Laser shadowgraph measurements of electromagnetically-driven cylindrical shock-wave implosions in water

Experiments performed at the Los Alamos National Laboratory’s Atlas 23-MJ z-pinch capacitor bank facility allows for experimental characterization of electromagnetically-driven cylindrical shock-wave implosions. Time-resolved laser shadowgraphy is used to dynamically image an Atlas-generated liner–target radial shock implosion in water with two-dimensional imaging detail that provides benchmark results for numerical hydrocode validation efforts at Los Alamos. Our laser shadowgraph measurements capture eight separate image frames of shock-wave motion in the water, with overall spatial and temporal resolutions of ±0.25 mm and 10 ns, respectively. Imaging of the shock-wave radial shape and position inside the water volume allows for quantitative comparison with numerical simulations. A linear fit to the average radius one-dimensional shock-wave trajectory plot yields a shock speed in the water of 6.65 mm/μs, corresponding to a Mach-4 shock. Comparison of the measured shock-wave trajectory with the numerical hydrodynamic simulation codes is performed.