A general term for weapons that can self-sustain the energy released by nuclear fission or fusion reactions to produce explosive effects and have a large-scale destruction effect. Among them, fission weapons mainly made of fission chain reaction principles of heavy atomic nuclei such as uranium 235 (U-235) or plutonium 239 (239Pu), are usually called atomic bombs; thermonuclear weapons or fusion weapons mainly made of thermonuclear reaction principles of light atomic nuclei such as heavy hydrogen (D, deuterium {dāo}) or super heavy hydrogen (T, tritium {chuān}), are usually called hydrogen bombs.

The energy released when coal, petroleum and other fossil fuels burn, comes from the synthesis reaction of carbon, hydrogen, and oxygen. Generally, chemical drugs such as Tyrant (*) release energy released from the decomposition reaction of compounds. In these chemical reactions, the nuclei such as carbon, hydrogen, oxygen, and nitrogen have not changed, but the combination states between each atom have changed. Nuclear reactions and chemical reactions are different. In nuclear fission or nuclear fusion reactions, the nuclei involved in the reaction are transformed into other nuclei, and atoms have also changed. Therefore, people are accustomed to calling this type of weapon atomic weapon. But in essence, it is the reaction and transformation of atoms, so it is more accurate to call nuclear weapons.

The energy released by nuclear weapons when they explode is much larger than conventional weapons that only contain chemical drugs. For example, the energy released by 1 kilogram of uranium is about 8×10^13 joules, which is about 20 million times larger than the energy released by 1 kilogram of uranium explosion. Therefore, the total energy released by the explosion of nuclear weapons, that is, the magnitude of its power, is often expressed by the amount of Tyrant drugs that release the same energy, and is called Tyrant equivalent. The Tyrant equivalent of various nuclear weapons equipped by the United States, the Soviet Union and other countries is only 1,000 tons, or even lower; the larger one is 10 million tons, or even higher.

The explosion of nuclear weapons not only releases huge energy, but also the nuclear reaction process is very rapid and can be completed in microseconds. Therefore, extremely high temperatures are formed within a small range around the explosion of nuclear weapons, heating and compressing the surrounding air to expand rapidly, and high-pressure shock waves are generated. Nuclear explosions on the ground and air will also form fireballs in the surrounding air, emitting strong light radiation. Nuclear reactions also produce various rays and radioactive material fragments; strong pulse rays radiated outward interact with surrounding matter, causing the growth and disappearance of current, and the result is electromagnetic pulses. These characteristics, different from chemical zha explosions, make nuclear weapons have unique killing and destructive effects such as strong shock waves, optical radiation, early nuclear radiation, radioactive contamination and nuclear electromagnetic pulses. The emergence of nuclear weapons has had a significant impact on the strategies and tactics of modern warfare.

Nuclear weapon systems are generally composed of nuclear warheads, projection tools and command and control systems, and nuclear warheads are their main components. Nuclear warheads are also called nuclear warheads, and are often used in substitutions with nuclear devices and nuclear weapons. In fact, nuclear devices refer to a combination of nuclear charges, other materials, detonation drugs and **, etc., which can be used for nuclear testing, but they cannot usually be used as reliable weapons; nuclear weapons refer to the entire nuclear weapon system including nuclear warheads.

[Edit this section] History

The emergence of nuclear weapons was the result of the major development of science and technology around the 1940s. In early 1939, German chemist O. Hahn and physicist F. Strassman published a paper on the phenomenon of nuclear fission of uranium atoms. Within a few weeks, scientists from many countries verified this discovery and further proposed the possibility of creating self-sustaining conditions for this fission reaction, thus opening up a broad prospect of using this new energy to create wealth for mankind. However, like many new scientific and technological discoveries in history, the development of nuclear energy was first used for military purposes, namely, to create a powerful atomic bomb, and its process was influenced and restricted by the social and political conditions at that time. Since 1939, due to the expansion of the war of aggression by fascist Germany, many European countries have been conducting scientific research increasingly.

Difficulty. In early September of the same year, Danish physicist N.H.D. Bohr and his collaborator J.A. Wheeler theoretically explained the nuclear fission reaction process and pointed out that the best element that can cause this reaction was the isotope uranium 235. Just as this guiding research result was published, Britain and France declared war on Germany. In the summer of 1940, the German army occupied France. Some scientists led by French physicist J.-F. Jorio Curie were forced to move abroad. Britain had planned to conduct research in this field, but due to the influence of the war, there was a shortage of manpower and material resources. Later, it could only cooperate with the United States and sent a team of scientists led by physicist J. Chadwick to the United States to participate in the development of atomic bombs led by theoretical physicist J.R. Oppenheimer.

