Alpha (α) magnetic spectrometer was the first large-scale magnetic spectrometer sent into space in 1998. It uses strong magnetic fields and precision detectors to detect antimatter and dark matter in space, and explores and studies some important and difficult problems in cosmic physics, elementary particle physics and the evolution of the universe, such as finding magnetic monopoles. The earliest alpha magnetic spectrometer was sent into space by the space shuttle Discovery in 1998, and its test time was about 10 days. The picture shows the alpha magnetic spectrometer on the space shuttle Discovery, taken at the Mir space station. It is planned to send the Alpha Magnetic Spectrometer to the International Space Station in 2003 to work for 3-5 years to detect space antimatter and dark matter for a long time. The development of Alpha Magnetic Spectrometer (AMS) is a large-scale international cooperative scientific research project proposed and led by Professor Ding Zhaozhong, a Chinese-American physicist and Nobel Prize winner in physics (1976). 37 scientific research institutions in 10 countries and regions, including the United States and China, participated in the research work. Its main purpose is to find antimatter and dark matter in space and solve other major scientific problems. Antimatter refers to a substance composed of antielectrons (i.e. positrons), antiprotons and antineutrons with the same mass but opposite charge signs, such as anti-helium and anti-carbon. Dark matter refers to substances that cannot be detected by optical methods. According to some theories in modern scientific research, there should be antimatter in the universe besides normal matter (that is, positive matter); In addition to ordinary matter detected by optical methods, there should be dark matter that cannot be detected by optical methods. These substances will show different characteristics when moving in the magnetic field, so they can be detected by the detector. Alpha magnetic spectrometer is mainly composed of magnetic system and sensitive detector.
Chinese-American physicist Professor Ding Zhaozhong's ancestral home is Rizhao County, Shandong Province. Born in the United States because both parents are studying in the United States (1936). Shortly after returning to China, War of Resistance against Japanese Aggression broke out and spent his childhood in Sichuan with his parents. Then I went to Taiwan Province Province with my parents. From 65438 to 0956, study in the United States. He studied in engineering college first, and then transferred to physics department. After receiving his doctorate, he engaged in physics research. 1974, the experimental group led by him discovered the J particle. Two years later (1976), Professor Ding Zhaozhong won the Nobel Prize in physics for this important discovery. 1993 was initiated by professor Ding Zhaozhong, and invited scientists from the United States, China and other countries and regions to form the alpha magnetic spectrometer experimental group for international cooperation research. In the research of alpha magnetic spectrometer, Chinese scientists have completed the design, manufacture and installation of large-scale rare earth permanent magnet system (pictured).
It can be seen that α magnetic spectrometer is an important research and application achievement of contemporary cosmic magnetism. We in China have also made important contributions to this important research and application.
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Assembling Large Permanent Magnet for α Magnetic Spectrometer
A large permanent magnet for alpha magnetic spectrometer developed by Institute of Electrotechnics, Institute of High Energy Physics and China Academy of Launch Vehicle Technology was completed in Beijing. Alpha Magnetic Spectrometer (AMS) is the first magnetic spectrometer sent into space by human beings. It was built under the leadership of Ding Zhaozhong, a Chinese-American physicist and Nobel Prize winner, in cooperation with scientists from China, the United States, Germany, Switzerland, Italy and other countries. AMS can accurately measure the momentum and charge of charged particles in the universe. The core of AMS is a large permanent magnet made of NdFeB material developed by China, weighing 2.2 tons, with a diameter of 1.2m, a height of 0.8m and a central field strength of 1.360 gauss.
In the space experiment, the magnet of magnetic spectrometer is required to be very strict, which requires not only strong magnetic field, high reception and light weight, but also very small magnetic bias and magnetic dipole moment, which can withstand the acceleration and violent vibration of the space shuttle during takeoff and landing. In the past 20 years, European and American scientists have put forward various development plans, but they all failed. According to Professor Ding Zhaozhong's idea of manufacturing magnetic spectrometer with permanent magnet, the scientific and technical personnel of Institute of Electrotechnics and Institute of High Energy of Chinese Academy of Sciences creatively put forward the scheme of using NdFeB permanent magnet after a lot of analysis, calculation and simulation tests, and the mechanical structure of the magnet was designed and manufactured by China Academy of Launch Vehicle Technology. The magnet is made of a new type of NaFeB permanent magnet with high magnetic energy product. Based on the magic ring structure, it needs a lot of numerical calculation and high-tech synthesis to be used in space experiments, the design of magnets and transportation shielding systems and the measurement of magnetic fields. After the initial sample of AMS magnet was manufactured, 10 vibration and centrifugal tests were carried out to simulate the space environment. The test results show that the performance of the magnet fully meets the strict requirements of NASA.
Alpha magnetic spectrometer was sent into space by the American space shuttle Discovery on June 3rd, 1998, and antimatter and dark matter were detected there.
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