designed to produce a high-power explosion as a result of a very rapid release of nuclear (atomic) energy.

The principle of operation of atomic bombs

The nuclear charge is divided into several parts to critical sizes so that in each of them a self-developing uncontrolled chain reaction of fission of atoms of the fissile substance cannot begin. Such a reaction will occur only when all parts of the charge are quickly connected into one whole. The completeness of the reaction and, ultimately, the power of the explosion greatly depends on the speed of convergence of the individual parts. To impart high speed to parts of the charge, an explosion of a conventional explosive can be used. If parts of a nuclear charge are placed in radial directions at a certain distance from the center, and with outside place TNT charges, then it is possible to carry out an explosion of conventional charges directed towards the center of the nuclear charge. All parts of the nuclear charge will not only combine into a single whole with enormous speed, but will also find themselves for some time compressed on all sides by the enormous pressure of the explosion products and will not be able to separate immediately as soon as a nuclear chain reaction begins in the charge. As a result of this, significantly greater fission will occur than without such compression, and, consequently, the power of the explosion will increase. A neutron reflector also contributes to an increase in the explosion power for the same amount of fissile material (the most effective reflectors are beryllium< Be >, graphite, heavy water< H3O >). The first fission, which would start a chain reaction, requires at least one neutron. It is impossible to count on the timely start of a chain reaction under the influence of neutrons appearing during the spontaneous fission of nuclei, because it occurs relatively rarely: for U-235 - 1 decay per hour per 1 g. substances. There are also very few neutrons existing in free form in the atmosphere: through S = 1 cm/sq. On average, about 6 neutrons fly by per second. For this reason, an artificial source of neutrons is used in a nuclear charge - a kind of nuclear detonator capsule. It also ensures that many fissions begin simultaneously, so the reaction proceeds in the form of a nuclear explosion.

Detonation options (Gun and implosion schemes)

There are two main schemes for detonating a fissile charge: cannon, otherwise called ballistic, and implosive.

The "cannon design" was used in some first generation nuclear weapons. The essence of the cannon circuit is to shoot a charge of gunpowder from one block of fissile material of subcritical mass (“bullet”) into another stationary one (“target”). The blocks are designed so that when connected, their total mass becomes supercritical.

This detonation method is possible only in uranium ammunition, since plutonium has a two orders of magnitude higher neutron background, which sharply increases the likelihood of premature development of a chain reaction before the blocks are connected. This leads to an incomplete release of energy (the so-called “fizzy”, English). To implement the cannon circuit in plutonium ammunition, it is necessary to increase the speed of connection of the charge parts to a technically unattainable level. In addition, uranium withstands mechanical overloads better than plutonium.

Implosive scheme. This detonation scheme involves achieving a supercritical state by compressing the fissile material with a focused shock wave created by the explosion of a chemical explosive. To focus the shock wave, so-called explosive lenses are used, and the detonation is carried out simultaneously at many points with precision accuracy. The creation of such a system for the placement of explosives and detonation was at one time one of the most difficult tasks. The formation of a converging shock wave was ensured by the use of explosive lenses from “fast” and “slow” explosives - TATV (Triaminotrinitrobenzene) and baratol (a mixture of trinitrotoluene with barium nitrate), and some additives)

North Korea threatens the US with testing a super-powerful hydrogen bomb in the Pacific Ocean. Japan, which may suffer as a result of the tests, called North Korea's plans completely unacceptable. Presidents Donald Trump and Kim Jong-un argue in interviews and talk about open military conflict. For those who do not understand nuclear weapons, but want to be in the know, The Futurist has compiled a guide.

How do nuclear weapons work?

Like a regular stick of dynamite, a nuclear bomb uses energy. Only it is not released during the primitive chemical reaction, but in complex nuclear processes. There are two main ways to extract nuclear energy from an atom. IN nuclear fission the nucleus of an atom decays into two smaller fragments with a neutron. Nuclear fusion – the process by which the Sun produces energy – involves the joining of two smaller atoms to form a larger one. In any process, fission or fusion, large amounts of thermal energy and radiation are released. Depending on whether nuclear fission or fusion is used, bombs are divided into nuclear (atomic) And thermonuclear .

Can you tell me more about nuclear fission?

Atomic bomb explosion over Hiroshima (1945)

As you remember, an atom is made up of three types of subatomic particles: protons, neutrons and electrons. The center of the atom, called core , consists of protons and neutrons. Protons are positively charged, electrons are negatively charged, and neutrons have no charge at all. The proton-electron ratio is always one to one, so the atom as a whole has a neutral charge. For example, a carbon atom has six protons and six electrons. Particles are held together by a fundamental force - strong nuclear force .

