In addition, railguns usually require the use of sliding contacts to pass a large current through the projectile or sabot, but coilguns do not necessarily require sliding contacts. Coilguns are distinct from railguns, as the direction of acceleration in a railgun is at right angles to the central axis of the current loop formed by the conducting rails. The coils are switched on and off in a precisely timed sequence, causing the projectile to be accelerated quickly along the barrel via magnetic forces. The name 'Gauss' is in reference to Carl Friedrich Gauss, who formulated mathematical descriptions of the magnetic effect used by magnetic accelerator cannons.Ĭoilguns generally consist of one or more coils arranged along a barrel, so the path of the accelerating projectile lies along the central axis of the coils. A coilgun is not a rifle as the barrel is smoothbore (not rifled). In almost all coilgun configurations, the coils and the gun barrel are arranged on a common axis. Simplified diagram of a multistage coilgun with three coils, a barrel, and a ferromagnetic projectileĪ coilgun, also known as a Gauss rifle, is a type of mass driver consisting of one or more coils used as electromagnets in the configuration of a linear motor that accelerate a ferromagnetic or conducting projectile to high velocity.