1964 10 6 16 at 3pm, China's first atomic bomb exploded successfully in lop Nur, Xinjiang.

From 1958, it took China six years to develop "two bombs and one satellite" until the first atomic bomb exploded successfully. Subsequently, practical atomic bombs, two-bomb joint tests, hydrogen bombs and artificial satellites were successfully developed. The achievement of "two bombs and one satellite" has greatly enhanced China's international prestige. Deng Xiaoping, the second generation leader of our country, specifically said, "If China had no atomic bombs, hydrogen bombs and satellites since the 1960s, China could not be called a big country with important influence and would not have such an international status.

First of all, the first atomic bomb was an implosion uranium bomb.

Based on the collection of evidence such as radioactive dust from China's nuclear explosion, American intelligence agencies were surprised to find that China's first atomic bomb was far more advanced than they expected-596 was an implosion uranium bomb, which was much more difficult than the first atomic bomb of other countries.

Atomic bombs generally refer to fission nuclear bombs, and both uranium 235 and plutonium 239 can be used as nuclear charges for atomic bombs. Atomic bombs are generally divided into uranium bombs and plutonium bombs according to different charges. According to the detonation mode of atomic bomb, atomic bomb can be divided into gun type and implosion type. Because the separated plutonium -239 contains a certain amount of plutonium -240, and the gun design is more likely to induce premature ignition, so the gun design can only use uranium charge, while the implosion atomic bomb can choose plutonium and uranium nuclear charge.

The design and manufacture of gun-type atomic bomb is lower than that of implosion atomic bomb, but the gun-type design wastes too much nuclear charge material. The "little boy" dropped by the United States in Hiroshima was a gun-type uranium bomb. Only about 1 kg of uranium -235 charge of about 60 kg has nuclear fission, that is, only 1.7% of the charge material has nuclear fission, and the efficiency is extremely low. The utilization efficiency of nuclear charge designed by implosion is much higher, and there are problems in the selection of plutonium 239 and uranium 235 in implosion nuclear bomb. A nuclear bomb containing plutonium -239 has the disadvantage of short service life, but it is much easier to separate plutonium -239 than to enrich uranium -235. Plutonium -239 also has the advantages of large reaction cross section and small critical mass. For example, the critical mass of spherical uranium -235 is 52kg and there is no neutron reflector, while plutonium -239 only needs 10kg. Because the critical mass is smaller, it is easier to develop the core of implosion plutonium bomb. The first nuclear test in the United States (and the first atomic bomb in the world) was an implosion plutonium bomb, and the "fat man" who fell in Nagasaki was also an implosion plutonium bomb. Decades later, North Korea's first atomic bomb was also a plutonium bomb.

American intelligence once thought that China's first atomic bomb would definitely be an implosion plutonium bomb. They spent a lot of time and energy looking for China's plutonium -239 separation device, thus underestimating the development progress of China's atomic bomb.

China's first atomic bomb is not an implosion plutonium bomb, nor a gun-type uranium bomb with a simpler design, but an implosion uranium bomb, which is actually equivalent to applying the technology of implosion plutonium bomb to uranium bombs, with great technical difficulties and risks.

China has its own difficulties in choosing such a difficult design-the development of China's first atomic bomb is in a difficult period of national economy, and the gun-type uranium bomb needs too much uranium -235 nuclear material, but China's just-started uranium enrichment industry can't meet this demand for the time being. Therefore, based on the implosion design of plutonium bomb, an advanced implosion design uranium bomb was developed for the first nuclear explosion.

China's characteristic of making up for the lack of industrial capacity with superb design is often the normal state of China's nuclear weapons development, such as the later development of hydrogen bombs. It is worth mentioning that China's first atomic bomb was code-named "596" to commemorate that the Soviet Union tore up the agreement in June 1959 and stopped providing assistance to China's nuclear weapons program.

It took only two years and eight months from atomic bomb to hydrogen bomb.