The properties of an atom can change significantly depending on how many different particles it contains. If you change the number of protons, you will have a different chemical element. If you change the number of neutrons, you get isotope the same element that you have in your hands. For example, carbon has three isotopes: 1) carbon-12 (six protons + six neutrons), which is a stable and common form of the element, 2) carbon-13 (six protons + seven neutrons), which is stable but rare, and 3) carbon -14 (six protons + eight neutrons), which is rare and unstable (or radioactive).

Most atomic nuclei are stable, but some are unstable (radioactive). These nuclei spontaneously emit particles that scientists call radiation. This process is called radioactive decay . There are three types of decay:

Alpha decay : The nucleus emits an alpha particle - two protons and two neutrons bound together. Beta decay : A neutron turns into a proton, electron and antineutrino. The ejected electron is a beta particle. Spontaneous fission: the nucleus disintegrates into several parts and emits neutrons, and also emits a pulse of electromagnetic energy - a gamma ray. It is the latter type of decay that is used in a nuclear bomb. Free neutrons emitted as a result of fission begin chain reaction , which releases a colossal amount of energy.

What are nuclear bombs made of?

They can be made from uranium-235 and plutonium-239. Uranium occurs in nature as a mixture of three isotopes: 238 U (99.2745% of natural uranium), 235 U (0.72%) and 234 U (0.0055%). The most common 238 U does not support a chain reaction: only 235 U is capable of this. To achieve maximum explosion power, it is necessary that the content of 235 U in the “filling” of the bomb is at least 80%. Therefore, uranium is produced artificially enrich . To do this, the mixture of uranium isotopes is divided into two parts so that one of them contains more than 235 U.

Typically, isotope separation leaves behind a lot of depleted uranium that is unable to undergo a chain reaction—but there is a way to make it do so. The fact is that plutonium-239 does not occur in nature. But it can be obtained by bombarding 238 U with neutrons.

How is their power measured?

​The power of a nuclear and thermonuclear charge is measured in TNT equivalent - the amount of trinitrotoluene that must be detonated to obtain a similar result. It is measured in kilotons (kt) and megatons (Mt). The yield of ultra-small nuclear weapons is less than 1 kt, while super-powerful bombs yield more than 1 mt.

The power of the Soviet “Tsar Bomb” was, according to various sources, from 57 to 58.6 megatons in TNT equivalent; the power of the thermonuclear bomb, which the DPRK tested in early September, was about 100 kilotons.

Who created nuclear weapons?

American physicist Robert Oppenheimer and General Leslie Groves

In the 1930s, Italian physicist Enrico Fermi demonstrated that elements bombarded by neutrons could be transformed into new elements. The result of this work was the discovery slow neutrons , as well as the discovery of new elements not presented on periodic table. Soon after Fermi's discovery, German scientists Otto Hahn And Fritz Strassmann bombarded uranium with neutrons, resulting in the formation of a radioactive isotope of barium. They concluded that low-speed neutrons cause the uranium nucleus to break into two smaller pieces.

This work excited the minds of the whole world. At Princeton University Niels Bohr worked with John Wheeler to develop a hypothetical model of the fission process. They suggested that uranium-235 undergoes fission. Around the same time, other scientists discovered that the process of fission led to the formation of more more neutrons. This prompted Bohr and Wheeler to ask important question: Could the free neutrons created by fission start a chain reaction that would release enormous amounts of energy? If this is so, then it is possible to create weapons of unimaginable power. Their assumptions were confirmed by a French physicist Frederic Joliot-Curie . His conclusion became the impetus for developments in the creation of nuclear weapons.

Physicists from Germany, England, the USA, and Japan worked on the creation of atomic weapons. Before the start of World War II Albert Einstein wrote to the US President Franklin Roosevelt that Nazi Germany plans to purify uranium-235 and create an atomic bomb. It now turns out that Germany was far from carrying out a chain reaction: they were working on a “dirty”, highly radioactive bomb. Be that as it may, the US government threw all its efforts into creating an atomic bomb in as soon as possible. The Manhattan Project was launched, led by an American physicist Robert Oppenheimer and general Leslie Groves . It was attended by prominent scientists who emigrated from Europe. By the summer of 1945, atomic weapons were created based on two types of fissile material - uranium-235 and plutonium-239. One bomb, the plutonium “Thing,” was detonated during testing, and two more, the uranium “Baby” and the plutonium “Fat Man,” were dropped on the Japanese cities of Hiroshima and Nagasaki.

