Accession Number : ADA185945

Title :   The Rayleigh-Taylor Instability in Ablatively Accelerated Targets with 1, 1/2 and 1/4 Micrometers Laser Light.

Descriptive Note : Interim rept. 1 Oct 86-22 Sep 87,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Emery, Mark H ; Dahlburg, Jill P ; Gardner, John H

PDF Url : ADA185945

Report Date : 22 Sep 1987

Pagination or Media Count : 29

Abstract : The results of a series of detailed numerical simulations are presented for the Rayleigh-Taylor instability in laser ablatively accelerated targets for a fairly wide range of initial conditions. It is shown that the Rayleigh-Taylor growth rate in an ablative environment is a strong function of the laser wavelength. For perturbation wavelengths about 3 times the inflight target thickness, the ratios of the numerical growth rates to the classical growth rates are of the order of 1/1.5, 1/2.5 and 1/3.5 for 1, 1/2 and 1/4 micrometer laser light respectively. The numerical results are in good agreement with out theoretical based on the ablative convection of vorticity away from the unstable ablation front. These results provide strong evidence for the viability of high aspect ratio shells in direct drive laser fusion. Keywords: Laser ablation; Inertial confinement fusion; Hydrodynamic instabilities.

Descriptors :   *ABLATION, ABLATIVE MATERIALS, ASPECT RATIO, CONVECTION, GROWTH(GENERAL), HIGH RATE, INFLIGHT, LASER INDUCED FUSION, LASERS, NUMERICAL ANALYSIS, PERTURBATIONS, RANGE(EXTREMES), RATES, STABILITY, TARGETS, THICKNESS, LASER PUMPING, PLASMAS(PHYSICS)

Subject Categories : Plasma Physics and Magnetohydrodynamics
      Fusion Devices(thermonuclear)
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE