Laser driven hydrodynamic instability experiments on Nova

Summary form only given, as follows. A series of experiments on hydrodynamic (Rayleigh-Taylor) instabilities seeded by drive modulations in planar foils has been performed on the Nova laser at Lawrence Livermore National Laboratory. A drive laser beam smoothed by a random phase plate and by spectral dispersion with variable bandwidth was used. The laser far-field image was measured both time integrated and time resolved. The samples (flat polyethylene foils 20 /spl mu/m thick and 700 /spl mu/m in diameter) are driven with /spl sim/1 /spl times/ 10/sup 14/ W/cm/sup 2/ of 0.53 /spl mu/m laser light for 3 ns. The targets are radiographed during acceleration using a multiple-frame gated X-ray pinhole camera (gate time /spl sim/100 ps). The X-ray backlighter target is uranium and is illuminated by a second laser beam. The time-resolved measurement of the laser far-field agrees quantitatively with modeling. Systematic behavior of the measured modulations in optical depth has been observed which agrees qualitatively with anticipated behavior.