Pulse Discharge Network Development for a Heavy Gas Field Reversed Configuration Plasma Device

Abstract

A simple LRC circuit model is used to conduct a parametric study of the effects of charging voltage, capacitance, resistance, and inductance on the current waveform of a pulse forming network for field reversed configuration (FRC) plasma production. Using known waveforms from existing networks, estimates of realistic values of resistance and inductance are established for a base network model. Parametric modification of the base model is used to study the effects of each component of the discharge network. Results indicate that increasing charging voltage causes an increase in peak current, but does not effect rise or reversal times. However, increasing capacitance increases peak current and increases rise and reversal times. Further, optimum circuit parameters are determined for the design and construction of an FRC formation test article. Three main design criteria are used and are based on magnetic diffusion time, auto-ionization of background gas, and peak magnetic field strength. Results indicate that a pulse forming network with charging voltage of 25 kV and capacitance of 1 μF provides the widest range of resistance and inductance values such that the waveform meets the design criteria. Nomenclature