The design of a pulse forming network for blocked-bore plasma armature railgun experiments

The railgun diagnostic program required a ramping current waveform with a continuously positive di/dt until peak current is delivered approximately 1 ms after circuit closure. This pulse forming network (PFN) was designed to power blocked-bore plasma armature studies being conducted on a section of the THUNDERBOLT, prototype, SUVAC. The PFN design has an operating voltage range from 300 to 1400 volts and is capable of delivering peak currents up to 200 kA to the railgun load.;A previous PFN made from 800 electrolytic capacitors was limited to less than a 100 kA square current pulse for the 1 ms shot duration. Budget constraints dictated that the former PFN be redesigned for higher current levels with a continuously positive di/dt before peak current to reduce arc lengthening. Thus, the overall objective is to design a PFN from the available 800 capacitors which delivers a maximized peak current that occurs near 1 ms and has a continuously positive di/dt until peak current occurs.