Preheating ablation effects on the Rayleigh-Taylor instability in the weakly nonlinear regime

Journal Article · Wed Dec 15 04:00:00 EST 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3517606· OSTI ID:21532099

Wang, L F ^[1]; Ye, W H; He, X T ^[2]; Sheng, Z M ^[3]; Don, Wai-Sun ^[4]; Li, Y J ^[1]

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1. SMCE, China University of Mining and Technology, Beijing 100083 (China)
2. CAPT, Peking University, Beijing 100871 (China) and LCP, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
3. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)
4. Department of Mathematics, Hong Kong Baptist University, Kowloon Tong (Hong Kong)

The two-dimensional Rayleigh-Taylor instability (RTI) with and without thermal conduction is investigated by numerical simulation in the weakly nonlinear regime. A preheat model {kappa}(T)={kappa}{sub SH}[1+f(T)] is introduced for the thermal conduction [W. H. Ye, W. Y. Zhang, and X. T. He, Phys. Rev. E 65, 057401 (2002)], where {kappa}{sub SH} is the Spitzer-Haerm electron thermal conductivity coefficient and f(T) models the preheating tongue effect in the cold plasma ahead of the ablation front. The preheating ablation effects on the RTI are studied by comparing the RTI with and without thermal conduction with identical density profile relevant to inertial confinement fusion experiments. It is found that the ablation effects strongly influence the mode coupling process, especially with short perturbation wavelength. Overall, the ablation effects stabilize the RTI. First, the linear growth rate is reduced, especially for short perturbation wavelengths and a cutoff wavelength is observed in simulations. Second, the second harmonic generation is reduced for short perturbation wavelengths. Third, the third-order negative feedback to the fundamental mode is strengthened, which plays a stabilization role. Finally, on the contrary, the ablation effects increase the generation of the third harmonic when the perturbation wavelengths are long. Our simulation results indicate that, in the weakly nonlinear regime, the ablation effects are weakened as the perturbation wavelength is increased. Numerical results obtained are in general agreement with the recent weakly nonlinear theories as proposed in [J. Sanz, J. Ramirez, R. Ramis et al., Phys. Rev. Lett. 89, 195002 (2002); J. Garnier, P.-A. Raviart, C. Cherfils-Clerouin et al., Phys. Rev. Lett. 90, 185003 (2003)].

• OSTI ID: 21532099
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABLATION
COLD PLASMA
COMPUTERIZED SIMULATION
CONFINEMENT
DISTURBANCES
ENERGY TRANSFER
FREQUENCY MIXING
HARMONIC GENERATION
HEAT TRANSFER
INERTIAL CONFINEMENT
INSTABILITY
PHYSICAL PROPERTIES
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA SIMULATION
RAYLEIGH-TAYLOR INSTABILITY
SIMULATION
THERMAL CONDUCTION
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TWO-DIMENSIONAL CALCULATIONS
WAVELENGTHS