Influence of electrodes temperature on electrical strength of vacuum gap under AC voltages

Results of investigations of the electrical strength of a vacuum gap a temperature range of 203-373 K under AC voltage are presented. Plane electrodes with rounded-off edges, of Rogowski´s profile, have been used for the investigations. The electrodes had diameters of 150 mm and were made of copper, aluminium and stainless steel. It was found that cooling the electrodes from 293 to 203 K slightly increased the breakdown voltage, and heating the electrodes from 293 to 373 K slightly decreased the breakdown voltage. The electrode temperature effect was larger for the aluminium electrodes and smallest for the stainless steel electrodes.<>