Sparking Potentials of and Similarity Law in Nitrous Oxide Between Coaxial Concentric Cylinders

The dc sparking potential of nitrous oxide is measured between concentric coaxial cylindrical electrodes over the gas pressure range 2 X 1O-2-81O torr for both positive and negative voltage polarities of the inner electrode. An intersection in the sparking potential and pressure curves is observed at high pressures when the sparking potential for the negative inner electrode changes from being lower to higher than the corresponding positive breakdown at a fixed gas pressure. The similarity law is found to hold in this gas only for a limited range of gas pressures. The sparking potential values are also calculated by means of an empirical general discharge concept and compared with the measured values. Reasonable agreement is obtained.