SOME STUDIES OF HIGH VOLTAGE VACUUM BREAKDOWN ACROSS LARGE GAPS. INVESTIGATION OF THE PROPERTIES OF OXIDE-COATED ALUMINIUM ELECTRODES APPLICATION TO ELECTROSTATIC SEPARATORS

摘要

D.C. high voltage breakdown tests across large gaps (l to 10 cm) have been performed in the pressure range 10 -6 to 10 -3 Torr with different types of electrodes : glass and oxide-coated aluminium as cathodes, aluminium and stainless steel as anodes. Small electrodes (300 cm ) and large electrodes (15000 cm ) were tested in two different vacuum tanks. Electric fields well above 100 kV/cm have been maintained even with the large electrodes and after a very large number of sparks. Further fundamental theoretical investigations have been carried out in order to try to understand the influence of the pressure on the vacuum breakdown voltage.