Effect of mechanical polish of electrode on several breakdown characteristics of vacuum gap

For the purpose of controlling conductor surface roughness, relationships between breakdown voltage of vacuum gaps and electrode surface roughness were discussed The roughness of mechanically polished Cu and CuCr electrodes were measured by a roughness meter. Experimental formula between breakdown voltage and surface roughness were obtained for plate-to-plate gaps of both Cu and CuCr electrodes. It was shown that the discharge conditioning effect increased with reducing the value of surface roughness. The breakdown voltage depended on not only cathode surface but also anode. Moreover, for nonuniform field gaps after treating the discharge conditioning, it was found that improvement in surface roughness was not effective on increasing breakdown voltage.