Shockwave-assisted laser filament conductivity

TL;DR

This paper explores how ultrashort laser filaments influence high-voltage discharges by creating shockwaves that enhance plasma conductivity, enabling remote discharge control under various conditions.

Contribution

It demonstrates the role of shockwave-induced ion dilution in modulating plasma conductivity and discharge behavior, a novel insight into laser-guided electrical discharge control.

Findings

Shockwaves from laser filaments induce ion dilution.

Laser filaments can suppress or guide discharges.

Conductivity effects persist for tens to hundreds of milliseconds.

Abstract

We investigate the influence of ultrashort laser filaments on high-voltage discharges and spark-free unloading at various repetition rates and wind conditions. For electric fields well below, close to and above the threshold for discharges, we respectively observe remote spark-free unloading, discharge suppression, and discharge guiding. These effects rely on an indirect consequence of the thermal deposition, namely the fast dilution of the ions by the shockwave triggered by the filament at each laser shot. This dilution drastically limits recombination and increases the plasma channel conductivity that can still be non-negligible after tens or hundreds of milliseconds. As a result, the charge flow per pulse is higher at low repetition rates.