Experimental Observations of Gated Field Emitter Failures

Intrinsic failure events in gated field emitters have been studied. The gate-emitter voltage, typically 140 V during operation, drops to 10-70 V at the onset of the failure. Measurements with a diagnostic probe indicate plumes of ions and electrons are ejected into vacuum with the ion current typically 10% of the electron current. The arc voltage and the ion-to-electron current ratio are characteristic of a cathodic vacuum arc. For series resistors less than 1 kΩ, the arc is continuous, while for series resistors greater than 10 kΩ, the arc is intermittent.