Effect of Medium Inhomogeneity on Hydrodynamic Evolution

Experimental studies of hydrodynamic instabilities of interfaces related to inertial confinement fusion often utilize low-density foams. A detailed understanding of these instabilities necessitates an accurate knowledge of the materials in which they are evolving. Theoretical predictions and simulations of these instabilities often assume the foam to be a continuous solid medium. However, the foams are not a solid material; rather they are porous with cell sizes ranging from nanometers to microns. An experiment was performed on the OMEGA Laser to measure the temporal evolution of hydrodynamic jets in which the target material utilized foams with varying cell sizes. Snapshots of the jet's evolution were recorded with point-projection radiography at multiple times. Results and simulations of the experiment will be presented. This work is performed under the auspices of the U. S. DOE by Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.