Shockwave-assisted laser filament conductivity

E. Schubert, D. Mongin, T. Produit, G. Schimmel, J. Kasparian and J.-P. Wolf, Applied Physics Letters 111, 211103 (2017) link

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 observe remote spark-free unloading, discharge suppression, and discharge guiding, respectively. These effects rely on an indirect consequence of thermal deposition, namely, the fast dilution of ions by the shockwave triggered by the filament at each laser shot. This dilution drastically limits ion-ion 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.