In the history of China's nuclear weapons development, there is a record that the breakthrough speed from atomic bomb to hydrogen bomb is the fastest among the five nuclear powers. As a pioneer, the United States spent seven years and three months (1 945.7.15-1952.11) from the first atomic bomb to the first hydrogen bomb, while its cold war rival, the Soviet Union, spent about four years (. Britain, a staunch ally of the United States, spent four years and seven months (1952.10.3-1957.5.15) and France, an independent country, spent eight years and six months (1960.2./kloc-).

Now some people on the Internet think that China's short time is a "late-comer advantage". However, in 1950s and 1960s, nuclear powers such as the United States, the Soviet Union and Britain kept the development of hydrogen bombs highly confidential, so China could not learn from the successful experience and data of other countries. France, a western country, took eight years to leap from an atomic bomb to a hydrogen bomb, which in itself is the biggest denial of the "latecomer advantage" of brain tonic. If we must say that foreign experience is helpful to our country, it is that the United States, the Soviet Union and Britain, as pioneers, have informed the world that there are still hydrogen bombs, which are much more powerful than atomic bombs and adopt the principle of nuclear fusion, and that's all.

From atomic bombs to hydrogen bombs, superpowers such as the United States and the Soviet Union need a long time. The main reason is that the technical route is unknown and the calculation is complicated. Although klaus fox, a British scientist, first put forward the idea of radiation implosion to compress thermonuclear charge in 1948, this idea was rediscovered by Americans in 195 1 year, which is the core element of the famous Teller-Ulam configuration of hydrogen bombs. The Soviet Union didn't realize the key factors of radiation implosion until 1954, and successfully detonated the radiation implosion hydrogen bomb on1955+065438+1October 22nd. In addition, it needs to be pointed out that the hydrogen bomb exploded on August 2, 1953 in the Soviet Union 1953 adopted a "thousand-layer cake" configuration, which was not so much a hydrogen bomb as an enhanced atomic bomb. If this RDS-6S is considered as a hydrogen bomb, then the United States successfully exploded this enhanced atomic bomb containing fusion thermonuclear materials as early as 195 1, and the successful time of China's first hydrogen bomb can also be considered as 1966.

The development of China's hydrogen bomb began before the first atomic bomb exploded. At the end of 1960, under the leadership of Qian Sanqiang, China began to explore the theory of hydrogen bomb, and set up a "light nuclear reaction device theory exploration group" in the Institute of Atomic Energy, which was headed by Cai, Liu Xianhui and Sabenhao, and was later joined by He Xiuxiu. In order to strengthen the research strength of the light nuclear theory group, Huang Zuqia, the group leader, repeatedly suggested to Qian Sanqiang that Yu Min, a theoretical expert, be transferred. 196 1 year 1 month 12 After an interview with Qian Sanqiang, Yu Min joined the light nuclear theory group as the deputy head.

At that time, there were only eleven or twelve people in the whole group, and the focus of China's nuclear weapons research at that time was to break through the atomic bomb. 95% of the workload of the only domestic electron tube computer is also used for theoretical calculation of atomic bombs. Huang Zuqia, the company leader, mainly studied atomic bombs, and Yu Min undertook the main research and organization work of the light nuclear theory group. Because electronic computers are mainly used in the development of atomic bombs, Yu Min and his team members have to use the slide rule to calculate, and have solved a lot of basic theoretical problems in their work for several years. Yu Min, with his extraordinary physical intuition, can sort out the clues and find the key in the complicated phenomena and data. Yu Min has made the most important contribution to many key issues in the development of hydrogen bombs, and is a well-deserved "father of hydrogen bombs" in China.

1964 After the successful explosion of the first atomic bomb in China, the engineering development of hydrogen bombs was quickly put on the agenda at the beginning of 1965, with the code "1 100", which means 1 ton and 1 10,000 ton equivalent hydrogen bombs. But the research of hydrogen bomb is complicated after all. Although China had already broken through the principle of explosive-boosting and energy-boosting atomic bomb as early as 1963, the principle of hydrogen bomb didn't make a key breakthrough until 1965. Therefore, it is necessary to explode one or more atomic bombs in a planned way, and enhance the understanding of thermonuclear fusion according to the test feedback.

