Self-generated magnetic field in three-dimensional ablative Rayleigh-Taylor instability

TL;DR

This study investigates the generation and effects of magnetic fields in three-dimensional ablative Rayleigh-Taylor instabilities during inertial confinement fusion, revealing stronger fields and different growth dynamics compared to 2D models.

Contribution

It demonstrates that 3D ARTI can generate stronger magnetic fields than 2D models and explores the impact of Nernst effects and magnetic fields on instability growth.

Findings

Magnetic fields up to thousands of Tesla can be generated in 3D ARTI.

Nernst effects significantly influence magnetic field convection and amplification.

Magnetic fields mainly accelerate spike growth in 3D ARTI, with little effect on bubble growth.

Abstract

The self-generated magnetic field in three-dimensional (3D) single-mode ablative Rayleigh-Taylor instabilities (ARTI) relevant to the acceleration phase of a direct-drive inertial confinement fusion (ICF) implosion is investigated. It is found that stronger magnetic fields up to a few thousands of T can be generated by 3D ARTI than by its two-dimensional (2D) counterpart. The Nernst effects significantly alter the magnetic fields convection and amplify the magnetic fields. The scaling law for the magnetic flux obtained in the 2D simulations performs reasonably well in the 3D cases. While the magnetic field significantly accelerates the bubble growth in the short-wavelength 2D modes through modifying the heat fluxes, the magnetic field mostly accelerates the spike growth but has little influence on the bubble growth in 3D ARTI.