Exploring the Landau-Darrieus instability in High Energy Density conditions: Analytical model and FLASH simulations

Recent experimental work has been presented [Direct Drive Fast Ignition Workshop, T.Goudal] which was designed to observe the Landau-Darrieus Instability (LDI) for the first time in the context of laser-driven ablation fronts^1,2,3. The most recent experiments were conducted at the National Ignition Facility (NIF) and build upon previous work conducted at OMEGA EP. In order to design future experiments and build a reliable tool to be compared with experimental results, a coherent analytical model^4,5 has been developed to describe the hydrodynamic system within the conduction zone. Under certain assumptions, this model enables the study of the linear stability of the system and highlights the effect of LDI at the ablation front. To avoid stabilizing the LDI, the conduction zone length D_c must be smaller than the studied wavelength. To compare to and benchmark this model, 1D/2D FLASH simulations have been performed to study the instability’s behavior at the ablation front.

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² F. García-Rubio et al., Physics of Plasmas 27, 112715 (2020)

³ J. Sanz et al., Physics of Plasmas 13, 102702 (2006)

⁴ P. Clavin and L. Masse, Physics of Plasmas 11, 690 (2004)

⁵ H.J. Kull et al., Physics of Fluids 29, 2067 (1986)