Plasma Injector Development and Free-Running Arc Experiments for a 7 km/s Plasma-Driven Railgun

The objective of the Institute for Advanced Technology IAT effort is to demonstrate 7 kms with a plasma-driven railgun. Our principal challenge is to manage restrike arcs, which in past experiments have limited muzzle speeds to between 5 and 6 kms. Restrike arcs are a consequence of ablation of the bore insulators. Our approach is to eliminate bore ablation by using 1. high-purity alumina insulators to raise the ablation resistance of the bore, 2. pre-acceleration to prevent ablation of the bore materials at low velocity, and 3. magnetic augmentation to reduce power dissipation in the plasma. Each of these measures requires a dedicated hardware subsystem. In 2006, we designed and built the three subsystems and successfully tested the first two.