Composition of the Interelectrode Prebreakdown Current in High Vacuum

Abstract

Thermal rise measurements on vacuum‐insulated electrodes subjected to steady gap voltages in the range of 80 to 100 kv show that the interelectrode prebreakdown current is composed chiefly of negatively charged particles. With aluminum electrodes the negative particles outnumber the positive particles (ions) by at least 300 to 1. With steel electrodes, the ratio is greater than 1000 to 1.