In the United States, Hungarian physicist Zillard Leo, who moved from Europe, first considered that once fascist Germany mastered the atomic bomb technology, it could have serious consequences. After he and several other scientists who moved to the United States from Europe, he wrote a letter to the 32nd President of the United States F.D. Roosevelt in August 1939, suggesting the development of an atomic bomb, which attracted the attention of the US government. However, it was only allocated $6,000 until the Japanese attack in December 1941.

It was only after the attack on Pearl Harbor that it expanded its scale. By August 1942, it developed into a huge plan code-named "Manhattan Engineering Zone", directly employed about 600,000 manpower and invested more than 2 billion US dollars. By the end of World War II, three atomic bombs were made, making the United States the first country to have an atomic bomb. Making atomic bomb was to solve a series of scientific and technological problems in the development of weapons, but also to be able to produce the necessary nuclear charge uranium 235 and plutonium 239. The isotope uranium 235 in natural uranium

The abundance is only 0.72%, and according to the design requirements of the atomic bomb, it must be increased to more than 90%. At that time, after many ways of exploration, research and comparison, the United States adopted three methods of electromagnetic separation, gas diffusion and heat diffusion to produce this highly enriched uranium. The dozens of kilograms of highly enriched uranium used for a "gun method" atomic bomb were produced by electromagnetic separation. The cost of building an electromagnetic separation factory was about US$300 million (the conductive coil of magnet is made of silver borrowed from the treasury, and its value has not been included). Plutonium 239 needs

The method of irradiating uranium 238 in the reactor was made by neutron irradiation. The dozens of kilograms of plutonium 239 used for the two "implosion" atomic bombs were produced using three graphite slowed-down, water-cooled natural uranium reactors and supporting chemical separation factories. The above examples can illustrate the scale of the project at that time. Since the United States' industrial technology facilities and construction were not directly threatened by war, it also mastered the necessary resources and concentrated a group of domestic and foreign scientific and technological talents to enable it to realize the atomic bomb development plan faster.

Germany's science and technology were at the leading position at that time. Before 1942, Germany's level in the field of nuclear technology was roughly the same as that of the United States and Britain, but later it fell behind. The first experimental graphite reactor in the United States was built and reached a critical point under the leadership of physicist E. Fermi. Germany used a heavy water reactor to produce plutonium 239, and it was not until early 1945 that a small subcritical device was built. In order to produce highly enriched uranium, Germany focused on the production of

The development of high-speed centrifuges was slow due to air strikes, electricity, and lack of materials. Secondly, A. Hitler persecuted scientists and some scientists with a disco-cooperation attitude, which was another reason for the unfast progress in this area. More importantly, the German fascist leader was overconfident and believed that the war could end soon and did not need to spend time developing an atomic bomb that was not sure. First, he did not support it, and then he was unable to catch it. The development work finally failed.

Fatty (atomic bomb dropped on Nagasaki) After Germany surrendered in May 1945, many people in the United States who knew the inside story of the "Manhattan Project", including a large number of scientists engaged in this work, opposed the use of atomic bombs to bomb Japanese cities. At that time, the Japanese invaders were hit hard by the Chinese people's long-term resistance, and their strength was greatly weakened. The attacks of the United States and Britain in the Pacific region almost completely destroyed the Japanese navy, and the maritime blockade made Japan's domestic supply extremely scarce. With the failure of Japan being a foregone conclusion, the United States still dropped the only two atomic bombs on Hiroshima and Nagasaki in Japan on August 6 and 9, codenamed "Little Boy" and "Fatty".

Before the German invasion in June 1941, the Soviet Union also carried out the development of atomic bombs. The spontaneous fission of the uranium nucleus was discovered by Soviet physicists A. Frerov and Petzak during this period. After the outbreak of the Patriotic War, the development was forced to be interrupted. It was not until early 1943 that it gradually recovered under the leadership of physicist A. Kurchatov and accelerated after the war. In August 1949, the Soviet Union conducted atomic bomb tests. In January 1950

US President H.S. Truman ordered the accelerated development of hydrogen bombs. In November 1952, the United States conducted a principle test of hydrogen bombs using liquid deuterium as thermonuclear fuel, but the experimental device was very bulky and could not be used as a weapon. In August 1953, the Soviet Union conducted a hydrogen bomb test using solid lithium deuterated 6 as thermonuclear fuel, making the practicality of hydrogen bombs possible. The United States conducted a similar hydrogen bomb test in February 1954. Britain and France also conducted atomic bomb and hydrogen bomb tests in the 1950s and 1960s.

