Mass diffusion and liner material effect in a MagLIF fusion-like plasma

TL;DR

This study investigates how liner material properties affect mass diffusion, energy, and magnetic flux losses in a MagLIF fusion-like plasma, revealing that higher atomic number liners reduce these losses and that diffusion is confined near the ablated border.

Contribution

The paper extends previous analysis to arbitrary liner atomic numbers, providing asymptotic scaling laws for mass ablation and flux losses in MagLIF plasmas.

Findings

Higher atomic number liners reduce energy and magnetic flux losses.

Mass diffusion is confined to a thin layer at the ablated border.

Losses scale as 1/√Z₂ for large liner atomic number Z₂.

Abstract

In this paper, liner - fuel mass diffusion and the effect of the liner material on mass ablation, energy and magnetic flux losses are studied in a MagLIF fusion-like plasma. The analysis performed in [Garc\'ia-Rubio and Sanz, Phys. Plasmas 24, 072710 (2017)] is extended to liner materials of an arbitrary atomic number. The liner ablates and penetrates into the hot spot, compressing and cooling down the fuel. The magnetic flux in the fuel is lost by Nernst convection through the ablated liner - fuel interface, called ablated border. Increasing the liner atomic number leads to a reduction of both energy and magnetic flux losses in the fuel for a small and moderate magnetization values. Mass diffusion is confined within a thin layer at the ablated border. Concentration gradient and baro-diffusion are the predominant mechanisms leading to liner - fuel mixing. The width of the diffusion layer may be comparable to the turbulent mixing layer resulting from the Rayleigh-Taylor instability at the ablated border. An asymptotic analysis performed for large liner atomic number Z_{2} shows that mass ablation, energy and magnetic flux losses and liner - fuel mass diffusion scale as 1/\sqrt{Z_{2}}.