Gasdynamic Diode: How to Stop 100-kV Streamer

TL;DR

This paper investigates how a gas-dynamic diode can control streamer propagation in air by using density discontinuities, showing that high-density barriers can prevent streamer penetration and alter discharge behavior.

Contribution

It introduces a numerical simulation study of streamer behavior across shock-induced density discontinuities, revealing conditions that block or allow streamer propagation in gases.

Findings

Streamers fail to penetrate high-density regions when density ratio exceeds 1.2.

Discontinuities cause significant changes in streamer characteristics.

Gradual density changes do not prevent streamer penetration.

Abstract

The conditions were found when the gaseous medium demonstrates a unidirectional conductivity on a short time scale; a gas density discontinuity forms a kind of "gas-dynamic diode" that allows the plasma channel to propagate in one direction and blocks its development in another. The results of a two-dimensional numerical simulation of a streamer discharge developing through a shock wave in air were presented for various neutral density discontinuities across the wave. The focus was on the case when the streamer propagated from a low density region to a high-density region. Streamer characteristics changed greatly after intersecting the shock wave. It was shown that the streamer failed to penetrate into the high-density region when the ratio between the densities in these regions was sufficiently high (> 1.2). In this case, the discharge developed along the surface between these regions after reaching the boundary between them. Streamers could penetrate into any of the high-density and low-density regions when a neutral particle density discontinuity was replaced by a gradual density change.