Effect of Capacitance on Gain in a Transversely Pulsed CO2 Discharge

Abstract

The small signal gain of a transversely pulsed high pressure CO2 discharge has been measured as a function of the discharge driving capacitance. The gain was observed to first increase and then decrease with capacitance for the 3 gas mixes investigated. The decrease in gain is caused by heating of the gas and a degradation of the discharge from a pulsed glow to an arc discharge. The duration of the gain pulse decreased with capacitance and for a 60:0:40 CO2:He:N2 mix an absorption of up to 30% over 27 cm was observed following the gain pulse. The results of calculation of the expected temperature increase of the gas were consistent with the observed absorption. The fraction of the electrical energy distributed between the electrode ballast resistors and the amplifier discharge was constant with respect to capacitance but varied approximately inversely with gas pressure.