Liner compression and instabilities and shocks at high currents with the Pegasus and Ranchero sources

We have done implosion experiments with cylindrical liners at currents ranging from 3 to 25 million amperes (MA). The low current (3-6 MA) experiments are done at the Pegasus capacitor bank facility and the high current (/spl sim/25 MA) ones are done with an explosive flux compression generator (Ranchero) in Ancho canyon at Los Alamos. Visible light and X-ray images provide details of the implosion but provide different results in both axial and radial views. Axial views taken with visible light framing cameras show that measurements of shock front velocity in imploding gas filled (Xe or Ar) aluminum liners appear to be different. Also, axial X-ray images give different shock velocities. Radial views show significant material "blow-off" as seen with the visible light framing camera. This paper discusses these differences and how they effect the hydrodynamics and instability growth in liner implosions. They also discuss the details of the diagnostic techniques that are necessary in this harsh experimental environment.