How does a thermonuclear bomb work and who invented it?

Thermonuclear bomb is based on the reaction nuclear fusion . Unlike nuclear fission, which can occur either spontaneously or forcedly, nuclear fusion is impossible without the supply of external energy. Atomic nuclei are positively charged - so they repel each other. This situation is called the Coulomb barrier. To overcome repulsion, these particles must be accelerated to crazy speeds. This can be done at very high temperatures - on the order of several million Kelvin (hence the name). There are three types of thermonuclear reactions: self-sustaining (take place in the depths of stars), controlled and uncontrolled or explosive - they are used in hydrogen bombs.

The idea of ​​a bomb with thermonuclear fusion initiated by an atomic charge was proposed by Enrico Fermi to his colleague Edward Teller back in 1941, at the very beginning of the Manhattan Project. However, this idea was not in demand at that time. Teller's developments were improved Stanislav Ulam , making the idea of ​​a thermonuclear bomb feasible in practice. In 1952, the first thermonuclear explosive device was tested on Enewetak Atoll during Operation Ivy Mike. However, it was a laboratory sample, unsuitable for combat. A year later, the Soviet Union detonated the world's first thermonuclear bomb, assembled according to the design of physicists Andrey Sakharov And Yulia Kharitona . The device resembled a layer cake, so the formidable weapon was nicknamed “Puff”. In the course of further development, the most powerful bomb on Earth, the “Tsar Bomba” or “Kuzka’s Mother,” was born. In October 1961, it was tested on the Novaya Zemlya archipelago.

What are thermonuclear bombs made of?

If you thought that hydrogen and thermonuclear bombs are different things, you were wrong. These words are synonymous. It is hydrogen (or rather, its isotopes - deuterium and tritium) that is required to carry out a thermonuclear reaction. However, there is a difficulty: in order to detonate a hydrogen bomb, it is first necessary to obtain a high temperature during a conventional nuclear explosion - only then will the atomic nuclei begin to react. Therefore, in the case of a thermonuclear bomb, design plays a big role.

Two schemes are widely known. The first is Sakharov’s “puff pastry”. In the center was a nuclear detonator, which was surrounded by layers of lithium deuteride mixed with tritium, which were interspersed with layers of enriched uranium. This design made it possible to achieve a power within 1 Mt. The second is the American Teller-Ulam scheme, where the nuclear bomb and hydrogen isotopes were located separately. It looked like this: below there was a container with a mixture of liquid deuterium and tritium, in the center of which there was a “spark plug” - a plutonium rod, and on top - a conventional nuclear charge, and all this in a shell of heavy metal (for example, depleted uranium). Fast neutrons produced during the explosion cause atomic fission reactions in the uranium shell and add energy to the total energy of the explosion. Adding additional layers of lithium uranium-238 deuteride makes it possible to create projectiles of unlimited power. In 1953, Soviet physicist Victor Davidenko accidentally repeated the Teller-Ulam idea, and on its basis Sakharov came up with a multi-stage scheme that made it possible to create weapons of unprecedented power. “Kuzka’s Mother” worked exactly according to this scheme.

What other bombs are there?

There are also neutron ones, but this is generally scary. Essentially, a neutron bomb is a low-power thermonuclear bomb, 80% of the explosion energy of which is radiation (neutron radiation). It looks like a regular nuclear weapon low power, to which a block with a beryllium isotope is added - a source of neutrons. When a nuclear charge explodes, a thermonuclear reaction is triggered. This type of weapon was developed by an American physicist Samuel Cohen . It was believed that neutron weapons destroy all living things even in shelters, but the range of destruction of such weapons is small, since the atmosphere disperses streams of fast neutrons, and the shock wave long distances turns out to be stronger.

What about the cobalt bomb?

No, son, this is fantastic. Officially, no country has cobalt bombs. Theoretically, this is a thermonuclear bomb with a cobalt shell, which ensures strong radioactive contamination of the area even with a relatively weak nuclear explosion. 510 tons of cobalt can infect the entire surface of the Earth and destroy all life on the planet. Physicist Leo Szilard , who described this hypothetical design in 1950, called it the "Doomsday Machine".

What's cooler: a nuclear bomb or a thermonuclear one?

