Conical DC Discharge in Ambient Air Using Water as an Electrode

Conical dc discharge is generated between a copper cathode with a hemispherical head (2-7 mm in diameter) and a static water anode in ambient air. The discharge is hollow and is just like an umbrella if the electrical conductivity of the water electrode is higher than 17.31 musldrcm^-1. The profile is composed of three zones with different luminosities. The effects of the discharge current, air gap length, cathode dimension, and electrical conductivity of the water electrode on the discharge are studied. Volt-ampere characteristics and images of the discharge under different experimental conditions are shown to characterize the discharge. A mechanism for stabilizing the discharge is discussed.