Dependence of corona discharge plasma on voltage pulse characteristics

Summary form only given. The dynamical behavior of a corona discharge plasma at atmospheric pressure has been investigated. The plasma is produced in a coaxial chamber of 1-inch inner diameter, where high voltage pulses of 10 to 30 kV are applied. The properties of the discharge plasma depend strongly on the pulse characteristics. At a voltage of less than 15 kV, a corona discharge is produced near the center electrode. Subsequently, as the applied voltage is increased, arcing begins, which appears to be due to the fact that, in the low voltage case, the self energy for instability is not sufficiently high to cause plasma disruption. Though spurious arcing occurs at higher voltages, a glow or sustained plasma dominates as the pulse repetition frequency is increased. The time-resolved discharge data show a monotonically increasing characteristic impedance with nearly constant discharge current. It appears that the plasma at the end of a pulse does not immediately disappear, but remains in the chamber to help ignite plasma at the next pulse as a seed plasma.