Full-scale model of "Tsar Bomba"

The hydrogen bomb is much more advanced and technologically advanced than the atomic one. Its explosive power far exceeds that of an atomic one and is limited only by the number of available components. In a thermonuclear reaction, much more energy is released for each nucleon (the so-called constituent nuclei, protons and neutrons) than in a nuclear reaction. For example, the fission of a uranium nucleus produces 0.9 MeV (megaelectronvolt) per nucleon, and the fusion of a helium nucleus from hydrogen nuclei releases an energy of 6 MeV.

Like bombs deliverto the goal?

At first they were dropped from airplanes, but air defense systems were constantly improving, and delivering nuclear weapons in this way turned out to be unwise. With increasing production rocket technology all rights to deliver nuclear weapons were transferred to ballistic and cruise missiles of various bases. Therefore, a bomb now means not a bomb, but a warhead.

It is believed that the North Korean hydrogen bomb is too large to be mounted on a rocket - so if the DPRK decides to carry out the threat, it will be carried by ship to the explosion site.

What are the consequences of a nuclear war?

Hiroshima and Nagasaki are only a small part of the possible apocalypse. ​For example, the “nuclear winter” hypothesis is known, which was put forward by the American astrophysicist Carl Sagan and the Soviet geophysicist Georgy Golitsyn. It is assumed that the explosion of several nuclear warheads (not in the desert or water, but in populated areas) will cause many fires, and a large amount of smoke and soot will spill into the atmosphere, which will lead to global cooling. The hypothesis has been criticized by comparing the effect to volcanic activity, which has little effect on climate. In addition, some scientists note that global warming is more likely to occur than cooling - although both sides hope that we will never know.

Are nuclear weapons allowed?

After the arms race in the 20th century, countries came to their senses and decided to limit the use of nuclear weapons. The UN adopted treaties on the non-proliferation of nuclear weapons and the ban on nuclear tests (the latter was not signed by the young nuclear powers India, Pakistan, and the DPRK). In July 2017, a new treaty on the prohibition of nuclear weapons was adopted.

“Each State Party undertakes never under any circumstances to develop, test, produce, manufacture, otherwise acquire, possess or stockpile nuclear weapons or other nuclear explosive devices,” states the first article of the treaty. .

However, the document will not come into force until 50 states ratify it.

As is known, to first generation nuclear weapons, it is often called ATOMIC, refers to warheads based on the use of fission energy of uranium-235 or plutonium-239 nuclei. The first ever test of such a 15 kt charger was carried out in the United States on July 16, 1945 at the Alamogordo test site.

The explosion of the first Soviet atomic bomb in August 1949 gave new impetus to the development of work on the creation second generation nuclear weapons. It is based on the technology of using the energy of thermonuclear reactions for the synthesis of nuclei of heavy hydrogen isotopes - deuterium and tritium. Such weapons are called thermonuclear or hydrogen. The first test of the Mike thermonuclear device was carried out by the United States on November 1, 1952 on the island of Elugelab (Marshall Islands), the yield of which was 5-8 million tons. The following year, a thermonuclear charge was detonated in the USSR.

The implementation of atomic and thermonuclear reactions has opened up wide opportunities for their use in the creation of a series of various ammunition of subsequent generations. Towards third generation nuclear weapons include special charges (ammunition), in which, due to a special design, a redistribution of the explosion energy is achieved in favor of one of the damaging factors. Other versions of the charges of such weapons ensure the creation of a focus of one or another damaging factor in a certain direction, which also leads to a significant increase in its damaging effect.

An analysis of the history of the creation and improvement of nuclear weapons indicates that the United States has invariably taken the lead in the creation of new models. However, some time passed and the USSR eliminated these unilateral advantages of the United States. Third generation nuclear weapons are no exception in this regard. One of the most famous examples of third generation nuclear weapons is NEUTRON weapons.

What are neutron weapons?

Neutron weapons were widely discussed at the turn of the 60s. However, it later became known that the possibility of its creation had been discussed long before that. Ex-president World Federation of Scientists, professor from Great Britain E. Burop recalled that he first heard about this back in 1944, when he worked as part of a group of English scientists in the United States on the “Manhattan Project.” Work on the creation of neutron weapons was initiated by the need to obtain a powerful weapon with selective destruction capability for use directly on the battlefield.

The first explosion of a neutron charger (code number W-63) was carried out in an underground adit in Nevada in April 1963. The neutron flux obtained during testing turned out to be significantly lower than the calculated value, which significantly reduced the combat capabilities of the new weapon. It took almost another 15 years for neutron charges to acquire all the qualities of a military weapon. According to Professor E. Burop, the fundamental difference between the device of a neutron charge and a thermonuclear one is the different rate of energy release: “ In a neutron bomb, the release of energy occurs much more slowly. It's like a time squib«.

