Voltage-current characteristics of high-current glow discharges

The voltage-current characteristics of glow discharges in gas mixture (N-2:O-2=8:2) at a pressure of 10 Torr were obtained with the discharge current up to 150 A. Parallel-plane electrodes with a diameter of 10.7 cm and a discharge chamber with co-axial geometry were used to produce glow discharge with high current. The glow discharge voltage was almost constant until the whole surface of the cathode was covered with glow, i.e., until the discharge current became 3.7 A in our experimental condition (a normal glow discharge mode). The voltage, however, increased with the current when the glow covered over the cathode (an abnormal glow discharge mode). The electron density in positive column of the high-current glow discharge was obtained to be 3x10(11) cm(-3) from Langmuir probe measurements. (C) 2001 American Institute of Physics.