After the British scientist Faraday discovered the phenomenon of electromagnetic induction in 1831, military experts from various countries were deeply inspired and immediately considered using the principle of electromagnetic force to launch objects to create weapons. In 1845, British physicist Chars Wheastone built the world's first linear reluctance motor and used it to throw a metal rod 20m away. In 1895, Mayor of Pittsburgh, USA, obtained the first linear induction motor patent. But linear motors and electric guns are still far from each other. The first person to clearly propose the concept of electromagnetic gun and to persist in long-term experiments was a Norwegian scientist, Kristian Birkeland, professor of physics at the University of Oslo (Aslo). From 1897 to 1917, Professor Birkeland continued to improve and test the electric gun he invented, and obtained three electric gun technology patents from 1901 to 1903. In 1901, he made the first electromagnetic coil gun and used it to accelerate a 0.5kg shell to 50m/s; the second coilgun made in 1903 accelerated a 10kg object to 100m/s. speed. This was a remarkable achievement at the time.
In 1912, Emile Bachelet of France built the first AC-excited magnetic propulsion device. In 1920, France's Fauchon-Villeple`e published the article "Electric Artillery". At almost the same time, the Electric Gun Company in Philadelphia, USA, developed an electromagnetic accelerator for artillery. Before World War II, there were as many as 45 patents on various electric guns.
At the end of World War II, the German military continued to search for and actively develop various new weapons with Hitler's approval, and electromagnetic guns were one of them. In 1944, Dr. Asim Hansler and Chief Inspector Bonzel tested a 10mm coil gun at the training ground in Magdeburg, but the test failed. Later, Hansler conducted many electromagnetic gun tests, mainly rail guns, and I will not elaborate further here. With Germany's defeat, Dr. Hansler's research work was suspended.
In 1946, the American Westinghouse Electric Company built a full-scale aircraft ejection device called the "electric drag", which was a primary motion linear induction motor. Then the U.S. Navy and Air Force also did some research work. However, after repeated demonstrations, the Air Force Scientific Research Institute concluded in 1957 that "electromagnetic launch is simply not feasible", which put the research on electromagnetic launchers into trouble.
However, a large number of electromagnetic gun tests were conducted in the Soviet Union in 1958 and 1965. In 1966, Professor Winterberg of the University of Nevada in the United States proposed the concept of using magnetic traveling waves to accelerate superconductors. In 1966, the Soviet Union's Bostalev used a 1cm-long single-stage pulse induction coil transmitter to accelerate a 2g aluminum ring to 5km/s. In 1972, NASA proposed a brush-commutated spiral coilgun, while MIT developed the first coilgun similar to a synchronous DC motor.