Charge measurements and field calculations on subsonic streamers in cyclohexane

This paper presents streamer charge measurements carried out in liquid cyclohexane, and calculations of the electric field acting on the streamer. The time resolved measurement of streamer charge is made with a differential system that allows to subtract the electrode charge in order to obtain the streamer charge under impulse voltage with a high sensitivity (below 1pC). Measurements are carried out in a point plane gap versus applied voltage and hydrostatic pressure, and concern slow subsonic streamers observed in positive polarity. With the charge data obtained, and with the measured streamer size, numerical calculations of the electric field within the gaseous streamer and outside the streamer are done. This allows to calculate the voltage drop existing within the streamer, and also to determine the intensity of the electrostatic pressure acting at the gas/liquid interface.