Due to this slowdown, the energy spent on the formation of the shock wave and light radiation decreases and, accordingly, its release in the form of a neutron flux increases. In the course of further work, certain successes were achieved in ensuring the focusing of neutron radiation, which made it possible not only to enhance its destructive effect in a certain direction, but also to reduce the danger when using it for one’s troops.

In November 1976, another test of a neutron warhead was carried out in Nevada, during which very impressive results were obtained. As a result, at the end of 1976, a decision was made to produce components for 203-mm caliber neutron projectiles and warheads for the Lance missile. Later, in August 1981, at a meeting of the Nuclear Planning Group of the US National Security Council, a decision was made on full-scale production of neutron weapons: 2000 shells for a 203-mm howitzer and 800 warheads for the Lance missile.

When a neutron warhead explodes, the main damage to living organisms is caused by a stream of fast neutrons. According to calculations, for every kiloton of charge power, about 10 neutrons are released, which propagate with enormous speed in the surrounding space. These neutrons have an extremely high damaging effect on living organisms, much stronger than even Y-radiation and shock waves. For comparison, we point out that with the explosion of a conventional nuclear charge with a power of 1 kiloton, openly located manpower will be destroyed by a shock wave at a distance of 500-600 m. With the explosion of a neutron warhead of the same power, the destruction of manpower will occur at a distance of approximately three times greater.

The neutrons produced during the explosion move at speeds of several tens of kilometers per second. Bursting like projectiles into living cells of the body, they knock out nuclei from atoms, break molecular bonds, and form free radicals that are highly reactive, which leads to disruption of the basic cycles of life processes.

As neutrons move through the air as a result of collisions with the nuclei of gas atoms, they gradually lose energy. This leads to at a distance of about 2 km their damaging effect practically ceases. In order to reduce the destructive effect of the accompanying shock wave, the power of the neutron charge is chosen in the range from 1 to 10 kt, and the height of the explosion above the ground is about 150-200 meters.

According to some American scientists, thermonuclear experiments are being conducted at the Los Alamos and Sandia laboratories in the United States and at the All-Russian Institute of Experimental Physics in Sarov (Arzamas-16), in which, along with research on obtaining electrical energy, the possibility of obtaining purely thermonuclear explosives is being studied. The most likely by-product of the ongoing research, in their opinion, could be an improvement in the energy-mass characteristics of nuclear warheads and the creation of a neutron mini-bomb. According to experts, such a neutron warhead with a TNT equivalent of just one ton can create a lethal dose of radiation at distances of 200-400 m.

Neutron weapons are a powerful defensive weapon and their most effective use is possible when repelling aggression, especially when the enemy has invaded the protected territory. Neutron munitions are tactical weapons and their use is most likely in so-called "limited" wars, primarily in Europe. These weapons may become especially important for Russia, since with the weakening of its armed forces and the increasing threat of regional conflicts, it will be forced to place greater emphasis on nuclear weapons in ensuring its security.

The use of neutron weapons can be especially effective when repelling a massive tank attack. It is known that tank armor at certain distances from the epicenter of the explosion (more than 300-400 m during the explosion of a nuclear charge with a power of 1 kt) provides protection for crews from the shock wave and Y-radiation. At the same time, fast neutrons penetrate steel armor without significant attenuation.

Calculations show that in the event of an explosion of a neutron charge with a power of 1 kiloton, tank crews will be instantly disabled within a radius of 300 m from the epicenter and die within two days. Crews located at a distance of 300-700 m will fail in a few minutes and will also die within 6-7 days; at distances of 700-1300 m they will be ineffective in a few hours, and the death of most of them will last for several weeks. At distances of 1300-1500 m, a certain part of the crews will get serious illnesses and gradually become incapacitated.

Neutron warheads can also be used in missile defense systems to combat the warheads of attacking missiles along the trajectory. According to experts' calculations, fast neutrons, having a high penetrating ability, will pass through the lining of enemy warheads and cause damage to their electronic equipment. In addition, neutrons interacting with the uranium or plutonium nuclei of an atomic warhead detonator will cause them to fission.

Such a reaction will occur with a large release of energy, which ultimately can lead to heating and destruction of the detonator. This, in turn, will cause the entire warhead charge to fail. This property of neutron weapons was used in US missile defense systems. Back in the mid-70s, neutron warheads were installed on Sprint interceptor missiles of the Safeguard system deployed around the Grand Forks airbase (North Dakota). It is possible that the future US national missile defense system will also use neutron warheads.

