On the pulsed–pulseless mode transition of negative DC corona in atmospheric nitrogen

Abstract

Pulsed mode as a common phenomenon appears in many kinds of DC corona discharge, whose characteristics can be affected by some specific factors. In this paper, an important research field of pulsed mode, pulsed–pulseless mode transition, is investigated in needle–plate electrodes in nitrogen at atmospheric pressure, and we discuss the effect of external circuit, gas temperature, and associative ionization on mode transition by experiment and simulation. The external circuit coupling with plasma can make the pulseless mode be achieved when there is a balance of charge between loss by discharge and gain by source before discharge quenches. The time-averaged gas temperature remains at 700 K which is regardless of source voltage and discharge mode, so gas heating is not a critical factor for mode transition. We investigate the effect of the associative ionization involving metastable particles by comparing the results with and without associative ionization reactions in the simulation; we find that the associative ionization is vital to determine the cathode voltage, discharge current, and the concentrative shape of discharge in the pulseless mode. Finally, we compare the pulsed–pulseless mode transition in nitrogen and air to clarify the effect of specific factors that depend on electronegativity of gas.

Selective Clipping of a Lignin-Derived Monomer by Plasma for Bio-Oil Upgrading

“…In another approach, a pin-to-plate corona discharge was used to process the guaiacol feed (Figure b). In this case, the gas-phase interactions mainly occurred at the plasma–liquid interface at temperatures above 700 K . According to the above analysis of the data presented in Figure c,d, the reaction temperature in the discharge zone determines whether the aromatic ring is hydrogenated or cracked.…”

Numerical study of the self-pulsing of DC discharge: from corona to parallel-plate configurations

“…It is thought that a transient ion sheath consisting of positive ions forms during the temporal discharge, which has an effect on pulse formation. Sun et al [19,20] compared the current pulses in nitrogen and air and found that the pulse rising edge is very similar for pulses in these two gases. They also found that the electronegativity of the working gas affects the pulsed-pulseless mode transition.…”