railgun

Railgun is an electromagnetic projectile accelerator that uses a pair of parallel conductive rails and a sliding armature to accelerate a conductive projectile by the Lorentz force, producing high kinetic energy without relying on chemical propellants. When a large current is directed through one rail and travels through the armature to the other rail, a magnetic field forms between the rails. The interaction of the current and magnetic field exerts a force on the armature in the direction along the rails, rapidly accelerating the projectile as it travels to the muzzle.

Constructed devices typically consist of two parallel rails, an insulating frame to maintain a uniform gap, and an armature that electrically bridges the rails. The armature may be a metal contact that slides along the rails or a sabot-and-projectile arrangement with a conductive or plasma armature. Power is supplied by pulsed power systems capable of delivering multi-kilojoule bursts or megajoules in a few milliseconds.

Railguns have been explored for military and scientific use because they can achieve very high muzzle velocities and long range. Early research dates back to the late 19th and early 20th centuries, with renewed interest in the late 20th and early 21st centuries driven by advances in power storage and materials. Current challenges include extreme thermal and mechanical stresses on the rails, rapid wear, complex high-current power supplies, and efficiency losses. Despite progress, practical, fielded railguns remain largely in the research and development phase, with ongoing work aimed at improving durability, efficiency, and safety.