The impact of the Hall effect on high energy density plasma jets

TL;DR

This study investigates how the Hall effect influences the structure and density of high-energy plasma jets generated by pulsed power, revealing its significant impact on jet periphery dynamics and shape.

Contribution

It is the first to analyze the indirect effects of Hall physics on plasma jet morphology and density profiles through experiments and simulations.

Findings

Hall physics affects jet periphery flows and shape.

Hall term enhances jet density when plasma current flows away.

Experimental and simulation results are consistent.

Abstract

Using a 1-MA, 100ns-rise-time pulsed power generator, radial foil configurations can produce strongly collimated plasma jets. The resulting jets have electron densities on the order of 10^20 cm^-3, temperatures above 50 eV and plasma velocities on the order of 100 km/s, giving Reynolds numbers of the order of 10^3, magnetic Reynolds and P\'eclet numbers on the order of 1. While Hall physics does not dominate jet dynamics due to the large particle density and flow inside, it strongly impacts flows in the jet periphery where plasma density is low. As a result, Hall physics affects indirectly the geometrical shape of the jet and its density profile. The comparison between experiments and numerical simulations demonstrates that the Hall term enhances the jet density when the plasma current flows away from the jet compared to the case where the plasma current flows towards it.