Investigations to simulate the high field characteristics of gate to cathode gaps in FEDs

In FEDs, a micro-vacuum structure is used to address each pixel. The typical dimensions of such a structure are in the micron/submicron range. A high electric field is present at the tip of the emitter to produce field emission electrons sufficient to light up the pixel on the phosphor screen. The electrical breakdown due to high fields between the gate and emitter or the gate and substrate can cause catastrophic damage in a FED. In order to investigate these issues, an experimental system, in which microtip type gaps were set-up in the micron/submicron regime, was developed. This paper addresses the high field characteristics of these microtip gaps corresponding to gap distance, vacuum pressure and conditioning.