Electron Emission from Conductors Subjected to Intense, Short-Pulse Electric Fields.

摘要

We studied electron emission from metal electrodes subjected to. electric fields ranging from 0.5 to 2.5 MV/cm for pulse durations of 3 to 10 ns. We used two high-voltage pulsers for these tests: a 500- to 700-kV, 72-omega pulser that generated a 3-ns gaussian pulse; and a 2- MV, 60-omega pulser that generated a 10-ns flat-top pulse with a 1-ns risetime. The high voltage levels allowed emission studies using electrode spacings of several millimeters to several centimeters. Our studies emphasized bare and anodized aluminum surfaces having surface finishes that ranged from rolled stock to machined finishes of 2-400 (mu)in. roughness. We also investigated polished stainless steel and brass. Emphasis was on first-shot performance with subsequent pulses applied to check for ~possible conditioning. The background pressure was typically 5 X 0.00001 Torr.