Planar indirect-drive Rayleigh-Taylor experiments on Nova
Abstract
A critical issue for laser-driven fusion is the extent to which surface perturbations grow during acceleration in high-gain implosion designs. To address this issue, an experimental and theoretical effort was initiated at the Nova Laser Facility to study perturbation growth due to the Rayleigh-Taylor instability on planar foils accelerated radiatively by a shaped drive. The growth of single-mode sinusoidal perturbations was measured in a set of experiments that varied separately the perturbation amplitude, wavelength, and foil thickness. To investigate mode coupling, foils were accelerated with two modes (wavelengths lambda(sub 1,2) = 50 micron, 75 micron) superposed on the surface. As a first attempt at determining the effect of a broad spectrum of modes, foils were recently accelerated whose surface perturbation is the superposition of eight modes (lambda(sub 1-8) = 22.5 to 180 micron) with random amplitudes. The experimental results and comparisons with 2-dimensional computer simulations will be presented.
- Publication:
-
Presented at the 21st Annual Anomalous Absorption Conference
- Pub Date:
- April 1991
- Bibcode:
- 1991anab.conf...15R
- Keywords:
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- Computerized Simulation;
- Coupled Modes;
- Implosions;
- Laser Plasmas;
- Perturbation;
- Taylor Instability;
- High Gain;
- Sine Waves;
- Spectra;
- Thickness;
- Plasma Physics