Start-up of a pulsed plasma jet: From branching to guided streamers

When an atmospheric pressure plasma jet is operated by pulsed voltages with a kHz-range repetition frequency, guided streamers — often called plasma bullets — are typically observed. One of their most notable properties is that these guided streamers follow a predetermined path rather than branch as streamers normally do. This behavior is due to a memory effect where the remnants of previous discharges provide a guiding channel for the new streamer to follow. However, when the plasma jet is first turned on, such guiding channel cannot be present yet and consequently there must be a development phase during which the guiding channel is formed.