Radial electric field measurements and restrike dynamics in DC pulsed pin-ring plasma jets

Abstract

This work presents an experimental study of ionization wave propagation in a helium plasma jet ignited with a 500 ns pulsed high voltage operating with and without a secondary grounded electrode. Fast camera imaging is coupled with non-perturbative electric field measurements using a Pockels effect-based probe to analyse the ionization front (IF) dynamics. By subtracting the Laplacian electric field components, both radial and axial electric field components generated by the plasma jet are extracted and their temporal evolution is determined. The presence of a grounded electrode is shown to double the IF propagation length and induce restrikes in the inter-electrode region, as evidenced by characteristic drops in the radial electric field component. The axial evolution of the radial electric field and IF velocity is reported, together with their correlation as a function of applied voltage.