Lightning discharges in variable-pressure carbon dioxide

The properties of the impulse discharge in high purity carbon dioxide under variable pressure (200-1,200 torr) were investigated. In the experiments fast lightning impulses (70 ns front) were applied to a point/plane gap. The gap separation was kept fixed at 6.5 cm. It was found that the peak current did not vary much with the pressure but the electric field did so. Another variable that was affected by the pressure was the arc diameter which turned out to be inversely proportional to the gas pressure.