1965 10 In the process of making an academic report, Yu Min clarified his thinking and decided that increasing the density of thermonuclear fusion materials is the key to the development of hydrogen bombs. It is not enough to increase the density by explosives, but only by atomic energy. After several days of analysis and thinking, he came up with an ingenious design structure to reduce the energy loss of atomic bomb explosion and improve the utilization rate of compressed energy, and further proposed two models. 165438+1At the beginning of October, Yu Min and others verified the correctness of the theoretical model through calculation. The basic idea of the principle of hydrogen bomb put forward by Yu Min and others is to maintain the condition of self-sustaining fusion of thermonuclear materials with atomic bombs. For this reason, the hydrogen bomb includes primary and secondary parts. The initiation part of the atomic bomb is called primary, trigger or initiation stage, and the part where the thermonuclear material changes greatly is called secondary, trigger or hydrogen bomb body.

Since then, the development of hydrogen bombs in China has embarked on the fast track. 1On May 9th, 966, China's first enhanced atomic bomb exploded successfully, which provided measured data for the theoretical study of hydrogen bombs and improved the design of hydrogen bomb triggers. At the end of 1966, China's first hydrogen bomb nuclear trigger was frozen and entered the manufacturing stage. 1966165438+1October 28th, the principle test of hydrogen bomb was carried out in China, and the explosion equivalent was122,000 tons of TNT. In fact, it is a successful hydrogen bomb test in terms of principle, material and configuration, but it is only a verification test of the principle of hydrogen bomb, not the first officially prepared hydrogen bomb, and its explosive equivalent is also particularly limited. 1On June 7th, 1967, China completed the explosion of the first hydrogen bomb by air-dropping with Tu 16 bomber, with an explosion equivalent of 3.3 million tons, marking the final success of the "1 100" project.

Third, the combination test of two bombs and the practical use of nuclear weapons.

Both the first atomic bomb and the first hydrogen bomb in China have huge quality problems, and their actual deterrent ability is very limited. After China's first atomic bomb exploded successfully, it was dubbed "a bullet without a gun" by the western media. In order to realize the actual combat of nuclear weapons as soon as possible, China has also made great efforts, and the speed and results are equally amazing.

1965 just after the spring festival, the party central Committee and the central military commission issued the task of airdropping atomic bombs. Because of the huge mass of the atomic bomb, only Tu 16 bombers could be used at that time. On February 18, the Fourth Independent Regiment of the Air Force entered the Northwest Airport and began to use cement training bombs instead of atomic bombs for airdrop tests. According to the requirements, the dropped atomic bomb must break through the 100 meter mark, and in the last airdrop in the first month of training, the crew unexpectedly reached the accuracy of 35 meters. Later, although there was a problem of bullet leakage, the unit still found the reason for the deviation and solved the problem. In April, the airdrop test reached an accuracy of 96 meters. 14 In May, 16 troops carried an airdropped circular atomic bomb and successfully airdropped it at 9: 59 am. Radar measurements show that the atomic bomb is only 40 meters away from the bull's-eye, successfully completing the first atomic bomb airdrop test in China.

Figure 16 The penetration ability of air-dropped atomic bombs is not strong, and the deterrent ability is also insufficient. Nuclear ballistic missiles still have sufficient deterrent capability today, and the nuclear deterrence of major nuclear powers is based on nuclear ballistic missiles. Surprisingly, however, due to security considerations, there are few actual nuclear missile tests. In most countries, missiles and nuclear bombs are tested separately. There are only two flight tests of ballistic missiles loaded with real nuclear warheads, one of which is China's "two-bomb joint test".

196610/kloc-0 On October 27th, China conducted a famous ballistic missile-atomic bomb combination test at Jiuquan Satellite Launch Center. This test is also the most confidential of China's previous nuclear tests. China launched a nuclear warhead from Jiuquan Launch Center using Dongfeng-2 medium-range ballistic missile, aiming at Lop Nur proving ground in Xinjiang. The combination test of two bombs carries a real nuclear warhead. Although the whole flight is not too far, it is all over China, and the test pressure is great. In order to carry out the experiment of combining two bombs, the Lanzhou-Xinjiang railway was stopped, and millions of residents in Hexi Corridor along the missile flight were evacuated urgently, while only seven people were left in the launching position of Jiuquan Launch Center. The missile was successfully launched at 9 am. After 9 minutes of various flights, the warhead of the atomic bomb exploded accurately over the target of Lop Nur, and the combination test of two bombs in China achieved unprecedented success.

