3D MHD simulations of single and nested wire arrays constrained by experimentally measured mass distributions

Abstract

We present 3D resistive MHD modeling of the implosion and stagnation of single and nested wire array Z-pinches on the Z generator. Compact tungsten wire array Z-pinches have proven to be a powerful, reproducible X-ray source. The use of nested wire arrays has provided further gains in X-ray power and the pulse shaping capability necessary for application to inertial confinement fusion. Radiography of the imploding arrays has given us detailed measurements of their mass distributions, which when combined with electrical measurements and the measured X-ray pulse can be used to tightly constrain simulation results. We demonstrate good agreement between simulation and observation for 1.1 mg, 2.5 mg and 6 mg single arrays of a 20 mm diameter mass scan. We then use this model to describe the interaction and subsequent implosion of nested wire arrays, detailing possible processes responsible for narrowing of the imploding mass distribution, resulting in X-ray pulse compression.