During the period when China began to build socialism in an all-round way, the basic industry developed to a certain extent, that is, to prepare for the development of an atomic bomb. When it started in 1959, the national economy encountered serious difficulties. In June of the same year, the Soviet government tore up the agreement on new national defense technology signed by China and the Soviet Union in October 1957, and then withdrew experts. China was determined to rely entirely on its own strength to achieve this task. The atomic bomb in China's first test was codenamed "596", which was used to encourage the military and civilians across the country to work together to do this work. On October 16, 1964, the first atomic bomb test was successful. After more than two years, on December 28, 1966, the principle test of small-equivalent hydrogen bomb was successfully tested; half a year later, on June 17, 1967, a million-ton hydrogen bomb airdrop test was successfully carried out. China adhered to the policy of independence and self-reliance, and completed the tasks of the two development stages of nuclear weapons at the fastest speed in the world.

On August 6 and 9, 1945, on the eve of the end of World War II, the US Air Force threw two atomic bombs in Hiroshima and Nagasaki in Japan. This huge disaster in history caused more than 100,000 Japanese civilians to be killed and injured more than 80,000 people. The unprecedented killing and destructive power of the atomic bomb shocked the world and gave people a new understanding of new weapons made by using the huge explosive power of fission or fusion of atomic nuclei.

At present, what people usually call nuclear weapons refers to weapons with huge lethality created by the huge energy and destructive power generated by the fission or fusion of atomic nucleus, that is, weapons that use energy that can automatically maintain the instant release of nuclear fission or fusion chain reaction to produce explosive effects and have a large-scale killing and destructive effect.

The basic principle of fission nuclear weapons is to transform a certain amount of uranium-235 or plutonium-239 from a subcritical state to a supercritical state, that is, the speed at which the nuclear device generates neutrons is greater than the speed at which the neutron escapes from the nuclear device. There are two ways to achieve this transformation: one is to divide the nuclear device into two parts, each part is too small to have a positive neutron proliferation rate, and then use a gun-type device to hit the two parts into one; the other is to wrap the spherical nuclear device in the subcritical state with strong chemical drugs, and compress the nuclear device into a supercritical state by detonation.

Fusion nuclear weapons cause detonation conditions to be generated in thermonuclear fuels such as deuterium or lithium tritiated, using the method of fission nuclear bombs to make the thermonuclear fuel in nuclear weapons have a high temperature of 100,000-200,000,000℃, thereby causing nuclear fusion.

Atomic bombs and hydrogen bombs are usually expressed in units of kilotons or megatons of TNT (TNT) equivalents. For example, in the fission nuclear bombs that the United States threw in Hiroshima in 1945, the energy released by less than 50 kilograms of uranium is equivalent to 20,000 tons of chemical drugs. Various fusion nuclear bombs, namely thermonuclear bombs (hydrogen bombs), have a power of up to 60,000 megatons. It is calculated that when a nuclear weapon explodes, the energy released by the entire fission of 1 kilogram of uranium-235 is equivalent to the energy released by 20,000 tons of TNT, and the energy released by the mixture of 1 kilogram of deuterium and tritium is about 3-4 times the energy released by the complete fission of 1 kilogram of uranium-235.

[Edit this section] Current status and classification

The two atomic bombs dropped by the United States on Japan were in the form of nuclear missiles with parachutes and used aircraft as carrier tools. Later, with the development of weapon technology, a variety of nuclear weapon systems have been formed, including ballistic nuclear missiles, cruise nuclear missiles, air defense nuclear missiles, anti-missile nuclear missiles, anti-submarine nuclear rockets, deep-water nuclear bombs, nuclear aviation bombs, nuclear artillery shells, nuclear mines, etc. Among them, ballistic nuclear missiles equipped with multiple warheads and cruise nuclear missiles with various launch methods are the main nuclear weapons equipped by the United States and the Soviet Union.

Nuclear weapons are usually divided into two categories according to their combat use, namely strategic nuclear weapons used to attack enemy strategic targets and defend their own strategic locations, and tactical nuclear weapons mainly used to attack enemy combat forces on the battlefield. The Soviet Union also divided them into "combat tactical nuclear weapons". The classification method of nuclear weapons is related to geographical conditions and socio-political factors, and is not very strict. Since the late 1970s, US official documents rarely used "tactical nuclear weapons", and replaced them include "war zone nuclear weapons", "non-strategic nuclear weapons", etc., and medium-range and medium-range nuclear missiles are also classified into this category.

According to the design of the nuclear warhead, the nuclear weapons mainly belong to the two types of atomic bombs and hydrogen bombs. As for the number of nuclear weapons, there is no accurate published figure, and the estimated figures of relevant research institutions are not consistent. According to comprehensive analysis of data in recent years, by the mid-1980s, the United States and the Soviet Union had a total of about 50,000 nuclear warheads, accounting for more than 95% of the world's total. The total equivalent was about 12 billion tons. During World War II, the United States invested in Germany and Japan.

