Progress on the Godzilla gigawatt MPD plasma accelerator and nozzle for fusion propulsion simulations

Extensive human exploration and development of space requires propulsion systems that can provide both high thrust-to-weight ratio and high specific impulse. Fusion propulsion is one of the enabling technologies considered for application in such missions. A critical and common element to many fusion propulsion concepts is the expansion of the fusion-grade plasma through a magnetic nozzle. Efforts to evaluate this essential component of a fusion propulsion system began a few years ago at The Ohio State University as part of a project sponsored by the NASA Glenn Research Center. The university houses Godzilla, a gigawatt-level, 1.8- megajoule pulseline that can power an acceleration system consisting (primarily) of a magnetoplasmadynamic (MPD) source and two magnet coils. The MPD source is designed to deliver hypersonic plasma flow to a magnetic-diffuser section for compression to a nearly stagnant state after passage through the converging-diverging guide field. The stagnated plasma will then be accelerated to supersonic speeds through a second magnet coil. The full effort encompasses both computational and experimental approaches to this device.