Planar Shock Wave Propagation in Multi-Species Gas with a 200-kA Pulsed Power Driver*

Shock waves in multi-species gases are relevant in a variety of topics in high energy density physics including astrophysical plasma physics and inertial confinement fusion (ICF) especially in liner-on-target implosion schemes. Results from planar foil shock experiments on a 200-kA pulsed power driver, GenASIS, are presented. In this experimental setup, a 5×5 mm² foil load of 1-10 μm thickness is heated and ablated by a high current pulse. The material is then accelerated normal to the foil plane via a magnetic pressure gradient set up by the anode-cathode gap. The characteristics of foil expansion and motion are initially studied by diagnosing the accelerating material in vacuum to determine the effect of foil load parameters on performance. Ablated material motion, as well as shock velocity, is determined using a four-frame schlieren imaging system with 30 ns inter-frame delay on an Nd:YAG laser. The relative motion of gas species is measured using spatially resolved visible spectroscopy coupled to a two-frame gated ICCD camera with 1 μs inter-frame interval.