|MLA Citation:||Bloomfield, Louis A. "Question 1107"|
How Everything Works 18 Jan 2018. 18 Jan 2018 <http://howeverythingworks.org/print1.php?QNum=1107>.
The rail gun's projectile must conduct electricity and it completes the electric circuit formed by two parallel metal rails and a high current power source. During the rail gun's operation, current flows out of the power source through one rail, passes through the projectile, and returns to the power source through the other rail. As it passes through the two rails, the electric current produces an intense magnetic field between the rails. The projectile is exposed to this magnetic field and as charged particles pass through the projectile, they experience a Lorentz force that pushes them and the projectile in one direction along the rails. The projectile picks up speed as it travels along the rails and doesn't stop accelerating until the current ceases or it leaves the rails. In practice, the power sources used in most rail guns is a large bank of capacitors. These devices store separated electric charge and supply enormous currents to the rails for a brief period of time.