High-resolution measurements of the electric field at the streamer arrival to the cathode: A unification of the streamer-initiated gas-breakdown mechanism

A time-correlated single-photon counting technique was used to verify the formation of a cathode-directed streamer inside the narrow cathode region following the interpulse phase of regular negative corona Trichel pulses in ambient air. A purely experimental approach was used to determine the spatiotemporal development of the electric field during the Trichel pulse rise with an extremely high resolution of 10 mu m and tens of picoseconds. The results confirm the positive-streamer mechanism for Trichel pulse formation and provide supportive evidence for the hypothesis that the formation of a primary cathode-directed streamer occurs always in any streamer-initiated breakdown and prebreakdown phenomena associated with cathode spot formation.