Zero-dimensional simulations of wire array experiments and Z-pinch flux compression using the SPEED2 generator

Zero-dimensional simulations are used to gain an insight into the optimal setup for which the best energy transfer efficiency between the generator and the load system, and high currents at the moment of pinch are expected in wire array experiments using the SPEED2 generator. The generator is characterized by 4.1 μF equivalent Marx generator capacity, 300 kV maximum charge voltage, 187 kJ and 4 MA maximum current in short circuit at maximum charge voltage, 400 ns first quarter of period and dI/dt∼10¹³ A s⁻¹. The model used in the simulations describes the dynamics of the current sheet coupled to the dynamics of the electric circuit. In order to have a better understanding of the generator behaviour when magnetic flux compression experiments using wire arrays are driven in SPEED2, the presence of an external axial magnetic field has also been considered. Based on the simulations results, a load design criteria for wire arrays experiments in SPEED2 is presented . The procedure to find a load design criterion presented here, is quite general and could be applied to experiments such as wire arrays or gas puff Z-pinches when these are driven by using low impedance capacitive generators.