3D Dynamics of a Premagnetized Gas-puff Z-pinch implosion

TL;DR

This study provides detailed 3D velocity measurements of a premagnetized gas-puff Z-pinch implosion, revealing how axial magnetic fields influence plasma rotation and homogeneity during stagnation.

Contribution

It offers the first comprehensive 3D velocity analysis of a premagnetized gas-puff Z-pinch, demonstrating the effects of axial magnetic fields on rotation and zippering.

Findings

Axial magnetic fields induce plasma rotation dependent on field components.

Lorentz force $J_z imes B_r$ is the main driver of rotation.

Small axial fields improve pinch homogeneity by reducing zippering.

Abstract

Detailed measurements of the 3D velocity components in an annular magnetized argon Gas-puff Z-pinch implosion driven by the Llamp\"udke\~n pulse-power generator are presented. The measurements were performed with axial magnetic fields ranging from 0.04 to 0.26 T, generated by magnetic coils placed between the generator electrodes, while the plasma parameters were obtained through a time- and spatially-resolved Collective Thomson Scattering diagnostic along three axes simultaneously. The results show that the recently observed spontaneous rotation produced by applying an axial magnetic field is dependent on both the axial and radial components of the field, and the analysis suggested that the dominant mechanism responsible for this rotation is the Lorentz force $J_z \times B_r$. Additionally, the measurements show that the zippering effect in the pinch can be reduced in the presence of even a small axial field, thereby improving the homogeneity during the stagnation phase.