As is known, in accordance with the commitments announced by the presidents of the United States and Russia in September-October 1991, all nuclear artillery shells and warheads of ground-based tactical missiles must be eliminated. However, there is no doubt that if the military-political situation changes and a political decision is made, the proven technology of neutron warheads makes it possible to establish their mass production in a short time.

"Super EMP"

Shortly after the end of World War II, with a monopoly on nuclear weapons, the United States resumed testing to improve them and determine the damaging effects of a nuclear explosion. At the end of June 1946, nuclear explosions were carried out in the area of ​​Bikini Atoll (Marshall Islands) under the code “Operation Crossroads”, during which the damaging effects of atomic weapons were studied.

During these test explosions it was discovered new physical phenomenon — formation of a powerful pulse of electromagnetic radiation (EMR), to which great interest was immediately shown. EMP turned out to be especially significant during high explosions. In the summer of 1958, nuclear explosions were carried out at high altitudes. The first series, coded “Hardtack,” was conducted over the Pacific Ocean near Johnston Island. During the tests, two megaton-class charges were detonated: “Tek” - at an altitude of 77 kilometers and “Orange” - at an altitude of 43 kilometers.

In 1962, high-altitude explosions continued: at an altitude of 450 km, under the code “Starfish,” a warhead with a yield of 1.4 megatons was detonated. The Soviet Union also during 1961-1962. conducted a series of tests during which the impact of high-altitude explosions (180-300 km) on the functioning of missile defense system equipment was studied.
During these tests, powerful electromagnetic pulses were recorded, which had a great damaging effect on electronic equipment, communication and power lines, radio and radar stations over long distances. Since then, military experts have continued to pay great attention to research into the nature of this phenomenon, its damaging effects, and ways to protect their combat and support systems from it.

The physical nature of EMR is determined by the interaction of Y-quanta of instantaneous radiation from a nuclear explosion with atoms of air gases: Y-quanta knock out electrons from atoms (the so-called Compton electrons), which move at enormous speed in the direction from the center of the explosion. The flow of these electrons interacting with magnetic field Earth, creates a pulse of electromagnetic radiation. When a megaton-class charge explodes at altitudes of several tens of kilometers, the tension electric field on the earth's surface can reach tens of kilovolts per meter.

Based on the results obtained during the tests, US military experts launched research in the early 80s aimed at creating another type of third-generation nuclear weapon - Super-EMP with an enhanced output of electromagnetic radiation.

To increase the yield of Y-quanta, it was proposed to create a shell of a substance around the charge, the nuclei of which, actively interacting with the neutrons of a nuclear explosion, emit high-energy Y-radiation. Experts believe that with the help of Super-EMP it is possible to create a field strength at the Earth's surface of the order of hundreds and even thousands of kilovolts per meter.

According to the calculations of American theorists, the explosion of such a charge with a capacity of 10 megatons at an altitude of 300-400 km above the geographic center of the United States - the state of Nebraska - will disrupt the operation of radio-electronic equipment throughout almost the entire territory of the country for a time sufficient to disrupt a retaliatory nuclear missile strike.

The further direction of work on the creation of Super-EMP was associated with enhancing its destructive effect by focusing Y-radiation, which should have led to an increase in the amplitude of the pulse. These properties of Super-EMP make it a first-strike weapon designed to disable government and military control systems, ICBMs, especially mobile-based missiles, missiles on a trajectory, radar stations, spacecraft, power supply systems, etc. Thus, Super EMP is clearly offensive in nature and is a first strike destabilizing weapon.

Penetrating warheads - penetrators

The search for reliable means of destroying highly protected targets led US military experts to the idea of ​​using the energy of underground nuclear explosions for this purpose. When nuclear charges are buried in the ground, the proportion of energy spent on the formation of a crater, a destruction zone and seismic shock waves increases significantly. In this case, with the existing accuracy of ICBMs and SLBMs, the reliability of destroying “point”, especially durable targets on enemy territory is significantly increased.

Work on the creation of penetrators was started by order of the Pentagon back in the mid-70s, when the concept of a “counterforce” strike was given priority. The first example of a penetrating warhead was developed in the early 1980s for the Pershing 2 medium-range missile. After the signing of the Intermediate-Range Nuclear Forces (INF) Treaty, the efforts of US specialists were redirected to the creation of such ammunition for ICBMs.

