Numerical analysis of hydrodynamic instability in magnetized laser ablation flow

Abstract

We have conducted radiation magneto-hydrodynamics (RMHD) simulations of Richtmyer–Meshkov instability (RMI) in a magnetized counter flow produced by intense lasers. A jet-like plasma from a planar plastic target is formed and maintained in several-tens of nanoseconds by expanding plasma from rear side of two separated laser spots, and parallelly located another target is ablated by the radiation from the plasma, reproducing past experimental works. A planar shock driven by the radiation interacts with the jet as a nonuniform density structure, resulting in the RMI. The magnetic field is amplified up to ∼40 times greater than the background value at the interface at which the instability occurs. However, a certain extent of the amplification results from the compression effect induced by the counter flow, and the obtained amplification level is difficult to be measured in the experiments. An experiment for observing a clear amplification must be designed through the RMHD simulations so that the RMI takes place in the low-density area between two targets.