The bombs under the total amount is about 2 million tons*, which is only equivalent to the equivalent of the two hydrogen bombs carried by the US B-52 bomber. From this rough comparison, we can see the huge storage capacity of the nuclear arsenal. The number and equivalent comparison of the offensive strategic nuclear weapons of the US and the Soviet Union (including intercontinental nuclear missiles, ballistic nuclear missiles, cruise nuclear missiles and strategic bombers launched by submarines) are compared in terms of quantity and equivalent. The United States is less than that of the Soviet Union in terms of projection tools (land-based launchers, submarine launchers, aircraft) and the total equivalent value of the US is less than that of the Soviet Union, but in the nuclear warheads.

More than the Soviet Union. Considering that the damage effect and equivalent size of the target opposite the nuclear explosion is not a simple proportional relationship, another estimation method is to measure the damage ability of the nuclear warhead based on the damage area corresponding to a certain shock wave overpressure, that is, to take the 2/3 power of the nuclear warhead equivalent value (calculated in million tons as unit) as its "equivalent million tons equivalent" value (also according to different situations such as the target characteristics and distribution and the size of the nuclear attack, other directions less than 2/3 are selected), and then the number of various nuclear warheads is

The total value is calculated. According to this method, the strategic nuclear weapons destruction capabilities of the United States and the Soviet Union are estimated to be more important than the number of nuclear warheads with an equivalent of less than one million tons, and the United States is more than the Soviet Union. However, since the 1980s, with the development of the Soviet Union's nuclear weapons in sub-guided multi-warhead missiles, this gap has been widening. The destruction capabilities of point (hard) targets (see point targets), nuclear weapons destruction play a more important role, because the United States has always been ahead in this regard and is still in an advantage.

In addition to the United States, the Soviet Union, Britain, France and China, India conducted a nuclear test in 1974. It is generally believed that countries that master necessary nuclear technology and have a certain industrial foundation and economic strength are also completely possible to create atomic bombs.

[Edit this section] Development and testing

In addition to the production of nuclear materials such as uranium 235 and plutonium 239, the development of the nuclear warhead itself must be coordinated with the development procedures of the entire nuclear weapon system. The development process is roughly as follows: Starting from the conceptual stage; after pre-research or feasibility study of key technical topics and components, several design plans including weight, size, form, power, nuclear materials, nuclear test requirements, development period, and funding are formed; then after argumentation, comparison and evaluation, design plans are selected, tactical technical indicators are determined; then model research and design design, various simulation tests are carried out; process tests and trial production are carried out, and the rationality of the design is tested through nuclear tests, and finally the design is finalized, process finalized and approved production is achieved. To carry out these work, there must be a special scientific and technological team and equipped with necessary testing sites, including nuclear testing sites. After the weapons are delivered to the troops, the development and production departments must also provide maintenance, repair, replacement of components and other services, make necessary improvements according to the feedback information, and be responsible for their decommissioning or renewal.

To design the nuclear warhead, the US B57 type atomic bomb must have a deep understanding of its reaction process, clarify the conditions and various physical parameters, and master the internal connection and change laws of many factors. To this end, a series of scientific and technological problems in multiple disciplines such as nuclear physics, neutron physics, high temperature and high pressure condensed matter physics, supersonic fluid mechanics, detonation science, computational mathematics and materials science should be studied. The development practice of the nuclear warhead will in turn drive and promote the development of these disciplines. During the development process, the following links will start.

It plays an important role: ① Use fast, large-capacity electronic computers to conduct theoretical research and calculations of the reaction process. This calculation should be as close to the actual situation as possible to find the optimal solution from various ideas or design solutions, thereby saving costs and reducing the number of nuclear tests. Since the 1940s, one of the important factors that have promoted the rapid development of electronic computer technology is precisely due to the needs of nuclear weapons development. ② According to the requirements of the plan or indicators, multiple simulation tests should be carried out repeatedly, including chemical zha drug detonation tests, materials and strength tests

, environmental condition tests, control, ignition and safety tests, etc. These are essential to achieve the high reliability and safety of nuclear weapons. ③ Necessary nuclear tests must be carried out. Whether it is a large number of calculations on electronic computers or corresponding simulation tests, it cannot reach the real situation of the nuclear weapon scheme 100%. In particular, the high temperature conditions required for hydrogen bomb fusion reaction can only be provided by fission reactions (using the inertial constraint technology of laser or particle beams to create this simulated test condition, which was still in the research stage until the early 1980s)

. Therefore, whether the design requirements can be met must be tested through the explosion test of the nuclear device itself. Of course, the role of nuclear tests is not limited to this. It is precisely because nuclear tests play a key role in the development of nuclear weapons that the United States and the Soviet Union signed a Treaty on the Prohibition of Nuclear Weapon Testing in the Atmospheric, Outer Space and Underwater in 1963, which does not prohibit underground nuclear tests. In 1974, a Treaty on the Prohibition of Nuclear Weapon Testing in the Atmospheric, Outer Space and Underwater was signed. Atmospheric Experiment

According to the explosion environment, it can be divided into:

Atmosphere explosion

That is, conduct nuclear explosion tests in a naked atmosphere environment, which is the most destructive (indicated in the impact on people). In an environment where there is no good escape facilities, people within a dozen square kilometers will be severely traumatized or even die.