The combination test of the two bombs not only effectively countered the ridicule of "bullets without guns" abroad, but also expressed China's firm determination to use nuclear weapons to defend national security in the harsh international environment in the 1960s. At that time, news came out from time to time in the western media that the Soviet Union secretly invited the United States to carry out a nuclear strike against China's nuclear weapons development base.

After the successful explosion of the first hydrogen bomb in China, the practical application of the hydrogen bomb also made a rapid breakthrough. Although Dongfeng 2A still uses atomic bomb warheads, Dongfeng III medium-range ballistic missiles plan to use new hydrogen bomb warheads. From 1969 to 1970, China conducted Dongfeng III's "two-bomb combined cold test", that is, inert materials were used to replace the primary fissile materials of hydrogen bombs, which could simulate the reentry and an explosion of missiles carrying hydrogen bombs. The success of the test shows that Dongfeng-3 missile has combat capability. The successful development of a million-ton equivalent hydrogen bomb warhead and a Dongfeng -3 missile with a range of 2,500 kilometers has greatly improved the strike range and deterrent capability of China's Second Artillery Corps, and is a symbol of China's actual combat capability of hydrogen bombs.

Fourth, warhead miniaturization technology is close to the most advanced level in the United States.

According to the data in China Military Encyclopedia, the mass of China's first atomic bomb is 1550kg, while the mass of Dongfeng-2 missile's nuclear warhead is estimated to be 500kg. As for a certain type of hydrogen bomb warhead, it weighs more than 2 tons, which means that only a large bomber like Tu 16/ H-6 or a large ballistic missile can throw such a nuclear warhead. As large-scale long-range intercontinental missiles, Dongfeng IV and Dongfeng V have no problem in throwing large-equivalent thermonuclear warheads, but the first-generation submarine-launched ballistic missile Julang-1, which is being developed in China, is really helpless. With the development of Julang-1, the miniaturization of China's nuclear weapons was also put on the agenda in 1970s, and brilliant achievements were made one after another.

China's second-generation strategic missile's second-generation nuclear warhead adopts advanced gas-assisted initiation technology. According to the above, the hydrogen bomb actually includes an atomic bomb trigger. The equivalent of this atomic bomb is generally thousands or even tens of thousands of tons, and its natural mass is very large. The key to miniaturization of hydrogen bomb is miniaturization of primary stage. In the primary stage of modern hydrogen bomb, the method of boosting the atomic bomb is adopted, and a small amount of fusion materials are added to boost the explosion. There are two kinds of explosion assistance: solid explosion assistance and gas explosion assistance. China's first generation hydrogen bomb, such as Dongfeng V, was assisted by solid explosion, and American intelligence agencies speculated that its mass reached 3 tons. 1September 26th, 976, the first-class explosion test of solid booster in China was successful, and the full equivalent explosion test of Dongfeng V hydrogen bomb warhead was successful in the same year1October 26th17. This nuclear test with an equivalent of 5 million tons is also the largest in China. The warhead of China Julang-1 missile also uses solid booster, but its explosive equivalent is low because its mass is less than 1 ton. On this basis, China carried out research on miniaturization of nuclear warheads, and the second generation of nuclear warheads adopted gas-assisted detonation technology, which further reduced the volume and mass of nuclear warheads.

Under the shadow of the United States and the Soviet Union's nuclear weapons design approaching the limit and actively promoting a comprehensive ban on nuclear tests, Deng Jiaxian and other two fathers of bombs drafted a report in 1986, which was approved by the central authorities and decided to accelerate the development of nuclear weapons before the pressure from the international community increased.

In 1980s and 1990s, China developed an aspheric gas booster primary, which can minimize the mass of the conical warhead of intercontinental missiles. According to the report of Danny steelman and Cox, director of technical information department of Los Alamos National Laboratory, the primary design level of non-spherical gas-assisted detonation in China is very high, which is close to the level of the most advanced W88 nuclear warhead in the United States. This is also an "important basis" for the Cox Report thrown by the United States from 65438 to 0999 accusing China of stealing American technology.

