Comprehensive diagnosis of growth rates of the ablative Rayleigh-Taylor instability

• Published in: Physical review letters Vol. 98; no. 4; p. 045002
• Main Authors: Azechi, H, Sakaiya, T, Fujioka, S, Tamari, Y, Otani, K, Shigemori, K, Nakai, M, Shiraga, H, Miyanaga, N, Mima, K
• Format: Journal Article
• Language: English
• Published: United States 26-01-2007
• Subjects: ABLATION; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GRAVITATION; MASS; PERTURBATION THEORY; PLASMA DIAGNOSTICS; RAYLEIGH-TAYLOR INSTABILITY; SIMULATION; WAVELENGTHS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.98.045002

The growth rate of the ablative Rayleigh-Taylor instability is approximated by gamma = square root[kg/(1 + kL)] - beta km/rho(a), where k is the perturbation wave number, g the gravity, L the density scale length, m the mass ablation rate, and rho(a) the peak target density. The coefficient beta was evaluated for the first time by measuring all quantities of this formula except for L, which was taken from the simulation. Although the experimental value of beta = 1.2+/-0.7 at short perturbation wavelengths is in reasonably good agreement with the theoretical prediction of beta = 1.7, it is found to be larger than the prediction at long wavelengths.