In direct-drive inertial confinement fusion (ICF) targets, the ablator-DT ice interface is generally not flat, but rippled. This rippled interface can feedout and form the perturbation seeds for the ablative Richtmyer-Meshkov and Rayleigh-Taylor (ARM/ART) instability, which has adverse effects on ICF. But the whole evolution of this rippled interface-initiated ART instability sill lacks detailed research. Besides, the high-Z dopant has been widely used in ICF target configuration because it can help diagnose and suppress the ARM/ART instability developed by external surface roughness, but the specific influence of high-Z dopant on the rippled interface-initiated ART instability is still unknown. In this article, we establish a simplified model to analyse the evolution of the rippled interface-initiated ART instability. Then the influence of high-Z dopant on this evolution is investigated through the 2D radiation hydrodynamic simulations. Compared to undoped targets with the same mass, the high-Z dopant target has smaller thickness, and larger ablation pressure during the feedout, both of which result in more severe velocity and interface perturbation. However, due to the significant inhibition of high-Z dopant on the ARM and ART instability, the perturbation in high-Z dopant target is still suppressed. But for long wave perturbations where high-Z dopant has weak suppression, the ART instability can be enhanced by the high-Z dopant. This indicates that for rippled interface-initiated ART instability, the high-Z dopant still can suppress except for the long wavelength perturbation. Above results may help comprehensively understand the effect of high-Z dopant on the hydrodynamic instability and provide meaningful guidance for optimizing the target designs in ICF research.

Ablative RT instability;High-Z dopant;Inner interface perturbation