The Cox Report also holds that China stole the neutron bomb technology. In fact, China successfully conducted the explosion test of neutron bomb in 1980s. After the Cox Report was published, the press office in the State Council, China said that China had mastered the technology of neutron bomb. According to the later reports of the official media, China conducted the first principle test of neutron bomb on February 1984 19, and finally completed the neutron bomb test on September 29th 1988.

5. The overall cost-effectiveness ratio of nuclear testing in China is the highest.

In the development of China's nuclear weapons, there is another detail that may be less noticeable, that is, China has the least number of nuclear tests among the five nuclear powers. By the end of May, 1998, the United States had conducted 1032 nuclear tests, the Soviet Union and Russia had conducted 7 15 nuclear tests, France had conducted 2 10 nuclear tests, Britain had conducted 45 nuclear tests, and China had only conducted 45 nuclear tests. Considering that Britain's nuclear weapons were completely dependent on the United States, China's nuclear test had the highest cost-effectiveness ratio.

China's 45 nuclear tests, including 23 above-ground nuclear tests and 22 underground nuclear tests. According to Danny Stillman, although China has not acceded to the Partial Nuclear Test Ban Treaty, China has been trying its best to reduce the radioactive dust from all previous ground nuclear tests. 1980 65438+1October 16 After the last atmospheric core test, China completely turned to underground nuclear testing. At this time, China has completed the development of the first generation of nuclear weapons from the first atomic bomb to the first hydrogen bomb, and from Dongfeng II missile to Dongfeng V missile through more than 20 nuclear tests. Since 1980s, China has broken through the key technology of miniaturization of nuclear warheads with less than 20 nuclear tests, and reached the world advanced level in the core technology of nuclear weapon design, thus ensuring the effectiveness and reliability of China's nuclear deterrent force after the signing of the Comprehensive Nuclear-Test-Ban Treaty.

On the other hand, the least number of nuclear tests in China has also brought some hidden worries. The development of China's nuclear weapons is the slowest in the middle and late period, and its nuclear weapons technology not only lags far behind the United States and the Soviet Union, but also quickly catches up with the French, which shows that China is the latest country to break through the miniaturization technology of nuclear weapons, and also the latest country to develop the multi-warhead technology with split guidance. In the hundreds of nuclear tests conducted by the United States and the Soviet Union, the main purpose is to meet the development of various nuclear warheads from tactical nuclear weapons to strategic nuclear weapons, including several tons of large-equivalent nuclear warheads from one million tons to ten million tons, as well as several kilograms of nuclear shells or nuclear air-to-air rockets. A large number of nuclear tests conducted by the United States and the Soviet Union are also used to find out the "limit" of nuclear weapons design. These test data are very important for computer simulation nuclear tests in the future.

However, China's limited nuclear tests are mainly used to develop a few strategic missile nuclear warheads, and computer simulation of nuclear tests may lack sufficient data. Another problem is that the older generation of scientists who have participated in nuclear tests may lack the experience and ability to design new nuclear warheads when they get old. Of course, even the United States, after signing the Comprehensive Nuclear-Test-Ban Treaty, found that computer simulation could not replace the actual nuclear test, and there was a lack of young people who could develop new nuclear warheads. The problems existing in China are also faced by other countries.

After the signing of the Comprehensive Nuclear-Test-Ban Treaty, countries such as the United States and Russia began to conduct subcritical tests. There was no actual nuclear explosion in this nuclear test, so the treaty banning nuclear tests was circumvented. In addition, major nuclear powers have developed various nuclear test simulators, such as national ignition facility in the United States, Shen Guang in China and other laser nuclear fusion research devices. The United States has also set up a Z device specially used for nuclear weapons research in the San Diego laboratory, and the Julong-1 device, which just passed the appraisal of China No.9 Hospital last year, has the same purpose. On the road of developing nuclear weapons in the future, scientists in China are still forging ahead courageously.