Investigating Magnetic Diffusion in HEDP Flows using Longitudinal Zeeman Splitting Spectroscopy

Magnetic diffusion is an important effect in non-ideal magnetohydrodynamic plasmas, particularly in highly dynamic scenarios with rapid field compression arising from stagnating flows and converging geometries, with implications for inertial confinement plasmas and astrophysically-relevant processes such as driven reconnection.

In this work, we investigate magnetic diffusion by measuring magnetic field profiles with high spatial resolution in various high-energy-density plasma (HEDP) testbeds on the MAGPIE pulsed power generator. We utilize an optical emission spectroscopy diagnostic based on longitudinal Zeeman splitting. Spectral lines are selected for binary splitting and Zeeman sensitivity. To resolve the relatively small Zeeman shifts expected at multi-Tesla field strengths, we isolate the longitudinal σ components, which also helps mitigate the effects of Stark broadening prevalent in these environments.