# 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.

## Key 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.

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Source: https://tomesphere.com/paper/1904.05640