Electric fields in plasmas under pulsed currents

TL;DR

This study measures the electric fields in a high-current pulsed plasma using laser spectroscopy, revealing their magnitude and velocity, and correlating them with Hall electric fields, advancing understanding of plasma behavior under pulsed currents.

Contribution

It introduces a novel 3D spatially resolved measurement technique for electric fields in pulsed plasmas, linking electric field dynamics with magnetic field propagation.

Findings

Measured peak electric field magnitude matches Hall electric field predictions.

Electric field propagation velocity aligns with magnetic front movement.

Laser spectroscopy enables detailed 3D electric field mapping.

Abstract

Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for 3D spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously.