The growth and collapse of streamer channels in insulating liquids

Positive pre-breakdown streamers propagate as columns of hot liquid, and in volatile fluids such as n-hexane these high temperature columns convert to high pressure vapor channels which then expand rapidly, at a rate determined by the vapor pressure of the hot liquid. In contrast to this, the slower-growing negative streamers behave as columns of vapor, driven by the electrostatic field, and opposed by hydrodynamic drag. The expansion and subsequent collapse of a negative streamer is determined by the balance between kinetic energy of the fluid and the work done by the pressure driving the process