Current Gain in Unipolar Pulsed Discharge in Low-Pressure Carbon Dioxide

Abstract

An unipolar low-pressure pulsed discharge (0.1-0.5 Torr) in CO2 has been investigated in the frequency range 20-200 kHz with duty cycle of 0.1 to 0.85 and voltage amplitude of 600-1000 V. It was found that the current gain phenomenon, observed earlier in the mid-frequency pulsed discharges in other gases, also occurs for a discharge in CO2 with the gain of 1-2. The gain factor decreases with the discharge current growth, both due to increase of the voltage amplitude and due to increase of carbon dioxide pressure. It is shown that the shape of the oscillogram of the pulsed discharge current is determined primarily by the duration of the plasma phase and is almost independent on the duration of the afterglow phase. A physical mechanism of the phenomenon of current gain in a pulsed discharge is discussed. It is concluded that the most important factor in this mechanism is the heating of the gas in the discharge gap during the plasma phase of the discharge, which leads to depletion of neutral gas molecule concentration and, as a consequence, to ionization rate decrease.

Studying Co₂ Conversion in Dc Glow Discharge

“…This circumstance has induced a large number of papers devoted to studying the processes in gas discharges in carbon dioxide and its mixtures with other gases (see, e.g. [7][8][9][10]). Contemporary papers present the results of research into carbon dioxide conversion in discharges of ambient pressure or lowered one (hundreds Torr).…”

Burning Modes of a Bipolar Pulsed Discharge in Co2

“…However, in contrast to the radio frequency and glow discharges [10][11][12][13][14][15][16][17], the microsecond pulsed discharges are studied much less. At the same time, whereas recently a number of papers are devoted to unipolar discharge [18][19][20][21][22][23][24], the bipolar one remains to be studied much less. Therefore the subject of this paper is the structure and characteristics of the bipolar pulsed discharge in carbon dioxide causing the greenhouse effect.…”

Dc Gas Breakdown and Townsend Discharge in Co2

“…Presently the CO 2 plasma conversion [1][2][3][4][5] as well as the breakdown and properties of discharges in various technological chambers in carbon dioxide [6][7][8][9][10] attracted a large attention of researchers. It is associated with the fact that carbon dioxide is a gas whose accumulation in the Earth atmosphere gives rise to the greenhouse effect.…”