Characteristics of high-pressure, pulsed glow discharge in gas density depletion

High-pressure, pulsed glow discharge has been studied for the excitation discharge in TEA gas lasers. The influences of the gas density depletion on the high-pressure, pulsed glow discharge have been investigated eliminating the other instabilities, such as shock waves, residual ions, discharge products and electrode heating. The gas density depletion is produced by utilizing a subsonic gas flow between the curved electrodes. A gas mixture of helium and argon is used to simulate the excimer lasers. The comparison has been made on the single-pulse discharge occurred in the presence of the gas density depletion with the second discharge on the double-pulse experiments in a stable gas. We have found that the big gas density depletion tends to induce the arc without other instabilities. In a stable gas, on the other hand, the second discharge of the double-pulse experiments becomes the arc in much smaller gas density depletion. The arc in the highly repetitive operation might be driven by some factors other than the gas density depletion.