Anode initiated impulse breakdown in water: the dependence on pulse rise time for nanosecond and sub-nanosecond pulses and initiation mechanism based on electrostriction

TL;DR

This study investigates how the voltage rise time influences anode-initiated impulse breakdown in water for nanosecond and sub-nanosecond pulses, highlighting electrostriction effects and nanopore formation as key mechanisms.

Contribution

It provides new insights into the dependence of streamer inception on voltage rise time and demonstrates the role of electrostriction in liquid phase breakdown mechanisms.

Findings

Breakdown depends intricately on pulse rise time.

Electrostriction causes optical density perturbations in water.

Nanopore generation explains initiation mechanisms.

Abstract

The effect of the voltage rise time on nanosecond and sub-nanosecond impulse breakdown of distilled water is studied. The dependence of anode initiated streamer inception on this parameter is shown to be more intricate than previously reported, particularly as it relates to mechanisms directly in the liquid phase. Dynamics of the emission phase for sub-nanosecond pulses with 600ps rise time are presented to enable comparison with previous work on nanosecond initiation features. Schlieren imaging is also used to show the development of optical density perturbations and rarefactions as a result of electrostriction in the liquid which were previously found for nanosecond pulses as well. The mechanism of nanopore generation in the liquid due to fast impulses proposed by Shneider, Pekker and Fridman is used to explain the results.