Dynamics of controlled streamer discharge at low air pressures

Based on a brief analysis of scientific data on streamer discharges, it is proposed to classify streamer discharges into free and guided ones. Guided streamers (linear and branched) have been obtained in air at pressures from 30 to 150 Torr. The speed and structure of the glow of ionization waves at the start, during deceleration and at the branch point are determined by the method of high-speed shooting. It was found that the glow of a ionization wave consists of two parts - the main wave and its precursor. The emission of the precursor wave is much less intense than that of the main wave, and contains predominantly the 2+ band of N2, as well as the 1- band of N2+. This, and also the fact that the experiments were carried out at low air pressures, explains why this glow was not observed earlier. They can subsequently be used to build test theoretical models of the phenomenon.