Underground nuclear explosion

Underground experiments are generally scientific experiments, and some military experts believe that underground nuclear explosions can artificially cause "natural disasters" such as earthquakes and tsunamis to hostile countries. However, this kind of damage is difficult to control, so it has not been recognized by many military experts.

Underwater nuclear explosion

The tests are mainly conducted in the sea. The United States once conducted them in the 1950s. After the explosion, all ships failed to withstand the huge explosion power of nuclear bombs. Of course, nuclear explosion tests also caused extremely harsh damage to the local natural ecological environment.

[Edit this section] Development trend

Due to the improvement of the accuracy of nuclear weapons projection tools, since the 1960s, the development of nuclear weapons has firstly reduced the weight of the nuclear warhead, but still maintained a certain power, that is, it has significantly improved its power (the ratio of power to weight). For example, the atomic bomb dropped by the United States in Nagasaki weighs about 4.5 tons and its power is about 20,000 tons; in the late 1970s, the "Trident" I submarine missile equipped with the troops had a total weight of about 1.32 tons, a total of 8 sub-guided bullets, each of which was 100,000 tons, which was the same as that of Nagasaki.

Compared with the atomic bomb, the atomic bomb is about 135 times higher. The more powerful thermonuclear weapons are even greater than the power. However, it is generally believed that the development in this aspect may be close to the limit allowed by objective reality. Since the 1970s, the development of nuclear weapons systems has focused more on improving the survivability and hit accuracy of weapons. For example, the United States' "Peace Guardian/MX" intercontinental missile, the "Gnome" small intercontinental missile, the "Trident II submarine missile, the Soviet SS-24 and SS-25 intercontinental missiles have all made great improvements and improvements in these aspects.

Secondly, the reliability of the nuclear warhead and its detonation control security insurance subsystem, as well as the ability to adapt to various use and combat environments, have also been improved and improved. The United States and the Soviet Union have also developed various nuclear weapons suitable for use on the battlefield, such as variable-equivalent nuclear warheads, and nuclear warheads with a variety of carriers. They even envisioned the development of micro-nuclear weapons with an equivalent of only a few tons. Especially in the nuclear war environment, how to improve the nuclear resistance to nuclear reinforcement capabilities to prevent enemy damage has been more widely paid attention to. In addition, due to the large-scale production and deployment of nuclear weapons, their security has also attracted the attention of relevant countries.

Another development trend of nuclear weapons is to adjust their performance through design and enhance or weaken certain destructive factors in them according to different needs. "Enhanced radiation weapons" and "Reduce residual radioactive weapons" both belong to this category. The former increases the share of high-energy neutron radiation as much as possible, making it the main destructive factor, commonly called neutron bullets; the latter minimizes residual radioactivity and highlights the role of shock waves and optical radiation, but this type of weapon still belongs to the category of thermonuclear weapons. As for the so-called "pure fusion weapons" that caused widespread discussion in the early 1960s, although a lot of research has been done over the past 20 years, such as the research on igniting fusion reactions of high-power lasers, and it has continued in the 1980s, but there is no real possibility of making such weapons.

Although the practical application of nuclear weapons is still limited to the two atomic bombs when it was launched, due to the development of nuclear weapons themselves over the past 40 years, as well as the development and application of various projection or carrier tools related to it, especially the knowledge accumulated through thousands of nuclear tests, people have a deep understanding of their unique destructive and destructive effects, and have explored possible ways to apply them in practice. Both the United States and the Soviet Union have formulated and revised various strategies that emphasize the important role of nuclear weapons.

There must be a shield. While constantly improving and improving the performance of offensive strategic nuclear weapons, the United States and the Soviet Union have also been seeking means and technologies to effectively defend against nuclear attacks. In addition to improving the nuclear weapon system's anti-nuclear reinforcement capabilities and taking measures to reduce losses such as building basement bunkers and civil defense projects to reduce losses, the development and research on defense technology development of more effective reconnaissance, tracking, identification, and intercepting the opponent's nuclear missiles has never stopped. In the 1960s, the United States and the Soviet Union deployed anti-nuclear anti-missile systems.

In May 1972, the United States and the Soviet Union signed the Treaty on Restricting Anti-Ballistic Missile Systems. Soon, the United States stopped the deployment of the "Guard" anti-missile system. In early 1984, the United States claimed that it had formulated a "strategic defense initiative" including nuclear-stimulated directional energy weapons, high-energy lasers, neutral particle beams, non-nuclear interceptor bombs, electromagnetic guns and other multi-layer interception methods. Although there is still controversy over the effectiveness of this defense system, it is certain that the United States and the Soviet Union's competition for nuclear advantages will continue.

