Coilgun

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1 Overview
2 Construction
3 Potential uses
4 Coilguns in science fiction
5 See also

A coilgun (also known as Gauss gun, Gauss cannon or Gauss rifle) is a type of magnetic accelerator gun (MAG) or magnetic accelerator cannon (MAC). It uses a series of electromagnetic coils to accelerate a magnetic shell to very high velocities. The name "Gauss gun" comes from Carl Friedrich Gauss, who formulated mathematical descriptions of the electromagnetic effect used by coilguns.

[edit] Overview

Coilguns are often mistakenly called railguns, and while they are similar in general concept (that is, a magnetic gun), they differ in operation, as a railgun accelerates projectiles down two parallel conducting rails. Coilguns are essentially identical to mass drivers, though on a smaller scale. Kristian Birkeland is commonly considered the inventor of the electromagnetic coilgun, for which he obtained a patent in 1900. The attempts to turn his invention into a usable weapon failed, and the idea was more or less forgotten for many years.

Many hobbyists use low-cost rudimentary designs to experiment with coilguns. One such design would incorporate the use of photoflash capacitors from a disposable camera as the energy source, and a low inductance coil to propel the projectile forward.

[edit] Construction

Image:Coilgun animation.gif

A coilgun, as the name implies, consists of a coil of wire (or solenoid) with a ferromagnetic projectile placed at one of its ends. A large current is pulsed through the coil and a strong magnetic field forms, pulling the projectile to the center of the coil. When the projectile nears this point, the coil is switched off and a next coil can be switched on, progressively accelerating the projectile down successive stages. In common coilgun designs, the "barrel" of the gun is made up of a track that the projectile rides on, with the driver coils around the track. Power is supplied to the coils from some sort of fast discharge storage device, typically a battery of high-capacity high voltage capacitors designed for fast energy discharge.

[edit] Potential uses

Like railguns and ram accelerators, coilguns have been proposed for use in delivering payloads to space.

As a weapon, the coilgun's advantages include the fact that it has no moving parts, apart from the projectile, and the fact that the only noise heard is the movement of the projectile when it reaches very high speeds. Though coilguns have been shown to reach supersonic speeds, the projectile moves slower than that used in a railgun.

The University of Texas at Austin Center for Electromechanics has been working on this [1] for years for the United States Department of Defense.

A superconducting quench gun could be created by successively quenching a line of adjacent coaxial superconducting coils forming a gun barrel, generating a wave of magnetic field gradient travelling at any desired speed. A travelling superconducting coil can be made to ride this wave like a surfboard. The device in fact represents a mass driver or linear synchronous motor in which the propulsion energy is stored directly in the drive coils.

[edit] Coilguns in science fiction

Coilguns are a popular device in science fiction, especially sci-fi role playing and video games, where they go under such names Gauss cannon, Gauss rifle, or Magnetic Accelerator Cannon . Examples are:-