Electrical Breakdown between Metal Electrodes in High Vacuum. II. Experimental

Abstract

Experiments were performed in order to test the validity of the theory outlined in I. Significant theoretical parameters varied experimentally included electrode material, electrode geometry, and applied voltage pulse length. Electrode materials chosen included W, Mo, Cu, and Al. Gap spacings varied from a few tenths to a few thousandths of a centimeter at gap voltages up to 30 kV applied either continuously or in single pulses of 1 to 100 μsec duration. For all electrode materials except Al, thermal processes are the primary initiation mechanism, and experimental observations agree with the theoretical predictions of I. With electrode materials of low tensile strength such as Al, the primary cause of electrical breakdown is due to the electrostatic stress produced by the high electric field.