Because nuclear weapons have huge destructive power and unique roles, it is better to say that they have and are constantly affecting the real international political struggle than to change the course of future global wars. In the late 1970s, the United States announced the successful development of neutron bullets. It is most suitable for battlefield use and should belong to the category of tactical nuclear weapons, but it has been strongly opposed almost worldwide. From this example, it can also be seen that the complexity of the struggle involved in nuclear weapons.

The Chinese government issued a statement when the first atomic bomb was exploded: China's development of nuclear weapons is not because it believes in the omnipotence of nuclear weapons, but because it wants to use nuclear weapons. On the contrary, China's development of nuclear weapons is forced to do it, for defense, to break the nuclear monopoly of nuclear powers, nuclear blackmail, to prevent nuclear war and eliminate nuclear weapons. Since then, the Chinese government has solemnly announced many times that at any time and under any circumstances, China will not use nuclear weapons first, and has repeatedly made suggestions on how to prevent nuclear war. These claims of China have gradually been approved and supported by more and more countries and people.

[Edit this section] Reference Book

Zhao Zhongyao, He Zehui, and Yang Chengzong Editor: "The Principles and Applications of Atomic Energy", Science Press, Beijing, 1965.

Thomas B. Cochran, Waiting, Ke Qingshan, et al. translated by: "Nuclear Weapons Manual", PLA Press, Beijing, 1985. (Thomas B. Cochran, William M. Arkin, and Milton M. Hoenig, Nuclear Weapons Databook, U.S. Nuclear Forces and Capabilities, Natural Resources Defense Council Inc., 1984.)

Written by Bertrand Goldschmidt, translated by Gao Qiang, Lu Hanen: "Atomic Competition 1939-1966", Atomic Energy Press, Beijing, 1984. (Bertrand Goldschmidt, Les Rivalités Atomiques 1936-1966, Fayard, 1967.)

Written by Robert Junker, translated by He Wei: "Brighter than a Thousand Suns", Atomic Energy Press, Beijing, 1980. (Robert Jungk, Helleralstausend Sonnen, 1956.)

[Edit this section] Atomic bomb

atomicbomb

Using heavy nuclear fission reactions such as uranium-235 or plutonium-239,

Nuclear weapons that instantly release huge energy, also known as fission bombs. The power of atomic bombs is usually several hundred to tens of thousands of tons, with huge lethality and destructive power. They can be carried by different carriers and become nuclear missiles, nuclear aviation bombs, nuclear landmines or nuclear artillery shells, etc., or used as primary (or trigger) in hydrogen bombs, providing the necessary energy for ignition of light nuclear and causing thermonuclear fusion reactions.

The atomic bomb is mainly composed of a detonation control system, a high-energy drug, a reflective layer, a nuclear component composed of nuclear charge, a neutron source and a shell casing and other components. The detonation control system is used to detonate a high-energy drug; a high-energy drug is the energy that pushes and compresses the reflective layer and nuclear components; the reflective layer is composed of beryllium or uranium-238. Uranium-238 can not only reflect neutrons, but also has a high density, which can slow down the expansion of the nuclear charge during the release of energy, and maintain the chain reaction for a long time, thereby increasing the explosion power of the atomic bomb. The nuclear charge is mainly uranium-235 or plutonium-239.

In order to trigger a chain reaction, a neutron source must provide "ignited" neutrons. The neutron sources of nuclear explosion devices can be used: deuterium-tritium reaction neutron sources, polonium-210-beryllium sources, plutonium-238 atomic bomb explosion beryllium sources and sulfonium-252 spontaneous fission sources, etc. The high temperature and high pressure generated by atomic bomb explosion and the neutrons, gamma rays and fission fragments produced by various nuclear reactions, ultimately forming shock waves, optical radiation, early nuclear radiation, radioactive contamination and electromagnetic pulses and other killing and destructive factors. The atomic bomb is a prominent example of the rapid application of the latest achievements of science and technology to the military. In October 1939, the US government decided to develop an atomic bomb. Three were built in 1945. One was used for testing, and two were dropped in Japan. The time when other countries exploded the first atomic bomb was: the Soviet Union - August 29, 1949; Britain - October 3, 1952; France - February 13, 1960; China - October 16, 1964; India - May 18, 1974. China's first nuclear test was conducted in the form of tower explosion, using the "internal detonation" uranium bomb. During the second nuclear test on May 14, 1965, nuclear equipment was airdropped by aircraft. During the fourth nuclear test on October 27, 1966, the nuclear warhead was carried by a missile.