The developers of the new warhead encountered significant difficulties associated, first of all, with the need to ensure its integrity and performance when moving in the ground. The enormous overloads acting on the warhead (5000-8000 g, g-gravity acceleration) place extremely stringent demands on the design of the ammunition.

The destructive effect of such a warhead on buried, particularly strong targets is determined by two factors - the power of the nuclear charge and the extent of its penetration into the ground. Moreover, for each charge power value there is an optimal depth value at which the greatest efficiency of the penetrator is ensured.

For example, the destructive effect of a 200 kiloton nuclear charge on particularly hard targets will be quite effective when it is buried to a depth of 15-20 meters and it will be equivalent to the effect of a ground explosion of a 600 kiloton MX missile warhead. Military experts have determined that with the accuracy of delivery of the penetrator warhead, characteristic of the MX and Trident-2 missiles, the probability of destroying an enemy missile silo or command post with one warhead is very high. This means that in this case the probability of target destruction will be determined only by the technical reliability of the delivery of warheads.

Obviously, penetrating warheads are designed to destroy enemy government and military control centers, ICBMs located in silos, command posts, etc. Consequently, penetrators are offensive, “counterforce” weapons designed to deliver a first strike and, as such, have a destabilizing nature.

The importance of penetrating warheads, if adopted, could increase significantly in the context of a reduction in strategic offensive weapons, when a decrease in combat capabilities for delivering a first strike (a decrease in the number of carriers and warheads) will require an increase in the probability of hitting targets with each ammunition. At the same time, for such warheads it is necessary to ensure a sufficiently high accuracy of hitting the target. Therefore, the possibility of creating penetrator warheads equipped with a homing system at the final part of the trajectory, similar to high-precision weapons, was considered.

Nuclear-pumped X-ray laser

In the second half of the 70s, research began at the Livermore Radiation Laboratory to create " anti-missile weapons of the 21st century" - an X-ray laser with nuclear excitation. From the very beginning, this weapon was conceived as the main means of destroying Soviet missiles in the active part of the trajectory, before the warheads were separated. The new weapon was given the name “multiple launch rocket weapon.”

In schematic form, the new weapon can be represented as a warhead, on the surface of which up to 50 laser rods are attached. Each rod has two degrees of freedom and, like a gun barrel, can be autonomously directed to any point in space. Along the axis of each rod, several meters long, a thin wire of dense active material, “such as gold,” is placed. A powerful nuclear charge is placed inside the warhead, the explosion of which should serve as an energy source for pumping lasers.

According to some experts, to ensure the destruction of attacking missiles at a range of more than 1000 km, a charge with a yield of several hundred kilotons will be required. The warhead also houses an targeting system with a high-speed, real-time computer.

To combat Soviet missiles, US military specialists developed special tactics for its combat use. For this purpose, it was proposed to place nuclear laser warheads on submarine-launched ballistic missiles (SLBMs). In a “crisis situation” or during the period of preparation for a first strike, submarines equipped with these SLBMs must secretly move into patrol areas and take up combat positions as close as possible to the position areas of Soviet ICBMs: in the northern part of the Indian Ocean, in the Arabian, Norwegian, Okhotsk seas.

When a signal is received to launch Soviet missiles, submarine missiles are launched. If Soviet missiles rose to an altitude of 200 km, then in order to reach line-of-sight range, missiles with laser warheads need to rise to an altitude of about 950 km. After this, the control system, together with the computer, aims the laser rods at the Soviet missiles. As soon as each rod takes a position in which the radiation hits the target exactly, the computer will give a command to detonate the nuclear charge.

The enormous energy released during the explosion in the form of radiation will instantly transform active substance rods (wire) into a plasma state. In a moment, this plasma, cooling, will create radiation in the X-ray range, spreading in airless space for thousands of kilometers in the direction of the axis of the rod. The laser warhead itself will be destroyed in a few microseconds, but before that it will have time to send powerful pulses of radiation towards the targets.

Absorbed in a thin surface layer of rocket material, X-rays can create an extremely high concentration of thermal energy in it, which will cause it to evaporate explosively, leading to the formation of a shock wave and, ultimately, to the destruction of the shell.

However, the creation of the X-ray laser, which was considered the cornerstone of Reagan's SDI program, encountered great difficulties that have not yet been overcome. Among them, the difficulties of focusing laser radiation, as well as creating an effective system for pointing laser rods, are in the first place.

