The coil gun is a form of electric motor that works by having a conducting armature that either has a driven or induce current that is accelerated by force generated from the interaction of large magnetic fields created by surrounding coils. Several versions of the coil gun have been developed over the past fifty years. The versions developed include synchronous, induction, and superconductor quench. A particularly interesting version are the induction launchers. They are interesting for high speed applications for the reason that all the current in the armature is obtained by induction without sliding electrical contacts. When such contacts degrade they can significantly limit barrel lifetime due to the erosion of the surface caused by the high current that must be commutated across the contacts or gouging caused by the sliding of the contact conductor materials at high speed under pressure to maintain electrical continuity.
While at present coil guns do not have any industrial applications, there have been suggestions to use these systems to launch payloads into orbit. As attractive as the proposition sounds, numerous technical challenges need to be resolved before this is considered as a feasible project. A more realistic utilization may be launch boosting by giving a vehicle an initial speed by use of a long coil gun accelerator. The vehicle, after leaving the coil, would fire its rockets to achieve orbit. Believe it or not but launch boosting could actually result in significant savings in fuel costs.
The scientific fiction like concept of electromagnetic guns has actually been around for a while . On the month of June, year 1932, the Modern Mechanics magazine had a cover story that featured an electric cannon built by an English designer named Dr. Kapitza. This unique story told that the firing of the cannons shells was accomplished by short-circuiting powerful dynamos for periods of 1/100th of a second. In November 1936, a particularly interesting story was printed in that month’s issue of Popular Science about an electric machine gun. Virgil Rigsby of San Augustine, Texas built the gun and Virgil was also featured earlier in a 1934 issue of Modern Mechanix. It was claimed that the gun could fire 150 rounds per minute with the use of a series of electromagnets positioned along the barrel.
In Austin, Texas, physicists from the University of Texas at Austin, have reported that an atomic coil gun that slows and stops atoms has been developed. Dr. Mark Raizen and his colleagues used this new coil gun to slow neon atoms, and Raizen said coil gun could also be used with a variety of atoms. The coil gun functions by shooting a supersonic beam of atoms through a set of 18 magnetic coils. By making the atoms climb a “magnetic hill”, the coils are able to slow the atoms down. Before the atoms roll off the hill and regain speed, it is removed. Raizen’s main plan for the coil gun is to trap atomic hydrogen, which he says has been the Rosetta Stone of physics for many years and is the most abundant and simplest atom on the periodic table.
From a point of view like the military’s, coil gun technology could have a place in combat vehicles in the future, where, for example, it could form a part of the so-called “active electromagnetic armor” system. Hyper-velocity launching remains in the domain of the railgun, where there is a great deal of ongoing research. The coil gun has two distinctive types. The first type is the reluctance coil gun and this generates an acceleration by using the attractive ferromagnetic properties of the projectile. The second type is the induction coil gun where it’s accelerating force is repulsive and comes from the currents in the projectile when the coil has been fired. It may come as a surprise to learn that the coil gun is nothing new. The Norwegian scientist Kristian Olaf Birkland was actually a pioneer of a particular type of electromagnetic accelerator. Scottish physicist James Clerk Maxwell had equations that described magnetic and electrical forces and fields and during the 1890s Berkland presented solutions to these equations.
The coil gun has a thing called electromagnetic force which is a main thing that makes it work. But what is it? Electrically charged particles, such as protons and electrons, have a force present between them. This force is electromagnetic force. It has the ability to attract and repel charges. For charges that are like charges the electromagnetic force attracts and charges that are unlike it repels. Electromagnetic force is responsible for the binding of atoms. Electromagnetic force is like gravitational force in a sense that electromagnetic force acts over large distances and it does not need any medium. When compared gravitational force, electromagnetic force is very strong being 10^36 times stronger than gravitational force.