Since the advent of the atomic bomb in 1945, atomic bomb technology has been continuously developed, with significantly reduced volume and weight, and tactical and technical performance increasing. The miniaturization of atomic bombs is of great significance to improving the tactical and technical performance of nuclear weapons and the detonation device used as a hydrogen bomb (also known as the "trigger"). In order to adapt to the needs of battlefield use, a variety of low-equivalent and adjustable nuclear weapons have been developed. In order to improve the performance of the atomic bomb, a reinforced atomic bomb was developed, that is, the addition of thermonuclear charges such as deuterium or tritium to the atomic bomb, and the energy released by nuclear fission was used to ignite it. Deuterium or tritium undergoes a thermonuclear reaction, and the high-energy neutrons released in the reaction make more nuclear charges fission, thereby increasing their power. Unlike hydrogen bombs, this atomic bomb, the energy released by its thermonuclear charge accounts for only a small part of the total equivalent. The detonation method and nuclear explosion device structure of high-energy zha drugs are also constantly improving, with the purpose of improving the utilization efficiency of zha drugs and the compression of nuclear charges, thereby increasing their power and saving nuclear charges. In addition, improving the penetration and survivability and safety performance of atomic bombs is also increasingly valued.

[Edit this section] History of the atomic bomb

●During World War II, in order to prevent the Germans from creating atomic bombs first, scientist Sillard mobilized the famous scientist Einstein to write a letter to US President Roosevelt, explaining the importance of developing atomic bombs to American security.

●On December 6, 1941 (the day before Japan's sneak attack on Pearl Harbor), Roosevelt approved the US Scientific Research and Development Agency to fully develop the atomic bomb.

●In August 1942, the United States formulated the "Manhattan Plan" to develop the atomic bomb.

●In July 1943, the United States established the Atomic Bomb Research Institute.

●In March 1945, the United States established the secret merger of the Atomic Energy Commission.

●On July 16, 1945, the world's first atomic bomb was tested in the Alamocod Desert in New Mexico.

●On August 6 and 9, 1945, the United States dropped an atomic bomb on Hiroshima and Nagasaki, Japan.

●In 1949, the Soviet Union successfully developed the atomic bomb. Britain and France exploded their own atomic bombs in 1952 and 1960 respectively. In 1964, China also owned the atomic bomb.

Atomic bombs are divided into two types: "gun type" and "collective type". Nuclear weapons produce devastating power in their unique ways.

According to the different atomic bomb initiation mechanisms, it can be divided into "gun type" atomic bombs and "polyte" atomic bombs. "gun type" atomic bombs separate two hemispherical cracking substances smaller than the critical volume at a certain distance, and the neutron source is located in the middle. A layer of solid material that can reflect neutrons on the spherical surface of the nuclear charge is coated with a solid material that can reflect neutrons. The function is to reflect the neutrons that run out prematurely to increase the speed of chain reaction. Outside the neutron reflective layer is a high-speed drug, a explosive drug and a **, and then connect the ** to the detonation controller. The detonation controller automatically detonates the drug. The two hemispherical fission substances are quickly compressed into a flat spherical shape under the bombardment of the drug, achieving super-submarine Critical state. The neutron source releases a large number of neutrons to make the chain reaction proceed quickly and releases great energy in a very short time. This is the explosion of the atomic bomb with huge lethality. The "polyzing" atomic bomb makes ordinary strong drugs into spherical devices, and makes a nuclear charge smaller than the critical volume into a small ball in the drug ball. The drug detonates at the same time, quickly pressing the nuclear charge ball to reach a supercritical volume, thereby causing a nuclear explosion. The structure of the "polyzing" atomic bomb is complex, but the utilization rate of nuclear charge is high. Modern atomic bombs combine these two initiating mechanisms to increase the utilization rate of nuclear charge to about 80%, thus obtaining great destructive power.

The main ways of killing and destroying nuclear weapons include optical radiation, shock waves, early nuclear radiation, electromagnetic pulses and radioactive contamination. Optical radiation is a radiation light-killing method released during nuclear explosions that spreads linearly at a speed of 300,000 kilometers per second. After an atomic bomb with an equivalent of 20,000 tons explodes in the air, it will be irradiated 7,000 meters away from the center of the explosion and will be irradiated 13 times stronger than the sun, with a range of 2,800 meters. Optical radiation can quickly blind people, and cause large-scale burns and ulcers on the skin, and objects will burn.