The first underground tests of an X-ray laser were carried out in the Nevada adits in November 1980 under the code name "Dauphine". The results obtained confirmed the theoretical calculations of scientists, however, the output of X-ray radiation turned out to be very weak and clearly insufficient to destroy missiles. This was followed by a series of test explosions “Excalibur”, “Super-Excalibur”, “Cottage”, “Romano”, during which the specialists pursued the main goal - to increase the intensity of X-ray radiation through focusing.

At the end of December 1985, an underground Goldstone explosion with a yield of about 150 kt was carried out, and in April of the following year, the Mighty Oak test was carried out with similar goals. Under the ban on nuclear testing, serious obstacles arose in the creation of these weapons.

It must be emphasized that an X-ray laser is, first of all, a nuclear weapon and, if detonated near the surface of the Earth, it will have approximately the same destructive effect as a conventional thermonuclear charge of the same power.

"Hypersonic Shrapnel"

During the work on the SDI program, theoretical calculations and simulation results of the process of intercepting enemy warheads showed that the first echelon of missile defense, designed to destroy missiles in the active part of the trajectory, will not be able to completely solve this problem. Therefore, it is necessary to create combat weapons capable of effectively destroying warheads during their free flight phase.

For this purpose, US experts proposed using small metal particles accelerated to high speeds using the energy of a nuclear explosion. The main idea of ​​such a weapon is that at high speeds, even a small dense particle (weighing no more than a gram) will have large kinetic energy. Therefore, upon impact with a target, the particle can damage or even pierce the warhead shell. Even if the shell is only damaged, upon entering the dense layers of the atmosphere it will be destroyed as a result of intense mechanical impact and aerodynamic heating.

Naturally, if such a particle hits a thin-walled inflatable decoy target, its shell will be pierced and it will immediately lose its shape in a vacuum. The destruction of light decoys will greatly facilitate the selection of nuclear warheads and, thus, will contribute to the successful fight against them.

It is assumed that, structurally, such a warhead will contain a nuclear charge of relatively low power with automatic system detonation, around which a shell is created consisting of many small metal destructive elements. With a shell mass of 100 kg, more than 100 thousand fragmentation elements can be obtained, which will create a relatively large and dense lesion field. During the explosion of a nuclear charge, a hot gas is formed - plasma, which, scattering at enormous speed, carries along and accelerates these dense particles. A difficult technical challenge in this case is maintaining a sufficient mass of fragments, since when a high-speed gas flow flows around them, mass will be carried away from the surface of the elements.

In the United States, a series of tests was carried out to create “nuclear shrapnel” under the Prometheus program. The power of the nuclear charge during these tests was only a few tens of tons. When assessing the destructive capabilities of this weapon, it should be borne in mind that in the dense layers of the atmosphere, particles moving at speeds of more than 4-5 kilometers per second will burn up. Therefore, “nuclear shrapnel” can only be used in space, at altitudes of more than 80-100 km, in airless conditions.

Accordingly, shrapnel warheads can be successfully used, in addition to combating warheads and decoys, also as anti-space weapons to destroy military satellites, in particular those included in the missile attack warning system (MAWS). Therefore, it is possible to use it in combat in the first strike to “blind” the enemy.

The various types of nuclear weapons discussed above by no means exhaust all the possibilities in creating their modifications. This, in particular, concerns nuclear weapons projects with an enhanced effect of an airborne nuclear wave, an increased yield of Y-radiation, increased radioactive contamination of the area (such as the notorious “cobalt” bomb), etc.

Recently, the United States has been considering projects for ultra-low-power nuclear charges.:
- mini-newx (capacity hundreds of tons),
— micro-news (tens of tons),
- Tiny-news (units of tons), which, in addition to low power, should be significantly more “clean” than their predecessors.

The process of improving nuclear weapons continues and it cannot be ruled out that in the future the appearance of subminiature nuclear charges created using super-heavy transplutonium elements with a critical mass from 25 to 500 grams. The transplutonium element Kurchatovium has a critical mass of about 150 grams.

A nuclear device using one of the California isotopes will be so small in size that, with a power of several tons of TNT, it can be adapted for firing from grenade launchers and small arms.

All of the above indicates that the use of nuclear energy for military purposes has significant potential and continued development in the direction of creating new types of weapons can lead to a “technological breakthrough” that will lower the “nuclear threshold” and have an impact on bad influence for strategic stability.

The ban on all nuclear tests, if it does not completely block the development and improvement of nuclear weapons, then significantly slows them down. In these conditions, mutual openness, trust, the elimination of acute contradictions between states and, ultimately, the creation of an effective international system of collective security acquire special importance.

/Vladimir Belous, Major General, Professor of the Academy of Military Sciences, nasledie.ru/