Study of streamer inception under impulse voltage in liquid cyclohexane

We study streamer initiation in liquid cyclohexane, in a point-plane geometry under impulse voltage. A new differential charge measurement system, allowing a high sensitivity to be obtained under impulse voltage (below 0.1 pC), is presented. The investigations presented concern the influence of applied voltage, impulse rise time and hydrostatic pressure. Under DC voltage, the negative streamer initiation is due to an avalanche in the liquid phase, and is not affected by pressure. In contrast, positive streamer initiation shows some variation when the pressure is increased.