Railgun Energy Stores and Systems

Sufficient experimental railgun work and railgun analysis has now been performed to make it desirable to present an overview of what is offered by various options. These are examined. The single, pulsed homopolar generator inductor railgun system is well understood. It offers the means of imparting energies of multi-MJ to projectiles with masses of many kg. Hypersonic velocities can readily be obtained. When acceleration of masses in the gram range is required, the capacitor-inductor-railgun has advantages because switching is simpler. Capacitors make convenient energy stores in the sub-MJ range. If very high velocity is required, then the use of distributed energy stores is indicated because it overcomes limitations imposed by rail resistance, and enables the driving current to be kept up during projectile acceleration. Capacitor-based stores are, again, convenient for distributed energy store (DES) systems. If very high energies, in the GJ range, are required, then distributed homopolar energy stores will be appropriate. An application would be launching large masses from the earth's surface directly into space. When high repetition rates are required for a railgun system, average powers required may become so high that the direct use of chemical energy is desirable. A flux compressor consisting of an inverse railgun is suggested for this application. The performance of a compressor railgun system is analysed