Advancements in the development of a plasma-driven electromagnetic launcher

The Institute for Advanced Technology (IAT) is developing a plasma-driven railgun to launch low-mass projectiles of 5-10 g to a velocity in excess of 7 km/s. Accomplishing this goal requires overcoming the problem of bore ablation, which has been linked to an observed velocity ceiling of about 6 km/s in plasma-armature launchers. Bore ablation is a direct consequence of the intense heat radiated by plasma armatures. Controlling bore ablation requires a coordinated approach that includes magnetic augmentation to reduce power dissipation in the plasma, high-purity alumina insulators to raise the ablation resistance of the bore, and pre-acceleration to prevent ablation of the bore materials at low velocity. This paper describes the consequences of excessive bore ablation, the rationale for the IAT experiment, and results obtained from the hardware that has been designed and tested to date. Index Terms--Electromagnetic launch, hypervelocity, plasma, railgun.