Shock wave is the overpressure of a huge airflow generated after a nuclear explosion. After a 30,000-ton atomic bomb explodes, the motion speed of the shock wave can reach 200 meters/sec at 800 meters from the center of the explosion. A nuclear explosion with an equivalent of 20,000 tons, within 650 meters from the center of the explosion, the overpressure value is greater than 1,000 grams/cm2. All buildings and personnel located in the area can be completely destroyed. Early nuclear radiation was the neutron flow and gamma ray released in the first few decades of the nuclear explosion. 1 equivalent

After a 20,000-ton atomic bomb explodes, people within 1,100 meters from the explosion center can be extremely injured. After a 1,000-ton neutron bomb explodes, people within this range will be killed within a few weeks, and people within 200 meters will be killed immediately. The electric field strength of the electromagnetic pulse can reach 10,000 to 100,000 volts within a range of several thousand meters, which can not only seriously damage the components of electronic equipment, but also break down insulation, burn circuits, cancel computer memory, and cause all radio command, control and communication equipment to fail.

.A 50 million tons-type atomic bomb has a destruction radius of up to 190 kilometers after the explosion. Radioactive contamination is the smoke and dust that falls after the mushroom-like smoke clouds drift away. It can cause irradiation or skin burns on the human body, resulting in death. On February 28, 1954, the 15 million tons-type hydrogen bomb tested on Bikini Island in the United States was 6 hours after the explosion, and the contamination area was as long as 257 kilometers and wide * kilometers. All living things within this range were sexually contaminated and died slowly or were disabled for a period of time.

[Edit this section] Comparison of nuclear weapons forces in five nuclear countries

The United States: The first nuclear test was successful in 1945. The number of nuclear tests exceeded 1,030. It has about 12,000 nuclear warheads. The missile range is 13,035 kilometers.

Soviet Union: The first nuclear test was successful in 1949. The number of nuclear tests exceeded 715. It has about 28,000 nuclear warheads, of which about 18,000 will be dismantled. The missile range is 10,943 kilometers.

Britain: The first nuclear test was successful in 1952. A total of 45 nuclear tests were conducted. It has about 400 nuclear warheads and the missile range is 5,310 kilometers.

France: The first nuclear test was successful in 1960. It has about 510 nuclear warheads and the missile range reaches 5,310 kilometers.

China: The first nuclear test was successful in 1964.

[Edit this section] Types of nuclear weapons

The US W87 hydrogen bomb nuclear bomb includes hydrogen bombs, atomic bombs, neutron bombs, three-phase bombs, antimatter bombs, etc. that are related to nuclear reactions.

The first generation: atomic bombs: nuclear bombs that are fissioned with heavy nuclear uranium or plutonium. The principle of atomic bombs is nuclear fission chain reaction - neutrons bombard uranium-235 or plutonium-239, causing their nuclei to crack and generate energy, including shock waves, instantaneous nuclear radiation, electromagnetic pulse interference, nuclear pollution, optical radiation and other killing effects.

The second generation: hydrogen bomb: hydrogen bomb is nuclear fission and nuclear fusion - the hydrogen bomb is detonated by the atomic bomb. The high-energy neutrons released by the atomic bomb react with lithium deuterated to generate tritium, and tritium and deuterium aggregate to generate energy. The hydrogen bomb explosion is actually two nuclear bombs explosions (atomic bombs and hydrogen bombs), so the power of hydrogen bombs is greater than that of atomic bombs. If it is loaded with the same amount of nuclear fuel, the power of hydrogen bombs is more than 4 times that of atomic bombs. Of course, it cannot be compared with a large-equivalent atomic bombs and a small-equivalent hydrogen bombs.

The "Hydrogen-uranium bomb" (three-phase bomb) is nuclear fission plus nuclear fusion plus nuclear fission - it adds another layer of fissionable uranium-238 to the outer layer of the hydrogen bomb, and it also belongs to the second-generation nuclear bomb.

The third generation: neutron bombs (enhanced radiation bombs): nuclear bombs made based on the principle of deuterium and tritium fusion and high-energy neutrons as the main lethality. Neutron bombs are a special type of small hydrogen bombs, which are nuclear fission and nuclear fusion - but not detonated with an atomic bomb, but bombarded plutonium-239 with an internal neutron source to produce fission. The high-energy neutrons and high temperatures generated by fission promote the fusion of deuterium-tritium mixture. Its characteristics are: high neutron energy, large quantity, and small equivalent. If the equivalent is large, it is similar to hydrogen bombs, and the shock wave and radiation will also increase dramatically, which will lose the purpose of "only killing people without destroying equipment and buildings, and not causing large-scale pollution". It also loses the small and exquisite characteristics. Neutron bullets are most suitable for killing tanks, bunkers, and underground commands.

Power sort: Hydrogen uranium bomb > Hydrogen bomb > Atomic bomb > Neutral bomb;

Radiation sorting: neutron bomb > hydrogen uranium bomb > hydrogen bomb > atomic bomb;

Pollution sorting: hydrogen uranium bomb > hydrogen bomb > atomic bomb > neutron bomb

The fourth generation: nuclear directed energy weapons: under development, because these nuclear bombs do not generate residual nuclear radiation, they can be used as "conventional weapons". The main types are:
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