Reduction of the ablative Rayleigh-Taylor growth rate with Gaussian picket pulses

The effect of a Gaussian prepulse (picket pulse) before a drive pulse on the Rayleigh-Taylor (RT) instability growth rate was measured for single-mode, 20-, 30-, and 60-mum-wavelength mass perturbations. These data, from the OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] laser system, show that the measured RT growth of mass perturbations was reduced when a picket pulse was used. The picket pulse and subsequent relaxation period, before the drive pulse, cause the foil to expand and rarefy, resulting in higher ablation velocities during the drive pulse and greater ablative stabilization. This effect was examined both computationally and experimentally for different picket-pulse intensities. (C) 2004 American Institute of Physics.