Experimental study of the cold-field electron cathode

In this paper, optical performance of CFEs fabricated from carbon nanotubes and tungsten single crystal is presented. A cold field emitter (CFE) source, which operates at room temperatures or lower, is shown to have better performance over the high temperature Schottky emitter source. Electron emission mainly due to electron tunneling at low temperatures in the cold field emission mode offers a low energy spread and smaller virtual source size. The low energy spread, smaller virtual source size, and higher brightness should result in superior imaging resolution from a CFE compared to the Schottky emitter.