Thermal field forming of spindt cathode arrays

This paper describes observed changes in the emission from a 100-tip Spindt cathode array operated at peak emission levels that produced Joule heating and temperatures sufficient to cause surface self-diffusion at the tips. This well-known thermal field forming effect can produce blunting or sharpening of the emitter tips, depending on whether the thermal self-diffusion, or the field-assisted thermal diffusion dominates. A Fowler/Nordheim analysis of the emission produced the unexpected result that tip sharpening had occurred.