Streamer discharge development in long air gaps

Streamers are non-stationary plasma formations that are the precursors of a spark discharge and an integral part of the leader discharge, including during the development of lightning. At the end of the streamer channels, due to the space charge, the electric field is amplified to values ​​exceeding the breakdown field. As a result, intense ionization occurs in the streamer head, which leads to forward propagation of the streamer. Streamer discharge plays an important role in gas isolation and lightning protection, and also finds applications in various plasma applications, including medicine and plasma-assisted combustion. Changes in the pulse amplitude, and voltage rise time do not cause a significant change in the field in the streamer channel, which remains at the level E_ch ~ 5 kV/cm in the range from 5 kV to 1000 kV. The length of the streamer propagation essentially depends on the anode radius (through velocity). The field in the channel depends on the electrode radius only at small distances. The pulse rise time has practically no effect on the field in the channel, streamer velocity and propagation distance. The kinetics of ionization and recombination significantly change both the electric field in the channel and the propagation distance of the streamer.